Experimental study on movement characteristics and influence factors of submarine landslide triggered by earthquake

Experimental study on movement characteristics and influence factors of submarine landslide triggered by earthquake | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Experimental study on movement characteristics and influence factors of submarine landslide triggered by earthquake Min Zhang, Shuai Cai, Yuelou Cai, Shiwei Shen, Yan Xu, Shulin Dai This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-4487432/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 02 Dec, 2024 Read the published version in Natural Hazards → Version 1 posted 5 You are reading this latest preprint version Abstract Earthquake-induced submarine landslides are destructive mass movement events impacting many marine environments. In this study, a novel vibrating flume tank was developed to study the macroscopic phenomenon of submarine landslide movement triggered by earthquakes. The results showed the movement of the sliding body has the characteristics of periodic and intermittent flow. The sliding body strikes the structure on the slope, and the force of the structure quickly reaches its peak value, then fluctuates near that value for a period of time before decreasing rapidly. A higher clay content enhanced the plastic deformation of the sliding body and the movement velocity of the sliding body was reduced. When the earthquake vibration frequency increased, the average velocity of the sliding body increased. The electrolyte in seawater enhances the water pressure and plays the role of lubricant. As the electrolyte concentration in the seawater increased, the velocity of the sliding body movement increased accordingly due to the lower friction. When the seabed slope gradient increased, the erosion effect of the sliding body on the seabed slope became stronger. As the volume of the sliding body increased, the movement velocity increased. This research can provide a basis for evaluating the hazards of submarine landslides, which is of great significance for preventing and avoiding disasters caused by submarine landslides. earthquake submarine landslide movement characteristic influence factor flume experiment Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 1 Introduction Submarine landslides are phenomena of submarine mud and sand flow triggered by gravity or external loads. They have large scale, high density and high sand content. They can travel along the seabed over long distances at high velocity; they occur widely in continental marginal basins and island slope zones(Wang et al. 2018 ; Hampton et al.). Submarine landslides can damage pipelines, tunnels, other underwater facilities(Dai et al. 2017 ; Dutta and Hawlader 2019 ), and may also cause secondary disasters such as tsunamis, causing even great economic losses and casualties (Hayir et al. 2008 ; Corona and Ramírez-Herrera 2015 ; Nakata et al. 2020 ). In July 1998, a submarine landslide in Papua New Guinea triggered a tsunami. The waves exceeded 15 m in height and killed more than 2000 people (Tappin et al. 2001 ). On 26 December 2006 a submarine landslide occurred in the Luzon Strait . S ubmarine optical cable s w ere broken, and communication between China and Southeast Asian countries was cut for 12h (Hsu et al. 2006). In the context of the accelerated development of marine resources, subsea engineering facilities, such as subsea drilling platforms, communication cables, subsea oil storage tanks, and artificial islands, will increase. Submarine landslides inevitably pose a huge threat to the safety of many f uture offshore and coastal projects (Masson et al. 2006 ; Poupardin et al. 2020 ). Therefore, the study of the movement characteristics of submarine landslides can help to understand this natural phenomenon in depth and provide a basis for evaluating the hazards, which is of great significance in preventing and avoiding future disasters. The research methods for submarine landslides include physical model experiments (the lab based investigations), theoretical models, and numerical simulations. Owing to the limitations of environmental and technical conditions, it is difficult to directly observe the destruction process of submarine slopes. Therefore, physical model experiments remain an effective method for studying submarine landslides. SCHWARZ(1982) conducted an earlier flume experiment to study the deposition rate and thickness of submarine landslides, and Ataie-Ashtiani and Najafi-Jilani ( 2008 ) conducted 120 sets of experiments to study the waves generated by submarine landslides and obtained very useful data. Zakeri et al. ( 2008 ) gave a new definition of the Reynolds number and proposed a method for estimating the drag forces upon impact with submarine debris flows normal to the pipeline axis. Elverhoi et al. ( 2010 ) studied the movement state of submarine landslides with different clay content. The results indicated that the sliding body produced a layered movement phenomenon when the clay content was low. Sequeiros ( 2012 ) conducted indoor experiments and obtained the flow conditions of gravity flow. An et al ( 2016 ) studied the influence of the clay content of the sliding body on the deposition process of a submarine landslide. Takahashi et al. ( 2020 ) used centrifuge simulation experiments to provide insights into the initiation mechanism of sandy and silty submarine landslides and their flow and depositional characteristics under seismic and liquefaction effects. Carey et al. ( 2019 ; 2022) based on dynamic backpressure shear box experiments, found that landslides may undergo cyclic sliding under prolonged high-amplitude ground shaking, and elucidated the effects of pore water pressure and dynamic stress changes on slow landslide displacements. Sørlie ( 2023 ) did 21 physical model tests to study the velocity, migration distance and impact force of clay-rich submarine landslides on foundation columns. Silver ( 2023 ) through flume experiments, found that non-tsunamigenic submarine slope failures can be induced under overpressure conditions in low-permeability, high-cohesion sediments. In terms of theoretical model research, Pudasaini ( 2012 ) proposed a generalised two-phase debris flow model that can better describe the complex dynamics of submarine landslides and related phenomena. Buss et al. ( 2019 ) proposed a formation and evolution process of submarine landslides based on the kinematic balance method. In numerical simulations, Liu ( 2015 ) used computational fluid dynamics (CFD) to study the impact force of submarine landslides on offshore pipelines and established empirical formulas for estimating normal and axial impact forces, while An et al. ( 2016 ) used smoothed-particle hydrodynamics (SPH) to simulate the evolution process of submarine landslides and found that the sliding body was strongly deformed during the impact. Mao et al. ( 2020 ) proposed a new discrete element method for solving CFD, which can more accurately simulate the interaction between fluid fields in the process of submarine landslides. Wu et al. ( 2023 ) proposed a CFD-DEM method considering the influence of non-spherical particles, analyzed the influence of particles on the process of submarine landslide collapse, and explored the process and characteristics of soil particles filling with water. Despite these advances, physical model experiments (the lab based investigations) remain the main method for studying submarine landslides. In physical model experiments, researchers mostly use mud dumping into a quiet water environment to simulate landslides, ignoring the formation conditions of submarine landslides and ocean hydrodynamic factors. Scholars have mostly conducted research on the movement state of landslides, but few studies have systematically and comprehensively summarized the movement characteristics of submarine landslides. In this study, a novel vibrating flume tank was constructed to comprehensively study the movement characteristics of submarine landslides triggered by earthquakes. It studies the macroscopic phenomena of submarine landslide triggered by earthquake, analyzes the velocity variation of landslide, and the stress of slope structures in different positions during landslide movement. And also, the influence of clay content of landslide, seismic vibration frequency, electrolyte concentration in seawater and submarine slope on the migration characteristics of submarine landslide is studied. The results of this study will make us further understand the characteristics of submarine landslides, and is of great significance to the construction and protection of marine engineering facilities. 2 Methods 2.1 Equipment and materials A scale model experiment was used in this research. The ratio of similitude was calculated using dimensional analysis, as shown in Table 1 . In flume experiments, scholars have widely used mudflow to simulate a sliding body. Mudflow is made by mixing kaolin, silt, and water in a certain proportion(Ilstad et al. 2004 ; Cai et al. 2018 ). Therefore, the experimental sliding body was configured based on previous research and experience. The sliding body was configured according to the particle size distribution range of the offshore seabed soil listed in Table 2 and the experimental requirements(Bornhold et al. 1986 ; Yang 1987 ; Saito et al. 2001 ). Table 1 Similarity ratio of model simulation experiment Table 2 The particle size distribution of offshore seabed soil Particle size grade Particle diameter (mm) Content(%) Coarse particle 0.25 − 0.075 40–60 Powder particle 0.075 − 0.005 20–40 Clay particles < 0.005 < 30 The internal dimensions of the flume were 2.4m long, 0.3m wide and 1.2m high. A vibrating tank was set up to simulate the earthquake source region and avoid the boundary effect caused by the overall vibration of the flume. The internal dimensions of the vibrating tank were 0.4m long, 0.3m wide and 0.4m high. An outer tank was connected to the flume and the vibration tank. The internal dimensions of the outer tank were 0.5m long, 0.4m wide and 0.5m high. A removable baffle was set between the vibrating tank and flume. A schematic of the equipment is shown in Fig. 1 . 2.2 Experiment process A seabed slope was constructed in a flume to simulate the initial terrain conditions. The seabed slope height was 0.7 meters. The seabed slope gradient was modified according to different experimental requirements. The remaining part on the left side of the flume (refer to Fig. 1 (c)) was the horizontal accumulation area. The horizontal accumulation area was laid with fine sand. Silty sand with a height of 20 cm, length of 40 cm, and width of 30 cm was placed in the vibrating tank to simulate a sliding body in the source region. To analyse the force of the sliding seabed, soil pressure sensors T-1, T-2, and T-3 were arranged at a height of 1–2 cm from the surface of the seabed slope (refer to Fig. 1 (c). The horizontal distances between the three soil pressure sensors and the top of the seabed slope were 30, 90, and 150 cm, respectively. To monitor the pore water pressure changes in the sliding body and determine the start time of the sliding body movement, a pore water pressure sensor was buried at a depth of 10 cm inside the sliding body in the source region. After the sensors were arranged, water was slowly poured into the flume so that the water levels in both the flume and the vibrating tank were level. The height of the water injection was 1m. When the sliding body liquefied under the action of the seismic load, it began to slide. To determine the time at which the sliding body started to slide down in the experiment, the strain value when the sliding body liquefies was calculated prior to the experiment. When the sand was completely liquefied, the pore water pressure measured by the pore water pressure sensor was the total stress. The experiment showed that the saturated unit weight of sand was 18.7kN/m 3 , and the total stress was 3.87kPa. The calibration coefficient of the pore-water pressure sensor was 0.02706. The calculated strain value of sliding-body liquefaction was 143µε. In the experiment, the switch button of the motor was adjusted to grades 1–8 according to the requirements. The vibrating tank was operated at a vibration frequency of 1–8 Hz and vibration amplitude of 2 cm. The magnitude of the vibration frequency represented the simulated seismic frequency in the experiment. The change in the strain value of the pore-water pressure sensor in the tank was monitored using a strain gauge. When the strain value reached 143µε, the sliding body liquefied. At this time, the baffle of the vibrating tank was pulled away, and the landslide soil body began to slide downward under the action of vibration load and gravity. The change in the soil pressure sensor value was monitored during the experiment, and the macroscopic phenomenon in the flume was photographed using a high-speed camera. After the experiment, the flume was rested for 2–3 h to precipitate the suspended soil particles. Morphological changes in the seabed slope and the accumulation form of the landslide soil after the landslide flow were observed. 3 Results and discussion In the experiment, the clay content of the sliding body, earthquake vibration frequency, electrolyte concentration, and seabed slope gradient were controlled separately. Multiple sets of experiments were conducted to determine the movement characteristics of a submarine landslide triggered by an earthquake. This section describes one set of experiments as an example (the seabed slope gradient was 20°, the clay content of the sliding body was 20%, the earthquake vibration frequency was 3 Hz, and no electrolyte was added to the water) to illustrate the movement characteristics of submarine landslides triggered by earthquakes. The forces of the seabed slope structures at different locations in the process of submarine landslides were analysed. 3.1 Movement characteristics 3.1.1 Macroscopic phenomenon After the sand in the vibrating tank was liquefied, the baffle at the connection between the vibrating tank and flume was pulled out, and the liquefied sand in the vibrating tank flowed out, sliding on the prefabricated seabed slope, and forming a landslide. The experimental process is illustrated in Fig .2. In terms of the movement process, the head of the sliding body was high and steep, the middle section was conical, and the water content of the tail was high. With erosion occurring in the process of movement and mixing of water, particle dispersion occurred in the sliding body. For fine particles, because the upward buoyancy provided by the pore water pressure was greater than gravity, fine particles moved upward. For coarse particles, because gravity was greater than buoyancy, the coarse particles remained in the sliding body and continued to move. Therefore, overall, the upper soil layer of the sliding body was loose, forming the low-density flow, and the boundary line of the low-density flow was in the shape of a wave bending in the opposite direction of movement, while the coarse particles in the sliding body were constantly concentrated, forming the high-density flow. The surfaces of the seabed slope and horizontal accumulation area were observed after the experiment. Soil erosion and sedimentation in the flume are shown in Fig. 3 . The seabed slope surface was uneven and contained gullies. This was because the surface of the slope was eroded during the sliding body movement, and at the same time, soil particles continued to deposit. In the horizontal accumulation area, the gullies were not obvious, and the soil was significantly thicker than before the experiment. This was because the horizontal accumulation area was dominated by sedimentation, the particle size of the lower layer of the sedimentary layer was coarse, the particle size of the upper layer was fine, and the entire layer was stacked. 3.1.2 Velocity research The experiment was repeated three times to reduce the possibility of errors in the experiment. CAD was used to draw the contour line of the sliding body at each moment in the flume (recorded from 2s, with an interval of 1s). Sliding body movement velocities were calculated based on the contour line. The movement velocity-time relationship curves of the three parallel experiments are shown in Fig. 4 . By analyzing the movement velocity-time relationship curves of the sliding body and the movement pattern of the head of the sliding body at different times ( Fig. 5 ) , it can be concluded that the velocity of the sliding body was not uniform during the movement. The movement of a sliding body has the characteristics of periodic and intermittent flow. In the first 3s of movement, the movement velocity was high under the action of gravity owing to the large amount of material in the sliding body. At approximately 4s, the velocity of the sliding body reached its maximum value. Subsequently, owing to the resistance of the seabed slope surface, some soil particles were deposited, and the kinetic energy was rapidly reduced; thus, the velocity of the sliding body was greatly reduced. From 5s to 6s, the slope of the head of the sliding body became steeper, indicating that the soil particles at the head were gathering, and the velocity increased gradually owing to the resistance along the way. At approximately 6s, the head of the sliding body experienced critical failure, the sliding body velocity reached its peak, and then the velocity decreased rapidly. Between 8 and 10s, the particles in the head of the sliding body continuously accumulated, and the movement velocity of the sliding body increased. At approximately 10 s, the head of the sliding body collapsed and the velocity reached its peak. Subsequently, the velocity of the sliding body decreased and then gradually increased after 11s. The sliding body moved to the horizontal area in 14s, and then the movement velocity decreased gradually owing to the influence of the resistance. The reasons for this process are as follows. During the movement of the sliding body, the coarse particles are continuously concentrated in the head. When the driving force behind the sliding body is insufficient to promote head movement, the head movement velocity decreases, and the particles behind the head are continuously transported to the head by water, which leads to the expansion of the head of the sliding body and an increase in slope declination. The movement of the sliding body has periodicity, and each period can be decomposed into the following three stages. In the first stage, the rear driving force of the sliding body is insufficient, resulting in a decline in the movement velocity, and the rear soil particles continue to accumulate in the head. In the second stage, with the accumulation of soil particles, the front slope of the sliding body head increases, forming an additional slope declination. In the third stage, after the sliding body head reaches the additional slope declination of the critical failure, the head collapses, and the velocity of the sliding body increases. 3.1.3 Force analysis The values of the soil pressure sensors above the seabed slope can reflect the force of the seabed slope structures at different positions during the sliding body movement. Before the experiment, the strain values of the T-1, T-2, and T-3 soil pressure sensors were monitored with time under hydrostatic pressure for 10s. The values are listed in Table 3 . Table 3 Strain value of sensor in 10s under hydrostatic pressure (×10 − 6 ) Time(s) T-1 T-2 T-3 1 136 207 292 2 138 210 295 3 144 208 297 4 138 212 293 5 142 210 290 6 141 204 288 7 145 202 291 8 146 199 293 9 148 198 297 10 142 200 294 It can be seen from Table 3 that the strain values produced by the water pressure changed within a certain range, which might be caused by the sensor's own error or the slight disturbance of water. The average strain values of sensors T-1, T-2, and T-3 in quiet water were 142×10 − 6 , 205×10 − 6 , and 293×10 − 6 , respectively. The calibration coefficients of the three sensors were 0.02706, 0.02694, and 0.02726, respectively. Therefore, the pressures measured by the three sensors were 3.8 kPa, 5.5 kPa, and 8.0 kPa, respectively. The distances from the centre of the circular sensor sheets of the T-1, T-2, and T-3 sensors to the water surface were 41, 62, and 86 cm, respectively, and the actual water pressures generated at each height were 4.1kPa, 6.2kPa, and 8.6kPa. The errors were not significantly different, and the results were still of research significance. In the experiment, the strain value of the soil pressure sensor minus the average strain value under hydrostatic pressure were used to obtain the strain value of the seabed slope structures at different positions at each moment of the sliding body movement. The strain-time relationship curves for the three sets of parallel experiments are shown in Fig. 6 . According to Fig. 6 , the influence of the sliding body and vibration load on the seabed slope structure was not obvious at the beginning of the movement. With the downward movement of the sliding body, the force on the structure strengthened, and the strain of the structure gradually increased. When the sliding body moved to the position of the slope structure, the strain in the structure changed abruptly and reached a peak value. Then, the head of the sliding body moved forward, the structure was still affected by the impact of the particles inside the sliding body, and the impact force fluctuated near the peak. After most of the sliding body passed through the structure, it was still impacted by the residual flowing sand. Simultaneously, the strain gradually decreased and finally stabilized. 3.2 Influence factors on the movement characteristics In this section, the factors influencing the movement characteristics of submarine landslides, such as the clay content of the sliding body, earthquake vibration frequency, electrolyte concentration in seawater, and seabed slope gradient are discussed. 3.2.1 Clay content The experimental conditions were as follows: the seabed slope gradient was 20°, earthquake vibration frequency was 3 Hz, no electrolyte was added to the water, no glass plates were laid on the seabed slope surface, and the clay content of the sliding body was changed to 5%, 10%, and 15%. Three sets of parallel experiments were conducted to reduce the possibility of errors in the experiment. The movement contour diagrams of the sliding body at 5s, 10s, and 15s in the three sets of experiments are shown in Fig. 7 . The movement contour diagrams show that at each observed time, the horizontal migration distance of the sliding body decreased with an increase in clay content. The average velocities of the sliding bodies in the three sets of experiments were 18.3 cm/s, 15.2 cm/s, 12.3 cm/s respectively, and the average velocities of movement in the horizontal accumulation area were 16.0 cm/s, 15.1 cm/s, 12.5 cm/s respectively. This is because the hydration of clay particles reduced the free water in the soil and weakened the lubrication between particles; thus, the plastic flow deformation of the sliding body was enhanced, and the friction force increased, consequently the movement velocity was reduced. In repeated experiments, glass plates were laid on the seabed slope surface to study the accumulation characteristics of submarine landslides. The results are presented in Table 4 . Table 4 Accumulation of submarine landslide soil at different clay content Clay content Horizontal zone Seabed slope Source region Total Soil amount (kg) Proportion (%) Soil amount (kg) Proportion (%) Soil amount (kg) Proportion (%) Soil amount (kg) Proportion(%) 5% 7.63 30.1 6.77 26.7 10.95 43.2 25.35 100 10% 8.10 32.6 6.66 26.8 10.09 40.6 24.85 100 15% 9.81 36.8 7.53 28.3 9.28 34.9 26.62 100 The results show that when the clay content of the sliding body was higher, more soil particles accumulated in the seabed slope and horizontal accumulation area. This was because, as the clay particle content increased, the soil particles become denser, and the interaction between particles was strengthened. Therefore, the erosion and deposition during the movement of the sliding body were strengthened, and the movement velocity decreased. 3.2.2 Vibration Frequency The experimental conditions were as follows: the clay content of the sliding body was 10%, the seabed slope gradient was 20°, no electrolyte was added to the water, no glass plates were laid on the seabed slope surface, and the earthquake vibration frequency was changed to 2 Hz, 3 Hz, and 4 Hz. Three sets of parallel experiments were conducted to reduce the possibility of errors in the experiment. The movement contour diagrams of the sliding body at 5s, 10s, and 15s in the three sets of experiments are shown in Fig. 8 . The movement contour diagrams show that at each observed time the horizontal movement distance of the sliding body increased with an increase in the seismic vibration frequency. The average velocities of the sliding bodies in the three sets of experiments were 15.2 cm/s, 14.1 cm/s, 17.5 cm/s respectively, and the average velocities of movement in the horizontal accumulation area were 14.5 cm/s, 13.8 cm/s, 16.1 cm/s respectively. These data show that the average movement velocity of the sliding body increased with an increase in the vibration frequency. This was because with an increase in vibration frequency, the mass of the sliding body in liquefaction in the source region increased. In addition, with an increase in vibration frequency, the diffusion of clay particles at the source region became greater, and the floating of large soil particles increased the density of the low-density layer of the landslide. In repeated experiments, glass plates were laid on the seabed slope surface to study the accumulation characteristics of submarine landslides. The results are presented in Table 5 . Table 5 Accumulation of submarine landslide soil at different vibration frequency Vibration frequency Horizontal zone Seabed slope Source region Total Soil amount (kg) Proportion (%) Soil amount (kg) Proportion (%) Soil amount (kg) Proportion (%) Soil amount (kg) Proportion (%) 2Hz 5.73 22.8 5.71 22.7 13.69 54.5 25.13 100 3Hz 8.10 32.6 6.66 26.8 10.09 40.6 24.85 100 4Hz 7.72 34.4 6.82 30.4 7.91 35.2 22.45 100 It can be observed from the results that with an increase in the vibration frequency, the sliding body is more likely to lose stability. This is because the vibration frequency increased the degree of liquefaction of the sliding body in the seabed slope, and the quality of the sliding soil increased. 3.2.3 Electrolyte concentration The concentration of electrolyte in seawater is approximately 3.6 g/L, of which Na + , Cl − , and Mg 2+ have the highest content. NaCl accounts for more than 80% of the total mass. Therefore, NaCl and a small amount of MgCl 2 were selected as research variables in the experiment. The experimental conditions were as follows: the clay content of the sliding body was 10%; the seabed slope gradient was 20°; the earthquake vibration frequency was 3 Hz; no glass plates were laid on the seabed slope surface; and the electrolyte concentration in the water was changed to 0, 3.6 g/L, and 7.2 g/L. Three sets of parallel experiments were conducted to reduce the possibility of errors in the experiment. The movement contour diagrams of the sliding body at 5s, 10s, and 15s in the three sets of experiments are shown in Fig. 9 . The movement contour diagrams show that at each observed time the horizontal movement distance of the sliding body increased with an increase in the electrolyte concentration. The average velocities of the sliding bodies in the three sets of experiments were 15.2 cm/s, 15.9 cm/s, 17.9 cm/s respectively, and the average velocities of movement in the horizontal accumulation area were 14.5 cm/s, 14.5 cm/s, 16.4 cm/s respectively. This was because the electrolyte in the seawater increased the water pressure and sliding force of the sliding body. In addition, the electrolyte had a lubricating effect and reduced the resistance of the sliding body. In repeated experiments, glass plates were laid on the seabed slope surface to study the accumulation characteristics of submarine landslides. The results are presented in Table 6 .It can be seen from the results that the mass of the sliding body decreased with an increase in the electrolyte concentration. This was because the lubrication of the electrolyte made it difficult for the soil particles to deposit on the seabed slope, and the lubrication also weakened the interaction between the soil particles. Therefore, the liquefaction of the sliding body did not occur easily, and the quality of the sliding soil was reduced. Table 6 Accumulation of submarine landslide soil with different electrolyte concentrations Electrolyte concentration Horizontal zone Seabed slope Source region Total Soil amount (kg) Proportion (%) Soil amount (kg) Proportion (%) Soil amount (kg) Proportion (%) Soil amount (kg) Proportion (%) 0 8.10 32.6 6.66 26.8 10.09 40.6 24.85 100 3.6g/L 9.69 35.1 6.22 22.5 11.72 42.4 27.63 100 7.2g/L 8.85 34.0 5.32 20.4 11.87 45.6 26.04 100 3.2.4 Seabed slope gradient The experimental conditions were as follows: the clay content of the sliding body was 10%, the earthquake vibration frequency was 3 Hz, no electrolyte was added to the water, no glass plates were laid on the seabed slope surface, and the seabed slope gradient was changed to 30°, 20°, and 10°. Three sets of parallel experiments were conducted to reduce the possibility of errors in the experiment. The movement contour diagrams of the sliding body at 5s, 10s, and 15s in the three sets of experiments are shown in Fig. 10 . The movement contour diagrams show that at each observed time, the horizontal movement distance of the sliding body increased with an increase in the seabed slope gradient. The average velocities of the sliding bodies in the three sets of experiments were 15.9 cm/s, 15.2 cm/s, 14.1 cm/s respectively. This was because, when the seabed slope gradient increased, the soil particles in the sliding body were not easily deposited on the seabed slope surface under the influence of gravity. The movement of the sliding body was intense, and the erosion on the seabed slope surface was increased. Thus, the volume of the sliding body increased, and the movement velocity increased. In repeated experiments, glass plates were laid on the seabed slope surface to study the accumulation characteristics of submarine landslides. The results are presented in Table 7 . Table 7 Accumulation of submarine landslide soil at different seabed slope gradients Seabed slope gradient Horizontal zone Seabed slope Source region Total Soil amount (kg) Proportion (%) Soil amount (kg) Proportion (%) Soil amount (kg) Proportion (%) Soil amount (kg) Proportion (%) 30° 8.10 32.6 6.66 26.8 10.09 40.6 24.85 100 20° 9.82 38.7 5.05 19.9 10.51 41.4 25.38 100 10° 5.21 24.5 7.13 32.8 10.82 42.7 23.16 100 It can be seen from the experimental results that when the seabed slope gradient was 30° or 20°, the amount of accumulated soil on the seabed slope was smaller than that in the horizontal accumulation area. When the seabed slope gradient was 10°, the amount of soil accumulated on the seabed slope was greater than that in the horizontal accumulation area. With a decrease in the seabed slope gradient, the sliding body was prone to deposition 4 Conclusions This study used a novel vibrating flume tank to study the macroscopic phenomenon of the movement of submarine landslides triggered by earthquakes. The movement velocity of the sliding body and force of the seabed slope structures at different positions were analyzed. The factors influencing the movement characteristics of submarine landslides, including the clay content of the sliding body, earthquake vibration frequency, electrolyte concentration in seawater, and seabed slope gradient were discussed. The conclusions are as follows. During the movement, the head of the sliding body was high and steep, the middle part was conical, and the water content of the tail was high. With erosion in the process of movement and the mixing of water, the sliding body was divided into high-density and low-density flows. The low-density flow in the upper layer produced a wave shape opposite to the direction of motion at the water-soil interface owing to the uneven velocity. The surface of the seabed slope was dominated by erosion, a large number of gullies were formed. The particle size of the lower sedimentary layer was coarse, the upper particle size was fine, and the entire layer was stacked. The movement of a sliding body has the characteristics of periodic and intermittent flow. When the sliding body impacts the structure, the force of the structure rapidly reaches its peak, and then the impact force fluctuates around the peak for a period of time and then decreases rapidly. In the hazard assessment of submarine landslides, the clay content of the sliding body, electrolyte concentration in the surrounding seawater, and seabed slope gradient should be considered. The plastic deformation of the sliding body with a high clay content is evident. The electrolyte in seawater increases the water pressure and plays the role of a lubricant. Therefore, the sliding body moved faster at high electrolyte concentrations. When the seabed slope gradient increased, the erosion of the sliding body on the seabed slope was enhanced, which increased the volume of the sliding body and accelerated the movement velocity. In addition, the earthquake vibration frequency affected the size and movement of the sliding body. The increase in earthquake vibration frequency makes it easier for landslides to occur and makes the movement velocity of the sliding body faster. Declarations Acknowledgment：The authors would like to thank the reviewers who helped modify the language and provided valuable comments, and also thank Weilong Zhang and Shaolong Zhang who helped to do the experiment. Funding This work was supported by the National Science Foundation of China (Grant No. 41502322), and Science and technology development project of Jilin Province, China (Grant No. 20220101166JC). Author Contributions All authors have contributed to the conception and design of the study. Material preparation, test operation, data collection, and analysis were conducted by YueLou Cai and Shuai Cai. The first draft of the manuscript was written by Min Zhang and Shuai Cai. Writing - review and editing were performed by Min Zhang. The validation was performed by Shiwei Shen and Shulin Dai. Project administration was managed by Yan Xu. All authors have read and approved the final manuscript. Conflict of interest The author declares that they have no confict of interest. Ethical approval The study did not involve any human or animal experiments. References An Y, Shi CQ, Liu QQ, Yang SH (2016) Study on post-failure evolution of underwater landslide with SPH method In The 7th International Conference on Computational Methods (ICCM2016). Ataie-Ashtiani B, Najafi-Jilani A (2008) Laboratory investigations on impulsive waves caused by underwater landslide. Coastal Engineering, 55(12), 989-1004. Bornhold BD, Yang Z-S, Keller GH, et al (1986) Sedimentary framework of the modern Huanghe (Yellow River) delta. Geo-Mar Lett 6:77–83. https://doi.org/10.1007/BF02281643 Buss C, Friedli B, Puzrin AM (2019) Kinematic energy balance approach to submarine landslide evolution. Canadian Geotechnical Journal, 56(9), 1351-1365. Cai Y, Nie L, Zhang M, et al (2018) Analysis of the Motion and Dynamic Characteristics of Subaqueous Debris Flows. EKOLOJI 27:1–7 Carey JM (2022) Episodic movement of a submarine landslide complex driven by dynamic loading during earthquakes. Geomorphology, 2022, 408: 108247. Carey JM, Massey CI, Lyndsell B, Petley DN (2019) Displacement mechanisms of slow-moving landslides in response to changes in porewater pressure and dynamic stress. Earth Surf Dyn 7:707–722. https://doi.org/10.5194/esurf-7-707-2019 Corona N, Ramírez-Herrera M-T (2015) Did an underwater landslide trigger the June 22, 1932 tsunami off the Pacific coast of Mexico? Pure Appl Geophys 172:3573–3587. https://doi.org/10.1007/s00024-015-1171-1 Dai Z, Wang F, Nakahara Y (2017) Experimental Study on Impact Behavior of Submarine Landslides on Communication Cables. In: Advancing Culture of Living with Landslides. Springer, Cham, pp 617–622 Dutta S, Hawlader B (2019) Pipeline–soil–water interaction modelling for submarine landslide impact on suspended offshore pipelines. Géotechnique 69:29–41. https://doi.org/10.1680/jgeot.17.P.084 Elverhoi A, Breien H, De Blasio FV, et al (2010) Submarine landslides and the importance of the initial sediment composition for run-out length and final deposit. Ocean Dyn 60:1027–1046. https://doi.org/10.1007/s10236-010-0317-z Hampton MA, Lee HJ, Locat J Submarine landslides. Reviews of geophysics, 34(1), 33-59. Hayir A, Seseogullari B, Kilinc İ, et al (2008) Scenarios of tsunami amplitudes in the north eastern coast of Sea of Marmara generated by submarine mass failure. Coast Eng 55:333–356. https://doi.org/10.1016/j.coastaleng.2007.12.001 Hsu S K, Tsai C H, Ku C Y, et al. Flow of turbidity currents as evidenced by failure of submarine telecommunication cables[C]//International Conference on Seafloor Map** for Geohazard Assessment, Extended Abstracts, Rendiconti online, Società Geologica Italiana. 2009, 7: 167-171. Ilstad T, De Blasio FV, Elverhoi A, et al (2004) On the frontal dynamics and morphology of submarine debris flows. Mar Geol 213:481–497. https://doi.org/10.1016/j.margeo.2004.10.020 Liu J (2015) Impact forces of submarine landslides on offshore pipelines. Ocean Engineering, 95, 116-127. Mao J, Zhao L, Di Y, et al (2020) A resolved CFD–DEM approach for the simulation of landslides and impulse waves. Comput Methods Appl Mechanics and Engineering, 359, 112750. Masson DG, Harbitz CB, Wynn RB, et al (2006) Submarine landslides: processes, triggers and hazard prediction. Philos Trans R Soc Math Phys Eng Sci 364:2009–2039. https://doi.org/10.1098/rsta.2006.1810 Nakata K, Katsumata A, Muhari A (2020) Submarine landslide source models consistent with multiple tsunami records of the 2018 Palu tsunami, Sulawesi, Indonesia. Earth Planets Space 72:1–16. https://doi.org/10.1186/s40623-020-01169-3 Poupardin A, Calais E, Heinrich P, et al (2020) Deep submarine landslide contribution to the 2010 Haiti earthquake tsunami. Nat Hazards Earth Syst Sci 20:2055–2065. https://doi.org/10.5194/nhess-20-2055-2020 Pudasaini SP (2012) A general two‐phase debris flow model. J Geophys Res Earth Surf 117:2011JF002186. https://doi.org/10.1029/2011JF002186 Saito Y, Yang ZS, Hori K (2001) The Huanghe (Yellow River) and Changjiang (Yangtze River) deltas: a review on their characteristics, evolution and sediment discharge during the Holocene. GEOMORPHOLOGY 41:219–231. https://doi.org/10.1016/S0169-555X(01)00118-0 SCHWARZ HU (1982) Subaqueous slope failures ― Experiments and modern occurrences. Subaqueous Slope Fail ― Exp Mod Occur 11. Sequeiros OE (2012) Estimating turbidity current conditions from channel morphology: A Froude number approach. J Geophys Res Oceans 117:2011JC007201. https://doi.org/10.1029/2011JC007201 Silver MMW (2023) Cohesion, permeability, and slope failure dynamics: Implications for failure morphology and tsunamigenesis from benchtop flume experiments. Marine Geology 462: 107079. Sørlie ER (2023) Physical model tests of clay-rich submarine landslides and resulting impact forces on offshore foundations. Ocean Engineering, 2023, 273: 113966. Takahashi H, Fujii N, Sassa S (2020) Centrifuge model tests of earthquake-induced submarine landslide. Int J Phys Model Geotech 20:254–266. https://doi.org/10.1680/jphmg.18.00048 Tappin DR, Watts P, McMurtry GM, et al (2001) The Sissano, Papua New Guinea tsunami of July 1998 — offshore evidence on the source mechanism. Mar Geol 175:1–23. https://doi.org/10.1016/S0025-3227(01)00131-1 Wang F, Dai Z, Nakahara Y, Sonoyama T (2018) Experimental study on impact behavior of submarine landslides on undersea communication cables. Ocean Eng 148:530–537. https://doi.org/10.1016/j.oceaneng.2017.11.050 Wu H, Xiong H, Chen X (2023) Particle shape effects on submarine landslides via CFD-DEM. Ocean Engineering，2023，284: 115140． Yang B (1987) Study of the influence of sediment loads discharged from Huanghe River on sedimentation in the Bohai and Yellow seas. Deep Sea Res Part B Oceanogr Lit Rev 34:757. https://doi.org/10.1016/0198-0254(87)90177-4 Zakeri A, Høeg K, Nadim F (2008) Submarine debris flow impact on pipelines — Part I: Experimental investigation. Coastal engineering, 55(12), 1209-1218. Cite Share Download PDF Status: Published Journal Publication published 02 Dec, 2024 Read the published version in Natural Hazards → Version 1 posted Reviewers agreed at journal 24 Jun, 2024 Reviewers invited by journal 23 Jun, 2024 Editor invited by journal 22 Jun, 2024 Editor assigned by journal 02 Jun, 2024 First submitted to journal 01 Jun, 2024 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-4487432","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":318026264,"identity":"d66a351a-b87e-47f4-836d-0e4e3451d76f","order_by":0,"name":"Min Zhang","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA6klEQVRIiWNgGAWjYDACCShpf7yx+cEHAxs54rUwnDncZjijIM2YWC1AcCO9QZrnw+FEgjrkZzc/e/g1xyKPcUZig7GNAXMCA/vhoxvwaWGcc8zcWHabRDEzz8OGxzkGbHkMPGlpN/BpYZZIMJOW3CaR2MYOtCXHgKeYQYLHDK8WNon0b2AtPQyJDdIWBhKJDYS08EjkmEl+BGqZwQHUwmBgQFiLhEROmTQjUMsGnoNthj0GCcZshPwiPyN9m+TPbXWJG9jbHz/48ee/HD/74WN4tYAAMw+K7wgpBwHGH8SoGgWjYBSMgpELAKCmSHNSMQiNAAAAAElFTkSuQmCC","orcid":"https://orcid.org/0000-0001-5851-1303","institution":"Jilin University","correspondingAuthor":true,"prefix":"","firstName":"Min","middleName":"","lastName":"Zhang","suffix":""},{"id":318026265,"identity":"8f6ddb9e-dfa1-4e29-be8e-03d3161ea12d","order_by":1,"name":"Shuai Cai","email":"","orcid":"","institution":"Jilin University","correspondingAuthor":false,"prefix":"","firstName":"Shuai","middleName":"","lastName":"Cai","suffix":""},{"id":318026266,"identity":"5cd5b40d-dfcf-407a-a6ed-c34f1451f844","order_by":2,"name":"Yuelou Cai","email":"","orcid":"","institution":"Jilin University","correspondingAuthor":false,"prefix":"","firstName":"Yuelou","middleName":"","lastName":"Cai","suffix":""},{"id":318026267,"identity":"0d95d8cc-d218-4a95-8e07-35897b98f6ed","order_by":3,"name":"Shiwei Shen","email":"","orcid":"","institution":"JLU: Jilin University","correspondingAuthor":false,"prefix":"","firstName":"Shiwei","middleName":"","lastName":"Shen","suffix":""},{"id":318026268,"identity":"181d01fc-f122-4658-8f85-dcb07f932f9b","order_by":4,"name":"Yan Xu","email":"","orcid":"","institution":"Jilin University","correspondingAuthor":false,"prefix":"","firstName":"Yan","middleName":"","lastName":"Xu","suffix":""},{"id":318026269,"identity":"56c64296-5fbb-4552-b11c-639d2d674304","order_by":5,"name":"Shulin Dai","email":"","orcid":"","institution":"Jilin University","correspondingAuthor":false,"prefix":"","firstName":"Shulin","middleName":"","lastName":"Dai","suffix":""}],"badges":[],"createdAt":"2024-05-28 01:42:32","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-4487432/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-4487432/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1007/s11069-024-07048-4","type":"published","date":"2024-12-02T15:58:14+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":60308549,"identity":"43867b76-39d3-4c52-8ed1-62c94eb39488","added_by":"auto","created_at":"2024-07-15 12:17:11","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":1151724,"visible":true,"origin":"","legend":"\u003cp\u003eSchematic diagram of self-made vibrating flume tank\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-4487432/v1/9b3a81346e539987ab0e0934.png"},{"id":60309084,"identity":"ad5169ea-6d7a-45df-8fab-8c383a2b240a","added_by":"auto","created_at":"2024-07-15 12:25:12","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":2590158,"visible":true,"origin":"","legend":"\u003cp\u003eMovement phenomenon of the sliding body\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-4487432/v1/0b91725f4a65975e70f34198.png"},{"id":60308551,"identity":"1ffad2c2-fef9-432a-8fb8-430760e868e7","added_by":"auto","created_at":"2024-07-15 12:17:12","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":536209,"visible":true,"origin":"","legend":"\u003cp\u003eSoil erosion and accumulation morphology in the flume\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-4487432/v1/e19486ab7600b715d9742de1.png"},{"id":60309083,"identity":"04471d2f-9da8-4a0e-9b41-ae3787882e79","added_by":"auto","created_at":"2024-07-15 12:25:11","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":72103,"visible":true,"origin":"","legend":"\u003cp\u003eMovement velocity-time relationship curves of the three parallel experiments\u003c/p\u003e","description":"","filename":"4.png","url":"https://assets-eu.researchsquare.com/files/rs-4487432/v1/e718a0ee5d7b5e5dd1d3dc6d.png"},{"id":60308547,"identity":"0df77e37-fdca-44de-86bb-34f9d9874497","added_by":"auto","created_at":"2024-07-15 12:17:11","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":88212,"visible":true,"origin":"","legend":"\u003cp\u003eMovement patterns of the head of the sliding body at different times ( unit: m )\u003c/p\u003e","description":"","filename":"5.png","url":"https://assets-eu.researchsquare.com/files/rs-4487432/v1/70db8eb6a564a196fd55304d.png"},{"id":60309085,"identity":"0a21bec4-1c99-4dc4-bfea-0be660fa0f76","added_by":"auto","created_at":"2024-07-15 12:25:12","extension":"png","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":630861,"visible":true,"origin":"","legend":"\u003cp\u003eStrain-time relationship curves of the three parallel experiments\u003c/p\u003e","description":"","filename":"6.png","url":"https://assets-eu.researchsquare.com/files/rs-4487432/v1/39398fed65ac9dadf5da5b59.png"},{"id":60308556,"identity":"a5f46b5b-8e4b-4a77-aede-5395176b9b02","added_by":"auto","created_at":"2024-07-15 12:17:12","extension":"png","order_by":7,"title":"Figure 7","display":"","copyAsset":false,"role":"figure","size":736393,"visible":true,"origin":"","legend":"\u003cp\u003eMovement contour diagrams of sliding bodies with different clay content\u003c/p\u003e","description":"","filename":"7.png","url":"https://assets-eu.researchsquare.com/files/rs-4487432/v1/7e120aefb3cdc82f910b2c09.png"},{"id":60308552,"identity":"4bd841f3-78f3-4f98-83cd-baf070a853b9","added_by":"auto","created_at":"2024-07-15 12:17:12","extension":"png","order_by":8,"title":"Figure 8","display":"","copyAsset":false,"role":"figure","size":656086,"visible":true,"origin":"","legend":"\u003cp\u003eMovement contour diagrams of sliding bodies with different vibration frequencies\u003c/p\u003e","description":"","filename":"8.png","url":"https://assets-eu.researchsquare.com/files/rs-4487432/v1/2927c2d6b99144279b90b4df.png"},{"id":60309086,"identity":"0ed10584-2634-41af-973b-5a17cfac79e1","added_by":"auto","created_at":"2024-07-15 12:25:12","extension":"png","order_by":9,"title":"Figure 9","display":"","copyAsset":false,"role":"figure","size":613168,"visible":true,"origin":"","legend":"\u003cp\u003eMovement contour diagrams of sliding bodies with different electrolyte concentrations\u003c/p\u003e","description":"","filename":"9.png","url":"https://assets-eu.researchsquare.com/files/rs-4487432/v1/64d0b0e118224d01525d6a7e.png"},{"id":60308554,"identity":"522d3000-3aa6-4f66-9fe5-d29f3a591312","added_by":"auto","created_at":"2024-07-15 12:17:12","extension":"png","order_by":10,"title":"Figure 10","display":"","copyAsset":false,"role":"figure","size":613991,"visible":true,"origin":"","legend":"\u003cp\u003eMovement contour diagrams of sliding bodies with different seabed slope gradients\u003c/p\u003e","description":"","filename":"10.png","url":"https://assets-eu.researchsquare.com/files/rs-4487432/v1/e2a3eae3f191daaa837f8a33.png"},{"id":70964909,"identity":"2bc98090-c324-4b09-b3d4-3e52b27d8699","added_by":"auto","created_at":"2024-12-09 16:17:20","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":13292203,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-4487432/v1/f9fb3647-bce8-44f3-9572-6ce0f960f822.pdf"}],"financialInterests":"","formattedTitle":"Experimental study on movement characteristics and influence factors of submarine landslide triggered by earthquake","fulltext":[{"header":"1 Introduction","content":"\u003cp\u003eSubmarine landslides are phenomena of submarine mud and sand flow triggered by gravity or external loads. They have large scale, high density and high sand content. They can travel along the seabed over long distances at high velocity; they occur widely in continental marginal basins and island slope zones(Wang et al. \u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e2018\u003c/span\u003e; Hampton et al.). Submarine landslides can damage pipelines, tunnels, other underwater facilities(Dai et al. \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e2017\u003c/span\u003e; Dutta and Hawlader \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e2019\u003c/span\u003e), and may also cause secondary disasters such as tsunamis, causing even great economic losses and casualties (Hayir et al. \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e2008\u003c/span\u003e; Corona and Ram\u0026iacute;rez-Herrera \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e2015\u003c/span\u003e; Nakata et al. \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e2020\u003c/span\u003e). In July 1998, a submarine landslide in Papua New Guinea triggered a tsunami. The waves exceeded \u003csup\u003e15 m\u003c/sup\u003e in height \u003csup\u003eand killed more than 2000 people\u003c/sup\u003e(Tappin et al. \u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e2001\u003c/span\u003e). \u003csup\u003eOn 26 December 2006 a submarine landslide occurred in\u003c/sup\u003e the \u003csup\u003eLuzon Strait\u003c/sup\u003e. S\u003csup\u003eubmarine optical cable\u003c/sup\u003es \u003csup\u003ew\u003c/sup\u003eere \u003csup\u003ebroken, and communication between China and Southeast Asian countries was cut for 12h\u003c/sup\u003e (Hsu et al. 2006). \u003csup\u003eIn the context of the accelerated development of marine resources, subsea engineering facilities, such as subsea drilling platforms, communication cables, subsea oil storage tanks, and artificial islands, will increase. Submarine landslides inevitably pose a huge threat to the safety of\u003c/sup\u003e many \u003csup\u003ef\u003c/sup\u003euture offshore and coastal \u003csup\u003eprojects\u003c/sup\u003e\u003c/p\u003e \u003cp\u003e(Masson et al. \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e2006\u003c/span\u003e; Poupardin et al. \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e2020\u003c/span\u003e). Therefore, the study of the movement characteristics of submarine landslides can help to understand this natural phenomenon in depth and provide a basis for evaluating the hazards, which is of great significance in preventing and avoiding future disasters.\u003c/p\u003e \u003cp\u003eThe research methods for submarine landslides include physical model experiments (the lab based investigations), theoretical models, and numerical simulations. Owing to the limitations of environmental and technical conditions, it is difficult to directly observe the destruction process of submarine slopes. Therefore, physical model experiments remain an effective method for studying submarine landslides. SCHWARZ(1982) conducted an earlier flume experiment to study the deposition rate and thickness of submarine landslides, and Ataie-Ashtiani and Najafi-Jilani (\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2008\u003c/span\u003e) conducted 120 sets of experiments to study the waves generated by submarine landslides and obtained very useful data. Zakeri et al. (\u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e2008\u003c/span\u003e) gave a new definition of the Reynolds number and proposed a method for estimating the drag forces upon impact with submarine debris flows normal to the pipeline axis. Elverhoi et al. (\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e2010\u003c/span\u003e) studied the movement state of submarine landslides with different clay content. The results indicated that the sliding body produced a layered movement phenomenon when the clay content was low. Sequeiros (\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e2012\u003c/span\u003e) conducted indoor experiments and obtained the flow conditions of gravity flow. An et al (\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e2016\u003c/span\u003e) studied the influence of the clay content of the sliding body on the deposition process of a submarine landslide. Takahashi et al. (\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e2020\u003c/span\u003e) used centrifuge simulation experiments to provide insights into the initiation mechanism of sandy and silty submarine landslides and their flow and depositional characteristics under seismic and liquefaction effects. Carey et al. (\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e2019\u003c/span\u003e; 2022) based on dynamic backpressure shear box experiments, found that landslides may undergo cyclic sliding under prolonged high-amplitude ground shaking, and elucidated the effects of pore water pressure and dynamic stress changes on slow landslide displacements. S\u0026oslash;rlie (\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e2023\u003c/span\u003e) did 21 physical model tests to study the velocity, migration distance and impact force of clay-rich submarine landslides on foundation columns. Silver (\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e2023\u003c/span\u003e) through flume experiments, found that non-tsunamigenic submarine slope failures can be induced under overpressure conditions in low-permeability, high-cohesion sediments.\u003c/p\u003e \u003cp\u003eIn terms of theoretical model research, Pudasaini (\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e2012\u003c/span\u003e) proposed a generalised two-phase debris flow model that can better describe the complex dynamics of submarine landslides and related phenomena. Buss et al. (\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e2019\u003c/span\u003e) proposed a formation and evolution process of submarine landslides based on the kinematic balance method. In numerical simulations, Liu (\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e2015\u003c/span\u003e) used computational fluid dynamics (CFD) to study the impact force of submarine landslides on offshore pipelines and established empirical formulas for estimating normal and axial impact forces, while An et al. (\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e2016\u003c/span\u003e) used smoothed-particle hydrodynamics (SPH) to simulate the evolution process of submarine landslides and found that the sliding body was strongly deformed during the impact. Mao et al. (\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e2020\u003c/span\u003e) proposed a new discrete element method for solving CFD, which can more accurately simulate the interaction between fluid fields in the process of submarine landslides. Wu et al. (\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e2023\u003c/span\u003e) proposed a CFD-DEM method considering the influence of non-spherical particles, analyzed the influence of particles on the process of submarine landslide collapse, and explored the process and characteristics of soil particles filling with water.\u003c/p\u003e \u003cp\u003eDespite these advances, physical model experiments (the lab based investigations) remain the main method for studying submarine landslides. In physical model experiments, researchers mostly use mud dumping into a quiet water environment to simulate landslides, ignoring the formation conditions of submarine landslides and ocean hydrodynamic factors. Scholars have mostly conducted research on the movement state of landslides, but few studies have systematically and comprehensively summarized the movement characteristics of submarine landslides.\u003c/p\u003e \u003cp\u003eIn this study, a novel vibrating flume tank was constructed to comprehensively study the movement characteristics of submarine landslides triggered by earthquakes. It studies the macroscopic phenomena of submarine landslide triggered by earthquake, analyzes the velocity variation of landslide, and the stress of slope structures in different positions during landslide movement. And also, the influence of clay content of landslide, seismic vibration frequency, electrolyte concentration in seawater and submarine slope on the migration characteristics of submarine landslide is studied. The results of this study will make us further understand the characteristics of submarine landslides, and is of great significance to the construction and protection of marine engineering facilities.\u003c/p\u003e"},{"header":"2 Methods","content":"\u003cdiv id=\"Sec3\"\u003e\n \u003ch2\u003e2.1 Equipment and materials\u003c/h2\u003e\n \u003cp\u003eA scale model experiment was used in this research. The ratio of similitude was calculated using dimensional analysis, as shown in Table\u0026nbsp;\u003cspan\u003e1\u003c/span\u003e. In flume experiments, scholars have widely used mudflow to simulate a sliding body. Mudflow is made by mixing kaolin, silt, and water in a certain proportion(Ilstad et al. \u003cspan\u003e2004\u003c/span\u003e; Cai et al. \u003cspan\u003e2018\u003c/span\u003e). Therefore, the experimental sliding body was configured based on previous research and experience. The sliding body was configured according to the particle size distribution range of the offshore seabed soil listed in Table\u0026nbsp;\u003cspan\u003e2\u003c/span\u003e and the experimental requirements(Bornhold et al. \u003cspan\u003e1986\u003c/span\u003e; Yang \u003cspan\u003e1987\u003c/span\u003e; Saito et al. \u003cspan\u003e2001\u003c/span\u003e).\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003eTable 1\u003c/strong\u003e Similarity ratio of model simulation experiment\u003c/p\u003e\n \u003cdiv\u003e\n \u003cdiv align=\"left\"\u003e\u003cimg src=\"https://myfiles.space/user_files/122228_c8a1650c59388082/122228_custom_files/img1721045509.png\"\u003e\u003cbr\u003e\u003c/div\u003e\n \u003c/div\u003e\n \u003cdiv\u003e\n \u003ctable id=\"Tab2\" border=\"1\"\u003e\n \u003ccaption language=\"En\"\u003e\n \u003cdiv\u003eTable 2\u003c/div\u003e\n \u003cdiv\u003e\n \u003cp\u003eThe particle size distribution of offshore seabed soil\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003ccolgroup cols=\"3\"\u003e\u003c/colgroup\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eParticle size grade\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eParticle diameter (mm)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eContent(%)\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eCoarse particle\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.25\u0026thinsp;\u0026minus;\u0026thinsp;0.075\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e40\u0026ndash;60\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePowder particle\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e0.075\u0026thinsp;\u0026minus;\u0026thinsp;0.005\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e20\u0026ndash;40\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eClay particles\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u0026lt;\u0026thinsp;0.005\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u0026lt;\u0026thinsp;30\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n \u003c/div\u003e\n \u003cp\u003eThe internal dimensions of the flume were 2.4m long, 0.3m wide and 1.2m high. A vibrating tank was set up to simulate the earthquake source region and avoid the boundary effect caused by the overall vibration of the flume. The internal dimensions of the vibrating tank were 0.4m long, 0.3m wide and 0.4m high. An outer tank was connected to the flume and the vibration tank. The internal dimensions of the outer tank were 0.5m long, 0.4m wide and 0.5m high. A removable baffle was set between the vibrating tank and flume. A schematic of the equipment is shown in Fig.\u0026nbsp;\u003cspan\u003e1\u003c/span\u003e.\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec4\"\u003e\n \u003ch2\u003e2.2 Experiment process\u003c/h2\u003e\n \u003cp\u003eA seabed slope was constructed in a flume to simulate the initial terrain conditions. The seabed slope height was 0.7 meters. The seabed slope gradient was modified according to different experimental requirements. The remaining part on the left side of the flume (refer to Fig.\u0026nbsp;\u003cspan\u003e1\u003c/span\u003e(c)) was the horizontal accumulation area. The horizontal accumulation area was laid with fine sand. Silty sand with a height of 20 cm, length of 40 cm, and width of 30 cm was placed in the vibrating tank to simulate a sliding body in the source region.\u003c/p\u003e\n \u003cp\u003eTo analyse the force of the sliding seabed, soil pressure sensors T-1, T-2, and T-3 were arranged at a height of 1\u0026ndash;2 cm from the surface of the seabed slope (refer to Fig.\u0026nbsp;\u003cspan\u003e1\u003c/span\u003e(c). The horizontal distances between the three soil pressure sensors and the top of the seabed slope were 30, 90, and 150 cm, respectively. To monitor the pore water pressure changes in the sliding body and determine the start time of the sliding body movement, a pore water pressure sensor was buried at a depth of 10 cm inside the sliding body in the source region. After the sensors were arranged, water was slowly poured into the flume so that the water levels in both the flume and the vibrating tank were level. The height of the water injection was 1m.\u003c/p\u003e\n \u003cp\u003eWhen the sliding body liquefied under the action of the seismic load, it began to slide. To determine the time at which the sliding body started to slide down in the experiment, the strain value when the sliding body liquefies was calculated prior to the experiment. When the sand was completely liquefied, the pore water pressure measured by the pore water pressure sensor was the total stress. The experiment showed that the saturated unit weight of sand was 18.7kN/m\u003csup\u003e3\u003c/sup\u003e, and the total stress was 3.87kPa. The calibration coefficient of the pore-water pressure sensor was 0.02706. The calculated strain value of sliding-body liquefaction was 143\u0026micro;\u0026epsilon;.\u003c/p\u003e\n \u003cp\u003eIn the experiment, the switch button of the motor was adjusted to grades 1\u0026ndash;8 according to the requirements. The vibrating tank was operated at a vibration frequency of 1\u0026ndash;8 Hz and vibration amplitude of 2 cm. The magnitude of the vibration frequency represented the simulated seismic frequency in the experiment. The change in the strain value of the pore-water pressure sensor in the tank was monitored using a strain gauge. When the strain value reached 143\u0026micro;\u0026epsilon;, the sliding body liquefied. At this time, the baffle of the vibrating tank was pulled away, and the landslide soil body began to slide downward under the action of vibration load and gravity. The change in the soil pressure sensor value was monitored during the experiment, and the macroscopic phenomenon in the flume was photographed using a high-speed camera. After the experiment, the flume was rested for 2\u0026ndash;3 h to precipitate the suspended soil particles. Morphological changes in the seabed slope and the accumulation form of the landslide soil after the landslide flow were observed.\u003c/p\u003e\n\u003c/div\u003e"},{"header":"3 Results and discussion","content":"\u003cp\u003eIn the experiment, the clay content of the sliding body, earthquake vibration frequency, electrolyte concentration, and seabed slope gradient were controlled separately. Multiple sets of experiments were conducted to determine the movement characteristics of a submarine landslide triggered by an earthquake. This section describes one set of experiments as an example (the seabed slope gradient was 20\u0026deg;, the clay content of the sliding body was 20%, the earthquake vibration frequency was 3 Hz, and no electrolyte was added to the water) to illustrate the movement characteristics of submarine landslides triggered by earthquakes. The forces of the seabed slope structures at different locations in the process of submarine landslides were analysed.\u003c/p\u003e \u003cdiv id=\"Sec6\" class=\"Section2\"\u003e \u003ch2\u003e3.1 Movement characteristics\u003c/h2\u003e \u003cdiv id=\"Sec7\" class=\"Section3\"\u003e \u003ch2\u003e3.1.1 Macroscopic phenomenon\u003c/h2\u003e \u003cp\u003eAfter the sand in the vibrating tank was liquefied, the baffle at the connection between the vibrating tank and flume was pulled out, and the liquefied sand in the vibrating tank flowed out, sliding on the prefabricated seabed slope, and forming a landslide. The experimental process is illustrated in Fig .2.\u003c/p\u003e \u003cp\u003eIn terms of the movement process, the head of the sliding body was high and steep, the middle section was conical, and the water content of the tail was high. With erosion occurring in the process of movement and mixing of water, particle dispersion occurred in the sliding body. For fine particles, because the upward buoyancy provided by the pore water pressure was greater than gravity, fine particles moved upward. For coarse particles, because gravity was greater than buoyancy, the coarse particles remained in the sliding body and continued to move. Therefore, overall, the upper soil layer of the sliding body was loose, forming the low-density flow, and the boundary line of the low-density flow was in the shape of a wave bending in the opposite direction of movement, while the coarse particles in the sliding body were constantly concentrated, forming the high-density flow.\u003c/p\u003e \u003cp\u003eThe surfaces of the seabed slope and horizontal accumulation area were observed after the experiment. Soil erosion and sedimentation in the flume are shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e3\u003c/span\u003e. The seabed slope surface was uneven and contained gullies. This was because the surface of the slope was eroded during the sliding body movement, and at the same time, soil particles continued to deposit. In the horizontal accumulation area, the gullies were not obvious, and the soil was significantly thicker than before the experiment. This was because the horizontal accumulation area was dominated by sedimentation, the particle size of the lower layer of the sedimentary layer was coarse, the particle size of the upper layer was fine, and the entire layer was stacked.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec8\" class=\"Section3\"\u003e \u003ch2\u003e3.1.2 Velocity research\u003c/h2\u003e \u003cp\u003eThe experiment was repeated three times to reduce the possibility of errors in the experiment. CAD was used to draw the contour line of the sliding body at each moment in the flume (recorded from 2s, with an interval of 1s). Sliding body movement velocities were calculated based on the contour line. The movement velocity-time relationship curves of the three parallel experiments are shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e4\u003c/span\u003e.\u003c/p\u003e \u003cp\u003eBy analyzing the movement velocity-time relationship curves of the sliding body and the movement pattern of the head of the sliding body at different times \u003cb\u003e(\u003c/b\u003eFig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e5\u003c/span\u003e\u003cb\u003e)\u003c/b\u003e, it can be concluded that the velocity of the sliding body was not uniform during the movement. The movement of a sliding body has the characteristics of periodic and intermittent flow. In the first 3s of movement, the movement velocity was high under the action of gravity owing to the large amount of material in the sliding body. At approximately 4s, the velocity of the sliding body reached its maximum value. Subsequently, owing to the resistance of the seabed slope surface, some soil particles were deposited, and the kinetic energy was rapidly reduced; thus, the velocity of the sliding body was greatly reduced. From 5s to 6s, the slope of the head of the sliding body became steeper, indicating that the soil particles at the head were gathering, and the velocity increased gradually owing to the resistance along the way. At approximately 6s, the head of the sliding body experienced critical failure, the sliding body velocity reached its peak, and then the velocity decreased rapidly. Between 8 and 10s, the particles in the head of the sliding body continuously accumulated, and the movement velocity of the sliding body increased. At approximately 10 s, the head of the sliding body collapsed and the velocity reached its peak. Subsequently, the velocity of the sliding body decreased and then gradually increased after 11s. The sliding body moved to the horizontal area in 14s, and then the movement velocity decreased gradually owing to the influence of the resistance.\u003c/p\u003e \u003cp\u003eThe reasons for this process are as follows. During the movement of the sliding body, the coarse particles are continuously concentrated in the head. When the driving force behind the sliding body is insufficient to promote head movement, the head movement velocity decreases, and the particles behind the head are continuously transported to the head by water, which leads to the expansion of the head of the sliding body and an increase in slope declination. The movement of the sliding body has periodicity, and each period can be decomposed into the following three stages. In the first stage, the rear driving force of the sliding body is insufficient, resulting in a decline in the movement velocity, and the rear soil particles continue to accumulate in the head. In the second stage, with the accumulation of soil particles, the front slope of the sliding body head increases, forming an additional slope declination. In the third stage, after the sliding body head reaches the additional slope declination of the critical failure, the head collapses, and the velocity of the sliding body increases.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec9\" class=\"Section3\"\u003e \u003ch2\u003e3.1.3 Force analysis\u003c/h2\u003e \u003cp\u003eThe values of the soil pressure sensors above the seabed slope can reflect the force of the seabed slope structures at different positions during the sliding body movement. Before the experiment, the strain values of the T-1, T-2, and T-3 soil pressure sensors were monitored with time under hydrostatic pressure for 10s. The values are listed in Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eStrain value of sensor in 10s under hydrostatic pressure (\u0026times;10\u003csup\u003e\u0026minus;\u0026thinsp;6\u003c/sup\u003e)\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTime(s)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eT-1\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eT-2\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eT-3\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e136\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e207\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e292\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e138\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e210\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e295\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e144\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e208\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e297\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e138\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e212\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e293\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e142\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e210\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e290\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e141\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e204\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e288\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e145\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e202\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e291\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e146\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e199\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e293\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e148\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e198\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e297\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e142\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e200\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e294\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eIt can be seen from Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e that the strain values produced by the water pressure changed within a certain range, which might be caused by the sensor's own error or the slight disturbance of water. The average strain values of sensors T-1, T-2, and T-3 in quiet water were 142\u0026times;10\u003csup\u003e\u0026minus;\u0026thinsp;6\u003c/sup\u003e, 205\u0026times;10\u003csup\u003e\u0026minus;\u0026thinsp;6\u003c/sup\u003e, and 293\u0026times;10\u003csup\u003e\u0026minus;\u0026thinsp;6\u003c/sup\u003e, respectively. The calibration coefficients of the three sensors were 0.02706, 0.02694, and 0.02726, respectively. Therefore, the pressures measured by the three sensors were 3.8 kPa, 5.5 kPa, and 8.0 kPa, respectively. The distances from the centre of the circular sensor sheets of the T-1, T-2, and T-3 sensors to the water surface were 41, 62, and 86 cm, respectively, and the actual water pressures generated at each height were 4.1kPa, 6.2kPa, and 8.6kPa. The errors were not significantly different, and the results were still of research significance.\u003c/p\u003e \u003cp\u003eIn the experiment, the strain value of the soil pressure sensor minus the average strain value under hydrostatic pressure were used to obtain the strain value of the seabed slope structures at different positions at each moment of the sliding body movement. The strain-time relationship curves for the three sets of parallel experiments are shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig7\" class=\"InternalRef\"\u003e6\u003c/span\u003e.\u003c/p\u003e \u003cp\u003eAccording to Fig.\u0026nbsp;\u003cspan refid=\"Fig7\" class=\"InternalRef\"\u003e6\u003c/span\u003e, the influence of the sliding body and vibration load on the seabed slope structure was not obvious at the beginning of the movement. With the downward movement of the sliding body, the force on the structure strengthened, and the strain of the structure gradually increased. When the sliding body moved to the position of the slope structure, the strain in the structure changed abruptly and reached a peak value. Then, the head of the sliding body moved forward, the structure was still affected by the impact of the particles inside the sliding body, and the impact force fluctuated near the peak. After most of the sliding body passed through the structure, it was still impacted by the residual flowing sand. Simultaneously, the strain gradually decreased and finally stabilized.\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv id=\"Sec10\" class=\"Section2\"\u003e \u003ch2\u003e3.2 Influence factors on the movement characteristics\u003c/h2\u003e \u003cp\u003eIn this section, the factors influencing the movement characteristics of submarine landslides, such as the clay content of the sliding body, earthquake vibration frequency, electrolyte concentration in seawater, and seabed slope gradient are discussed.\u003c/p\u003e \u003cdiv id=\"Sec11\" class=\"Section3\"\u003e \u003ch2\u003e3.2.1 Clay content\u003c/h2\u003e \u003cp\u003eThe experimental conditions were as follows: the seabed slope gradient was 20\u0026deg;, earthquake vibration frequency was 3 Hz, no electrolyte was added to the water, no glass plates were laid on the seabed slope surface, and the clay content of the sliding body was changed to 5%, 10%, and 15%. Three sets of parallel experiments were conducted to reduce the possibility of errors in the experiment. The movement contour diagrams of the sliding body at 5s, 10s, and 15s in the three sets of experiments are shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig8\" class=\"InternalRef\"\u003e7\u003c/span\u003e.\u003c/p\u003e \u003cp\u003eThe movement contour diagrams show that at each observed time, the horizontal migration distance of the sliding body decreased with an increase in clay content. The average velocities of the sliding bodies in the three sets of experiments were 18.3 cm/s, 15.2 cm/s, 12.3 cm/s respectively, and the average velocities of movement in the horizontal accumulation area were 16.0 cm/s, 15.1 cm/s, 12.5 cm/s respectively. This is because the hydration of clay particles reduced the free water in the soil and weakened the lubrication between particles; thus, the plastic flow deformation of the sliding body was enhanced, and the friction force increased, consequently the movement velocity was reduced.\u003c/p\u003e \u003cp\u003eIn repeated experiments, glass plates were laid on the seabed slope surface to study the accumulation characteristics of submarine landslides. The results are presented in Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab4\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eAccumulation of submarine landslide soil at different clay content\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"9\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c9\" colnum=\"9\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eClay content\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003eHorizontal zone\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c5\" namest=\"c4\"\u003e \u003cp\u003eSeabed slope\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c7\" namest=\"c6\"\u003e \u003cp\u003eSource region\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c9\" namest=\"c8\"\u003e \u003cp\u003eTotal\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eSoil amount\u003c/p\u003e \u003cp\u003e(kg)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eProportion\u003c/p\u003e \u003cp\u003e(%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eSoil amount\u003c/p\u003e \u003cp\u003e(kg)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eProportion\u003c/p\u003e \u003cp\u003e(%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eSoil amount\u003c/p\u003e \u003cp\u003e(kg)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003eProportion\u003c/p\u003e \u003cp\u003e(%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c8\"\u003e \u003cp\u003eSoil amount\u003c/p\u003e \u003cp\u003e(kg)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c9\"\u003e \u003cp\u003eProportion(%)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e5%\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e7.63\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e30.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e6.77\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e26.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e10.95\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e43.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e25.35\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e10%\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e8.10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e32.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e6.66\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e26.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e10.09\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e40.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e24.85\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e15%\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e9.81\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e36.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e7.53\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e28.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e9.28\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e34.9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e26.62\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eThe results show that when the clay content of the sliding body was higher, more soil particles accumulated in the seabed slope and horizontal accumulation area. This was because, as the clay particle content increased, the soil particles become denser, and the interaction between particles was strengthened. Therefore, the erosion and deposition during the movement of the sliding body were strengthened, and the movement velocity decreased.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec12\" class=\"Section3\"\u003e \u003ch2\u003e3.2.2 Vibration Frequency\u003c/h2\u003e \u003cp\u003eThe experimental conditions were as follows: the clay content of the sliding body was 10%, the seabed slope gradient was 20\u0026deg;, no electrolyte was added to the water, no glass plates were laid on the seabed slope surface, and the earthquake vibration frequency was changed to 2 Hz, 3 Hz, and 4 Hz. Three sets of parallel experiments were conducted to reduce the possibility of errors in the experiment. The movement contour diagrams of the sliding body at 5s, 10s, and 15s in the three sets of experiments are shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig9\" class=\"InternalRef\"\u003e8\u003c/span\u003e.\u003c/p\u003e \u003cp\u003eThe movement contour diagrams show that at each observed time the horizontal movement distance of the sliding body increased with an increase in the seismic vibration frequency. The average velocities of the sliding bodies in the three sets of experiments were 15.2 cm/s, 14.1 cm/s, 17.5 cm/s respectively, and the average velocities of movement in the horizontal accumulation area were 14.5 cm/s, 13.8 cm/s, 16.1 cm/s respectively. These data show that the average movement velocity of the sliding body increased with an increase in the vibration frequency. This was because with an increase in vibration frequency, the mass of the sliding body in liquefaction in the source region increased. In addition, with an increase in vibration frequency, the diffusion of clay particles at the source region became greater, and the floating of large soil particles increased the density of the low-density layer of the landslide.\u003c/p\u003e \u003cp\u003eIn repeated experiments, glass plates were laid on the seabed slope surface to study the accumulation characteristics of submarine landslides. The results are presented in Table\u0026nbsp;\u003cspan refid=\"Tab5\" class=\"InternalRef\"\u003e5\u003c/span\u003e.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab5\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 5\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eAccumulation of submarine landslide soil at different vibration frequency\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"9\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c9\" colnum=\"9\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eVibration\u003c/p\u003e \u003cp\u003efrequency\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003eHorizontal zone\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c5\" namest=\"c4\"\u003e \u003cp\u003eSeabed slope\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c7\" namest=\"c6\"\u003e \u003cp\u003eSource region\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c9\" namest=\"c8\"\u003e \u003cp\u003eTotal\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eSoil amount\u003c/p\u003e \u003cp\u003e(kg)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eProportion\u003c/p\u003e \u003cp\u003e(%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eSoil amount\u003c/p\u003e \u003cp\u003e(kg)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eProportion\u003c/p\u003e \u003cp\u003e(%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eSoil amount\u003c/p\u003e \u003cp\u003e(kg)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003eProportion\u003c/p\u003e \u003cp\u003e(%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c8\"\u003e \u003cp\u003eSoil amount\u003c/p\u003e \u003cp\u003e(kg)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c9\"\u003e \u003cp\u003eProportion\u003c/p\u003e \u003cp\u003e(%)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e2Hz\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e5.73\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e22.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e5.71\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e22.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e13.69\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e54.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e25.13\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e3Hz\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e8.10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e32.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e6.66\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e26.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e10.09\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e40.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e24.85\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e4Hz\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e7.72\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e34.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e6.82\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e30.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e7.91\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e35.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e22.45\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eIt can be observed from the results that with an increase in the vibration frequency, the sliding body is more likely to lose stability. This is because the vibration frequency increased the degree of liquefaction of the sliding body in the seabed slope, and the quality of the sliding soil increased.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec13\" class=\"Section3\"\u003e \u003ch2\u003e3.2.3 Electrolyte concentration\u003c/h2\u003e \u003cp\u003eThe concentration of electrolyte in seawater is approximately 3.6 g/L, of which Na\u003csup\u003e+\u003c/sup\u003e, Cl\u003csup\u003e\u0026minus;\u003c/sup\u003e, and Mg\u003csup\u003e2+\u003c/sup\u003e have the highest content. NaCl accounts for more than 80% of the total mass. Therefore, NaCl and a small amount of MgCl\u003csup\u003e2\u003c/sup\u003e were selected as research variables in the experiment. The experimental conditions were as follows: the clay content of the sliding body was 10%; the seabed slope gradient was 20\u0026deg;; the earthquake vibration frequency was 3 Hz; no glass plates were laid on the seabed slope surface; and the electrolyte concentration in the water was changed to 0, 3.6 g/L, and 7.2 g/L. Three sets of parallel experiments were conducted to reduce the possibility of errors in the experiment. The movement contour diagrams of the sliding body at 5s, 10s, and 15s in the three sets of experiments are shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig10\" class=\"InternalRef\"\u003e9\u003c/span\u003e.\u003c/p\u003e \u003cp\u003eThe movement contour diagrams show that at each observed time the horizontal movement distance of the sliding body increased with an increase in the electrolyte concentration. The average velocities of the sliding bodies in the three sets of experiments were 15.2 cm/s, 15.9 cm/s, 17.9 cm/s respectively, and the average velocities of movement in the horizontal accumulation area were 14.5 cm/s, 14.5 cm/s, 16.4 cm/s respectively. This was because the electrolyte in the seawater increased the water pressure and sliding force of the sliding body. In addition, the electrolyte had a lubricating effect and reduced the resistance of the sliding body.\u003c/p\u003e \u003cp\u003eIn repeated experiments, glass plates were laid on the seabed slope surface to study the accumulation characteristics of submarine landslides. The results are presented in Table\u0026nbsp;\u003cspan refid=\"Tab6\" class=\"InternalRef\"\u003e6\u003c/span\u003e.It can be seen from the results that the mass of the sliding body decreased with an increase in the electrolyte concentration. This was because the lubrication of the electrolyte made it difficult for the soil particles to deposit on the seabed slope, and the lubrication also weakened the interaction between the soil particles. Therefore, the liquefaction of the sliding body did not occur easily, and the quality of the sliding soil was reduced.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab6\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 6\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eAccumulation of submarine landslide soil with different electrolyte concentrations\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"9\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c9\" colnum=\"9\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eElectrolyte\u003c/p\u003e \u003cp\u003econcentration\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003eHorizontal zone\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c5\" namest=\"c4\"\u003e \u003cp\u003eSeabed slope\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c7\" namest=\"c6\"\u003e \u003cp\u003eSource region\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c9\" namest=\"c8\"\u003e \u003cp\u003eTotal\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eSoil amount\u003c/p\u003e \u003cp\u003e(kg)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eProportion\u003c/p\u003e \u003cp\u003e(%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eSoil amount\u003c/p\u003e \u003cp\u003e(kg)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eProportion\u003c/p\u003e \u003cp\u003e(%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eSoil amount\u003c/p\u003e \u003cp\u003e(kg)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003eProportion\u003c/p\u003e \u003cp\u003e(%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c8\"\u003e \u003cp\u003eSoil amount\u003c/p\u003e \u003cp\u003e(kg)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c9\"\u003e \u003cp\u003eProportion\u003c/p\u003e \u003cp\u003e(%)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e8.10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e32.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e6.66\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e26.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e10.09\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e40.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e24.85\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e3.6g/L\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e9.69\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e35.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e6.22\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e22.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e11.72\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e42.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e27.63\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e7.2g/L\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e8.85\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e34.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e5.32\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e20.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e11.87\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e45.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e26.04\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec14\" class=\"Section3\"\u003e \u003ch2\u003e3.2.4 Seabed slope gradient\u003c/h2\u003e \u003cp\u003eThe experimental conditions were as follows: the clay content of the sliding body was 10%, the earthquake vibration frequency was 3 Hz, no electrolyte was added to the water, no glass plates were laid on the seabed slope surface, and the seabed slope gradient was changed to 30\u0026deg;, 20\u0026deg;, and 10\u0026deg;. Three sets of parallel experiments were conducted to reduce the possibility of errors in the experiment. The movement contour diagrams of the sliding body at 5s, 10s, and 15s in the three sets of experiments are shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig11\" class=\"InternalRef\"\u003e10\u003c/span\u003e.\u003c/p\u003e \u003cp\u003eThe movement contour diagrams show that at each observed time, the horizontal movement distance of the sliding body increased with an increase in the seabed slope gradient. The average velocities of the sliding bodies in the three sets of experiments were 15.9 cm/s, 15.2 cm/s, 14.1 cm/s respectively. This was because, when the seabed slope gradient increased, the soil particles in the sliding body were not easily deposited on the seabed slope surface under the influence of gravity. The movement of the sliding body was intense, and the erosion on the seabed slope surface was increased. Thus, the volume of the sliding body increased, and the movement velocity increased.\u003c/p\u003e \u003cp\u003eIn repeated experiments, glass plates were laid on the seabed slope surface to study the accumulation characteristics of submarine landslides. The results are presented in Table\u0026nbsp;\u003cspan refid=\"Tab7\" class=\"InternalRef\"\u003e7\u003c/span\u003e.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab7\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 7\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eAccumulation of submarine landslide soil at different seabed slope gradients\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"9\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c9\" colnum=\"9\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eSeabed slope gradient\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003eHorizontal zone\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c5\" namest=\"c4\"\u003e \u003cp\u003eSeabed slope\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c7\" namest=\"c6\"\u003e \u003cp\u003eSource region\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c9\" namest=\"c8\"\u003e \u003cp\u003eTotal\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eSoil amount\u003c/p\u003e \u003cp\u003e(kg)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eProportion\u003c/p\u003e \u003cp\u003e(%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eSoil amount\u003c/p\u003e \u003cp\u003e(kg)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eProportion\u003c/p\u003e \u003cp\u003e(%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eSoil amount\u003c/p\u003e \u003cp\u003e(kg)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003eProportion\u003c/p\u003e \u003cp\u003e(%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c8\"\u003e \u003cp\u003eSoil amount\u003c/p\u003e \u003cp\u003e(kg)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c9\"\u003e \u003cp\u003eProportion\u003c/p\u003e \u003cp\u003e(%)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e30\u0026deg;\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e8.10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e32.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e6.66\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e26.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e10.09\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e40.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e24.85\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e20\u0026deg;\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e9.82\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e38.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e5.05\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e19.9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e10.51\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e41.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e25.38\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e10\u0026deg;\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e5.21\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e24.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e7.13\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e32.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e10.82\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e42.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e23.16\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eIt can be seen from the experimental results that when the seabed slope gradient was 30\u0026deg; or 20\u0026deg;, the amount of accumulated soil on the seabed slope was smaller than that in the horizontal accumulation area. When the seabed slope gradient was 10\u0026deg;, the amount of soil accumulated on the seabed slope was greater than that in the horizontal accumulation area. With a decrease in the seabed slope gradient, the sliding body was prone to deposition\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e"},{"header":"4 Conclusions","content":"\u003cp\u003eThis study used a novel vibrating flume tank to study the macroscopic phenomenon of the movement of submarine landslides triggered by earthquakes. The movement velocity of the sliding body and force of the seabed slope structures at different positions were analyzed. The factors influencing the movement characteristics of submarine landslides, including the clay content of the sliding body, earthquake vibration frequency, electrolyte concentration in seawater, and seabed slope gradient were discussed. The conclusions are as follows.\u003c/p\u003e \u003cp\u003eDuring the movement, the head of the sliding body was high and steep, the middle part was conical, and the water content of the tail was high. With erosion in the process of movement and the mixing of water, the sliding body was divided into high-density and low-density flows. The low-density flow in the upper layer produced a wave shape opposite to the direction of motion at the water-soil interface owing to the uneven velocity. The surface of the seabed slope was dominated by erosion, a large number of gullies were formed. The particle size of the lower sedimentary layer was coarse, the upper particle size was fine, and the entire layer was stacked.\u003c/p\u003e \u003cp\u003eThe movement of a sliding body has the characteristics of periodic and intermittent flow. When the sliding body impacts the structure, the force of the structure rapidly reaches its peak, and then the impact force fluctuates around the peak for a period of time and then decreases rapidly.\u003c/p\u003e \u003cp\u003eIn the hazard assessment of submarine landslides, the clay content of the sliding body, electrolyte concentration in the surrounding seawater, and seabed slope gradient should be considered. The plastic deformation of the sliding body with a high clay content is evident. The electrolyte in seawater increases the water pressure and plays the role of a lubricant. Therefore, the sliding body moved faster at high electrolyte concentrations. When the seabed slope gradient increased, the erosion of the sliding body on the seabed slope was enhanced, which increased the volume of the sliding body and accelerated the movement velocity. In addition, the earthquake vibration frequency affected the size and movement of the sliding body. The increase in earthquake vibration frequency makes it easier for landslides to occur and makes the movement velocity of the sliding body faster.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003eAcknowledgment：The authors would like to thank the reviewers who helped modify the language and provided valuable comments, and also thank Weilong Zhang and Shaolong Zhang who helped to do the experiment.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003eThis work was supported by the National Science Foundation of China (Grant No. 41502322), and Science and technology development project of Jilin Province, China (Grant No. 20220101166JC).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor Contributions\u0026nbsp;\u003c/strong\u003eAll authors have contributed to the conception and design of the study. Material preparation, test operation, data collection, and analysis were conducted by YueLou Cai and Shuai Cai. The first draft of the manuscript was written by Min Zhang and Shuai Cai. Writing - review and editing were performed by Min Zhang. The validation was performed by Shiwei Shen and Shulin Dai. Project administration was managed by Yan Xu. All authors have read and approved the final manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConflict of interest\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003eThe author declares that they have no confict of interest.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthical approval\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003eThe study did not involve any human or animal experiments.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eAn Y, Shi CQ, Liu QQ, Yang SH (2016) Study on post-failure evolution of underwater landslide with SPH method In The 7th International Conference on Computational Methods (ICCM2016).\u003c/li\u003e\n\u003cli\u003eAtaie-Ashtiani B, Najafi-Jilani A (2008) Laboratory investigations on impulsive waves caused by underwater landslide. Coastal Engineering, 55(12), 989-1004.\u003c/li\u003e\n\u003cli\u003eBornhold BD, Yang Z-S, Keller GH, et al (1986) Sedimentary framework of the modern Huanghe (Yellow River) delta. Geo-Mar Lett 6:77\u0026ndash;83. https://doi.org/10.1007/BF02281643\u003c/li\u003e\n\u003cli\u003eBuss C, Friedli B, Puzrin AM (2019) Kinematic energy balance approach to submarine landslide evolution. Canadian Geotechnical Journal, 56(9), 1351-1365.\u003c/li\u003e\n\u003cli\u003eCai Y, Nie L, Zhang M, et al (2018) Analysis of the Motion and Dynamic Characteristics of Subaqueous Debris Flows. EKOLOJI 27:1\u0026ndash;7\u003c/li\u003e\n\u003cli\u003eCarey JM (2022) Episodic movement of a submarine landslide complex driven by dynamic loading during earthquakes. Geomorphology, 2022, 408: 108247.\u003c/li\u003e\n\u003cli\u003eCarey JM, Massey CI, Lyndsell B, Petley DN (2019) Displacement mechanisms of slow-moving landslides in response to changes in porewater pressure and dynamic stress. Earth Surf Dyn 7:707\u0026ndash;722. https://doi.org/10.5194/esurf-7-707-2019\u003c/li\u003e\n\u003cli\u003eCorona N, Ram\u0026iacute;rez-Herrera M-T (2015) Did an underwater landslide trigger the June 22, 1932 tsunami off the Pacific coast of Mexico? Pure Appl Geophys 172:3573\u0026ndash;3587. https://doi.org/10.1007/s00024-015-1171-1\u003c/li\u003e\n\u003cli\u003eDai Z, Wang F, Nakahara Y (2017) Experimental Study on Impact Behavior of Submarine Landslides on Communication Cables. In: Advancing Culture of Living with Landslides. Springer, Cham, pp 617\u0026ndash;622\u003c/li\u003e\n\u003cli\u003eDutta S, Hawlader B (2019) Pipeline\u0026ndash;soil\u0026ndash;water interaction modelling for submarine landslide impact on suspended offshore pipelines. G\u0026eacute;otechnique 69:29\u0026ndash;41. https://doi.org/10.1680/jgeot.17.P.084\u003c/li\u003e\n\u003cli\u003eElverhoi A, Breien H, De Blasio FV, et al (2010) Submarine landslides and the importance of the initial sediment composition for run-out length and final deposit. Ocean Dyn 60:1027\u0026ndash;1046. https://doi.org/10.1007/s10236-010-0317-z\u003c/li\u003e\n\u003cli\u003eHampton MA, Lee HJ, Locat J Submarine landslides. Reviews of geophysics, 34(1), 33-59.\u003c/li\u003e\n\u003cli\u003eHayir A, Seseogullari B, Kilinc İ, et al (2008) Scenarios of tsunami amplitudes in the north eastern coast of Sea of Marmara generated by submarine mass failure. Coast Eng 55:333\u0026ndash;356. https://doi.org/10.1016/j.coastaleng.2007.12.001\u003c/li\u003e\n\u003cli\u003eHsu S K, Tsai C H, Ku C Y, et al. Flow of turbidity currents as evidenced by failure of submarine telecommunication cables[C]//International Conference on Seafloor Map** for Geohazard Assessment, Extended Abstracts, Rendiconti online, Societ\u0026agrave; Geologica Italiana. 2009, 7: 167-171.\u003c/li\u003e\n\u003cli\u003eIlstad T, De Blasio FV, Elverhoi A, et al (2004) On the frontal dynamics and morphology of submarine debris flows. Mar Geol 213:481\u0026ndash;497. https://doi.org/10.1016/j.margeo.2004.10.020\u003c/li\u003e\n\u003cli\u003eLiu J (2015) Impact forces of submarine landslides on offshore pipelines. Ocean Engineering, 95, 116-127.\u003c/li\u003e\n\u003cli\u003eMao J, Zhao L, Di Y, et al (2020) A resolved CFD\u0026ndash;DEM approach for the simulation of landslides and impulse waves. Comput Methods Appl Mechanics and Engineering, 359, 112750.\u003c/li\u003e\n\u003cli\u003eMasson DG, Harbitz CB, Wynn RB, et al (2006) Submarine landslides: processes, triggers and hazard prediction. Philos Trans R Soc Math Phys Eng Sci 364:2009\u0026ndash;2039. https://doi.org/10.1098/rsta.2006.1810\u003c/li\u003e\n\u003cli\u003eNakata K, Katsumata A, Muhari A (2020) Submarine landslide source models consistent with multiple tsunami records of the 2018 Palu tsunami, Sulawesi, Indonesia. Earth Planets Space 72:1\u0026ndash;16. https://doi.org/10.1186/s40623-020-01169-3\u003c/li\u003e\n\u003cli\u003ePoupardin A, Calais E, Heinrich P, et al (2020) Deep submarine landslide contribution to the 2010 Haiti earthquake tsunami. Nat Hazards Earth Syst Sci 20:2055\u0026ndash;2065. https://doi.org/10.5194/nhess-20-2055-2020\u003c/li\u003e\n\u003cli\u003ePudasaini SP (2012) A general two‐phase debris flow model. J Geophys Res Earth Surf 117:2011JF002186. https://doi.org/10.1029/2011JF002186\u003c/li\u003e\n\u003cli\u003eSaito Y, Yang ZS, Hori K (2001) The Huanghe (Yellow River) and Changjiang (Yangtze River) deltas: a review on their characteristics, evolution and sediment discharge during the Holocene. GEOMORPHOLOGY 41:219\u0026ndash;231. https://doi.org/10.1016/S0169-555X(01)00118-0\u003c/li\u003e\n\u003cli\u003eSCHWARZ HU (1982) Subaqueous slope failures ― Experiments and modern occurrences. Subaqueous Slope Fail ― Exp Mod Occur 11.\u003c/li\u003e\n\u003cli\u003eSequeiros OE (2012) Estimating turbidity current conditions from channel morphology: A Froude number approach. J Geophys Res Oceans 117:2011JC007201. https://doi.org/10.1029/2011JC007201\u003c/li\u003e\n\u003cli\u003eSilver MMW (2023) Cohesion, permeability, and slope failure dynamics: Implications for failure morphology and tsunamigenesis from benchtop flume experiments. Marine Geology 462: 107079.\u003c/li\u003e\n\u003cli\u003eS\u0026oslash;rlie ER (2023) Physical model tests of clay-rich submarine landslides and resulting impact forces on offshore foundations. Ocean Engineering, 2023, 273: 113966.\u003c/li\u003e\n\u003cli\u003eTakahashi H, Fujii N, Sassa S (2020) Centrifuge model tests of earthquake-induced submarine landslide. Int J Phys Model Geotech 20:254\u0026ndash;266. https://doi.org/10.1680/jphmg.18.00048\u003c/li\u003e\n\u003cli\u003eTappin DR, Watts P, McMurtry GM, et al (2001) The Sissano, Papua New Guinea tsunami of July 1998 \u0026mdash; offshore evidence on the source mechanism. Mar Geol 175:1\u0026ndash;23. https://doi.org/10.1016/S0025-3227(01)00131-1\u003c/li\u003e\n\u003cli\u003eWang F, Dai Z, Nakahara Y, Sonoyama T (2018) Experimental study on impact behavior of submarine landslides on undersea communication cables. Ocean Eng 148:530\u0026ndash;537. https://doi.org/10.1016/j.oceaneng.2017.11.050\u003c/li\u003e\n\u003cli\u003eWu H, Xiong H, Chen X (2023) Particle shape effects on submarine landslides via CFD-DEM. Ocean Engineering，2023，284: 115140．\u003c/li\u003e\n\u003cli\u003eYang B (1987) Study of the influence of sediment loads discharged from Huanghe River on sedimentation in the Bohai and Yellow seas. Deep Sea Res Part B Oceanogr Lit Rev 34:757. https://doi.org/10.1016/0198-0254(87)90177-4\u003c/li\u003e\n\u003cli\u003eZakeri A, H\u0026oslash;eg K, Nadim F (2008) Submarine debris flow impact on pipelines \u0026mdash; Part I: Experimental investigation. Coastal engineering, 55(12), 1209-1218.\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":true,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"natural-hazards","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"nhaz","sideBox":"Learn more about [Natural Hazards](https://www.springer.com/journal/11069)","snPcode":"11069","submissionUrl":"https://submission.nature.com/new-submission/11069/3","title":"Natural Hazards","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"earthquake, submarine landslide, movement characteristic, influence factor, flume experiment","lastPublishedDoi":"10.21203/rs.3.rs-4487432/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-4487432/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eEarthquake-induced submarine landslides are destructive mass movement events impacting many marine environments. In this study, a novel vibrating flume tank was developed to study the macroscopic phenomenon of submarine landslide movement triggered by earthquakes. The results showed the movement of the sliding body has the characteristics of periodic and intermittent flow. The sliding body strikes the structure on the slope, and the force of the structure quickly reaches its peak value, then fluctuates near that value for a period of time before decreasing rapidly. A higher clay content enhanced the plastic deformation of the sliding body and the movement velocity of the sliding body was reduced. When the earthquake vibration frequency increased, the average velocity of the sliding body increased. The electrolyte in seawater enhances the water pressure and plays the role of lubricant. As the electrolyte concentration in the seawater increased, the velocity of the sliding body movement increased accordingly due to the lower friction. When the seabed slope gradient increased, the erosion effect of the sliding body on the seabed slope became stronger. As the volume of the sliding body increased, the movement velocity increased. This research can provide a basis for evaluating the hazards of submarine landslides, which is of great significance for preventing and avoiding disasters caused by submarine landslides.\u003c/p\u003e","manuscriptTitle":"Experimental study on movement characteristics and influence factors of submarine landslide triggered by earthquake","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-07-15 12:17:07","doi":"10.21203/rs.3.rs-4487432/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"reviewerAgreed","content":"","date":"2024-06-25T00:30:15+00:00","index":0,"fulltext":""},{"type":"reviewersInvited","content":"","date":"2024-06-24T02:01:49+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"Natural Hazards","date":"2024-06-22T11:19:41+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2024-06-03T02:57:12+00:00","index":"","fulltext":""},{"type":"submitted","content":"Natural Hazards","date":"2024-06-01T19:40:57+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"natural-hazards","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"nhaz","sideBox":"Learn more about [Natural Hazards](https://www.springer.com/journal/11069)","snPcode":"11069","submissionUrl":"https://submission.nature.com/new-submission/11069/3","title":"Natural Hazards","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"144aba04-b837-4410-9fac-6ae9e45db080","owner":[],"postedDate":"July 15th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2024-12-09T16:08:10+00:00","versionOfRecord":{"articleIdentity":"rs-4487432","link":"https://doi.org/10.1007/s11069-024-07048-4","journal":{"identity":"natural-hazards","isVorOnly":false,"title":"Natural Hazards"},"publishedOn":"2024-12-02 15:58:14","publishedOnDateReadable":"December 2nd, 2024"},"versionCreatedAt":"2024-07-15 12:17:07","video":"","vorDoi":"10.1007/s11069-024-07048-4","vorDoiUrl":"https://doi.org/10.1007/s11069-024-07048-4","workflowStages":[]},"version":"v1","identity":"rs-4487432","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-4487432","identity":"rs-4487432","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}