{"paper_id":"331e7984-e687-47b6-8925-4f6089d67680","body_text":"An Experimental Assessment of Piled Raft Foundation Under Axial and Eccentric Loading in the Scenario of Granular Soil Conditions | 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 An Experimental Assessment of Piled Raft Foundation Under Axial and Eccentric Loading in the Scenario of Granular Soil Conditions Mohd Aaqib, Mohd Yousuf Shah This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-5432554/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract This study evaluates the performance of different piled raft foundation systems under axial and eccentric loading in granular soils, considering both loose and dense sand conditions. The focus is on assessing their load-bearing capacities, settlement behavior, and tilt performance. Also, this study introduces a novel comparative analysis of tilt performance under eccentric loading and demonstrates the effectiveness of geogrid reinforcement in enhancing load distribution. The results indicate that axial loading outperformed eccentric loading across all systems. The Vertical Piled Raft (VPR) showed a 59.77% higher bearing capacity in dense sand under axial loading and a 50.34% improvement in loose sand. The Battered Piled Raft (BPR) system exhibited the highest load-bearing capacity i.e. 14.36% greater than VPR and 90.48% higher than the Disconnected Piled Raft (DPR). The VPR system significantly surpassed DPR, achieving 20 mm settlement at 580 kPa, a 12.91% improvement over DPR, which settled at 420 kPa. The Geogrid-Reinforced Piled Raft (GPR) system improved load distribution, showing a 54.83% increase in bearing capacity over DPR, reaching 600 kPa. Lastly, the Connected Piled Raft (CPR) proved more effective in reducing tilt than DPR, with a tilt reduction factor (TRF) of 0.25 compared to DPR’s 0.55, limiting tilt to 0.3 degrees. Piled raft foundation axial and eccentric loading granular soils load-bearing capacities settlement behavior tilt performance tilt reduction factor Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 Figure 12 Figure 13 Figure 14 Figure 15 1. Introduction Raft foundations are commonly used to support structures where strong soil layers are located at shallow depths, as noted by [ 1 ], [ 2 ], [ 3 ], [ 4 ]. However, in cases where the soil lacks sufficient strength to bear structural loads, piled raft foundations provide an efficient and economical alternative. In these systems, the raft primarily carries the load, while the piles reduce settlement, enhancing both load-bearing capacity and settlement control by distributing the load through the raft and providing additional support via the piles. Typically, the piles are connected to the raft, enabling load sharing between the two elements. Additionally, disconnected piled rafts are used to further reduce settlement, exhibiting unique behavior under different loading conditions, such as eccentric loads, as highlighted by [ 5 ], [ 6 ], [ 7 ]. Even when strong soil layers are present at shallow depths, raft foundations may still induce excessive settlement. Introducing piles beneath the raft mitigates the risk of differential settlement, a concept first proposed by [ 8 ] and later confirmed through extensive research that demonstrated the effectiveness of pile-raft systems under vertical loads. Historically, early studies such as [ 9 ] explored the number of piles required to achieve acceptable settlement levels beneath a raft. [ 10 ] the efficient design of piled rafts, while [ 11 ] used centrifuge modeling to investigate piled raft behavior, demonstrating the effectiveness of piles in mitigating differential settlements. [ 6 ] further evaluated the improved performance of rafts with the inclusion of piles. [ 12 ] analysed both horizontal and vertical loads on piled rafts, and [ 13 ] conducted a parametric study on pile positioning, number, and length. Moreover, [ 14 ], [ 15 ] examined disconnected piled rafts, where piles acted as subsoil reinforcement rather than structural elements. Piled raft foundations are also subjected to lateral forces, such as wind and seismic actions, which can cause eccentric loading and tilt, particularly in slender buildings. In such scenarios, piles beneath the raft help mitigate tilt and improve stability. The dynamic and seismic behavior of piled rafts has been extensively studied, with [ 5 ] showing through shake table tests that the inclusion of piles enhances foundation performance, particularly in earthquake-prone regions. In cohesionless soils, studies by [ 16 ], [ 17 ], [ 18 ] analysed load-sharing ratios, examining how load is distributed between piles and rafts. [ 19 ], through finite element analysis, demonstrated that concentrating piles in the central area of the raft optimizes design by minimizing the total pile length required, contributing to cost efficiency. Their study also found that non-connected piled raft systems significantly reduce settlement and internal bending moments by stiffening the underlying soil. Similarly, [ 20 ] emphasized the importance of raft-soil interaction, showing that physical model tests and numerical simulations accurately predict settlement behavior, challenging the traditional assumption that all loads are carried by piles. [ 21 ] a three-stage design approach, emphasizing that strategically placed piles can improve settlement performance and load-bearing capacity while reducing the number of piles needed. Despite these advancements, limited research exists on the behavior of piled rafts under eccentric loading, highlighting the importance of understanding the performance of both connected and disconnected piled rafts in such conditions, as emphasized by [ 22 ], [ 23 ]. This study aims to investigate the behavioral response of piled raft foundations under eccentric loading, focusing on various configurations such as unpiled rafts, disconnected piled rafts, geogrid-reinforced piled rafts, vertical piled rafts, and battered piled rafts. The research compares settlement and bearing capacity under both axial and eccentric loading conditions, contributing to a deeper understanding of how these systems perform under diverse stresses. 2. Materials and Methodology 2.1 Sand: The experiment utilized dry, clean sand, as shown in Fig. 1 , which was sourced from the Sindh River in the Ganderbal district of Jammu and Kashmir, India. The sand particles were predominantly rounded or sub-rounded. The specific gravity of the sand was measured at 2.66. The minimum dry unit weight was 15.3 kN/m³, while the maximum dry unit weight was 18.9 kN/m³. A sieve analysis was performed to obtain the particle size distribution curve, as illustrated in Fig. 2 . The coefficients of curvature (C c ) and uniformity (C u ) were determined to be 0.82 and 3.39, respectively. The sand exhibited relative densities of 35% in loose conditions and 75% in dense conditions. Based on the Indian Standard Soil Classification System, the sand is classified as poorly graded. The detailed properties of the sand are presented in Table 1 . Table 1 Properties of Sand Used in Experimentation S No. Parameters Values 1 Mean Diameter (D 50 ) – mm 0.50 2 Effective diameter (D 10 ) – mm 0.18 3 Cofficient Of Uniformity (C u ) 3.39 4 Cofficient Of Curvature (C c ) 0.82 5 Specific Gravity (G) 2.66 6 Maximum Dry Unit Weight (γ d ) max . – kN/m 3 18.9 7 Minimum Dry Unit Weight (γ d ) min . – kN/m 3 15.3 8 Angle Of Internal Friction (φ⁰) – Degrees at 35% Density 29.49 10 Angle Of Internal Friction (φ⁰) – Degrees at 75% Density 40.50 11 Soil Type (ISSCS) SP 2.2 Piled Raft: The model piled raft consists of a raft with dimensions of 20 cm x 20 cm and a thickness of 1.5 cm, supported by four mild steel piles. Each pile has a diameter of 2 cm and a length of 30 cm. The raft is secured to the piles using a nut-bolt system, designed to simulate real-world conditions. Two types of piled rafts are used in this study: a battered piled raft, with piles angled at 25° to better distribute lateral forces and improve stability, and a vertical piled raft, with straight piles to support vertical loads. This configuration ensures an accurate representation of piled-raft behavior in practical applications. The piles and rafts in the disconnected piled raft (DPR) have the same dimensions. Figure 3 illustrates the different piled rafts used in the study, where Fig. 3 (a) shows the vertical piled raft, Fig. 3 (b) shows the battered piled raft, Fig. 3 (c) displays the piles, and Fig. 3 (d) depicts the raft used in the study. The decision to use a rigid steel foundation model in this study was primarily made to ensure consistency with previous research in the field, where similar models were used for experimental studies. The use of steel allows for greater control over the physical modeling process, as steel provides a uniform and consistent material behavior, which is essential when focusing on specific variables like load distribution and interaction effects. Additionally, rigid steel models are easier to manufacture with precise dimensions and offer higher durability during repetitive testing. While it is acknowledged that practical foundation systems typically use concrete, the use of steel models serves as a simplified approximation. 2.3 Geogrid: The geogrid used for the tests was sourced from M/S Strata Systems (India) Pvt. Ltd., as shown in Fig. 4 . This biaxial geogrid provides strength in both the longitudinal and transverse directions, making it an essential component for geotechnical engineering applications requiring multidirectional reinforcement. Its high tensile strength makes it ideal for improving the load-bearing capacity of soil structures. Additionally, the geogrid's durability ensures its suitability for long-term use in various geotechnical projects. By improving stability, reducing deformation, and distributing loads more efficiently, the geogrid significantly enhances the mechanical properties of soil structures. 2.4 Experimental Setup: The experimental setup, depicted in Figs. 5 , 6 , and 7 , was meticulously designed to analyze the behavior of foundation piles under varying loads. Key components of the setup included a testing tank, magnetic stand, sand, LVDTs (Linear Variable Differential Transformers), and a proving ring. In Fig. 5 , the testing tank, measuring 1m x 1m x 1m, was filled with sand to a height of 80 cm using the raining technique, which ensured uniform compaction and minimized density variations. This method was critical for achieving consistent sand distribution, simulating realistic soil conditions for the experiment. The piles were vertically inserted into the sand with a 10 mm penetration to ensure proper seating and alignment. As the tank was gradually filled to the required level, the piles were held in place and subsequently secured to the raft using nuts and bolts to maintain stability throughout the experiment. A manual load was applied to the raft using a loading jack, progressively increasing to simulate real-life loading conditions. The load application continued until the foundation's behavior reached failure conditions and could no longer be reliably analysed. During the experiment, the settlement of the piles was measured using LVDTs, which were mounted on a magnetic stand for stability. These LVDTs were connected to a high-precision data logger, providing real-time monitoring of pile displacement for continuous and accurate measurement of settlement. The proving ring was used to precisely measure the applied loads, ensuring controlled and accurate load increments throughout the experiment. Figure 6 shows the overall experimental arrangement, including the test tank, screen, data logger, and LVDTs. The LVDTs were connected to a high-precision data acquisition system, which continuously recorded settlement data and displayed it in real-time on the screen. This setup was essential for providing instant feedback, allowing for real-time analysis and adjustments as the loads were applied. The data logger played a critical role in capturing high-resolution data from the LVDTs, offering a thorough understanding of pile behavior during the experiment. This combination of continuous observation, accurate data logging, and real-time feedback ensured that settlement measurements were highly reliable during load application. Additionally, the system allowed researchers to monitor any sudden changes in pile behavior, such as excessive settlement or failure, and make necessary adjustments to the load application process, enhancing the experiment's overall accuracy and reliability. In Fig. 7 , the installation of the piles is depicted. The image on the left shows the piles equipped with strain gauges, which were used to measure the forces acting on the piles during the experiment. These strain gauges provided essential data on the structural response of the piles under different load conditions. The right-side image illustrates the process of sand filling after the installation of the piles, ensuring that the piles were securely embedded within the sand. The sand was poured to the required height, creating a stable testing environment by fully covering the piles, thus allowing the experiment to proceed under realistic conditions. This experimental setup was meticulously designed to provide accurate, real-time data on the behavior of piles under load. The use of LVDTs, strain gauges, and a data logging system ensured precise measurement of settlement and forces. Additionally, the proving ring allowed for controlled load application. The continuous monitoring and feedback mechanisms, facilitated by the screen and data logger, made this setup ideal for studying foundation behavior under various load conditions, ensuring reliable and detailed insights into the performance of the piled raft system. 2.5 Scale Effect: The findings of this study are based on physical laboratory modeling of foundation behavior, designed to replicate the behavior of full-scale prototypes. Laboratory modeling is commonly employed because conducting full-scale loading tests can be impractical due to factors such as high costs, large space requirements, and the extended duration needed to complete these tests. Scaled models provide an efficient and feasible alternative for studying foundation behavior under different loading conditions. However, minimizing scaling effects is essential to ensure that the data obtained from small-scale models closely approximates the behavior of actual prototypes. One of the primary challenges with scaled models is the potential for scaling effects, particularly when working with granular soils. These effects can lead to discrepancies between the observed behavior in laboratory models and that of full-scale prototypes [ 24 ]. Such discrepancies often arise from differences in stress levels between the laboratory models and full-scale field prototypes. Additionally, factors like the ratio of footing width to particle size play a significant role in the results obtained from scaled models [ 25 ]. A critical parameter influencing scaling effects in granular soils is the relationship between the pile diameter (d) and the mean particle size of the soil (d 50 ). When the ratio of pile diameter to mean particle size exceeds a certain threshold, the influence of particle size on the pile’s base resistance diminishes. According to [ 26 ], when this ratio exceeds 20, the effect of particle size on pile base resistance becomes negligible. In this study, the ratio is 40, with the model pile having a diameter of 20 mm and the soil’s mean particle size being 0.5 mm. This large ratio indicates that scaling effects due to particle size are minimal, making the model suitable for studying the load-bearing behavior of piled-raft foundations. Another key consideration in the experimental design is ensuring that the bottom boundary of the testing tank does not interfere with the load transfer mechanisms or settlement behavior of the piles and raft. To achieve this, the distance from the pile tip to the bottom boundary of the tank is maintained at more than 10 times the pile diameter. This setup prevents the boundary conditions from artificially constraining soil deformation or altering the settlement response, leading to more accurate results that closely mimic real-world scenarios. 3. Results and Discussions 3.1 Behavioral Response of Piled Rafts in Dense Soil Conditions: Figures 8 and 9 show the pressure-settlement curves for axial and eccentric loading on different foundation systems in dense sand. This analysis compares the bearing capacity and settlement behavior of five foundation systems: Unpiled Rafts (UPR), Disconnected Piled Rafts (DPR), Vertical Piled Rafts (VPR), Geogrid Reinforced Piled Rafts (GPR), and Battered Piled Rafts (BPR). The key performance metrics were the bearing capacity at 20 mm settlement and the overall settlement behavior as pressure increased. The Unpiled Raft (UPR) system, lacking pile support, exhibited the highest settlement under load, making it the least effective foundation system. UPR reached 20 mm settlement at a relatively low pressure of approximately 180 kPa, and as pressure increased beyond 500 kPa, the settlement exceeded 50 mm. This significant deformation under moderate to high loads underscored the poor load-bearing capacity of UPR, as the absence of pile support prevented the foundation from adequately distributing the load, resulting in excessive settlement. In contrast, the Disconnected Piled Raft (DPR) system showed notable improvement over UPR. DPR achieved 20 mm settlement at around 420 kPa, nearly doubling the pressure resistance of UPR, with a 99.68% increase in bearing capacity. The inclusion of piles enhanced DPR’s performance, although the disconnected nature of the piles limited efficient load transfer between the raft and piles, resulting in moderate settlement compared to fully connected systems. While DPR outperformed UPR in both bearing capacity and settlement, it remained less effective than VPR, GPR, and BPR, which featured more integrated load-bearing structures. The Geogrid Reinforced Piled Raft (GPR) system demonstrated settlement behavior similar to VPR, with 20 mm settlement occurring at around 600 kPa, marking a 54.83% increase in bearing capacity. The incorporation of geogrid reinforcement in GPR provided an additional advantage in load distribution, reducing differential settlement and enhancing the foundation's ability to handle uneven loads. This reinforcement made GPR slightly more efficient than VPR, as it better controlled settlement and improved bearing capacity, particularly in cases where the foundation had to support large or unevenly distributed loads. The Vertical Piled Raft (VPR) system performed significantly better than both UPR and DPR, reaching 20 mm settlement at a pressure of approximately 580 kPa, with a 12.91% increase in bearing capacity. The vertical piles in VPR transferred the load deeper into the soil layers, reducing overall settlement. This design made VPR suitable for moderate to high-load applications in dense sand. However, while VPR effectively distributed vertical loads and reduced settlement, it lacked the lateral resistance provided by battered piles in systems like BPR. The Battered Piled Raft (BPR) system outperformed all other foundation systems in this study. BPR reached 20 mm settlement at a pressure of approximately 800 kPa, demonstrating the highest load-bearing capacity with a 14.36% increase in bearing capacity. The success of BPR lay in the use of battered (angled) piles, which provided both vertical and lateral resistance. This combination resulted in excellent load distribution, with minimal settlement even under pressures as high as 1000 kPa. The ability of BPR to resist both vertical and lateral forces made it the most robust foundation system, particularly for high-load applications requiring enhanced stability. In summary, the Battered Piled Raft (BPR) system offered the highest bearing capacity and lowest settlement, making it the ideal choice for heavy load applications where both vertical and lateral stability are crucial. The Geogrid Reinforced Piled Raft (GPR) and Vertical Piled Raft (VPR) systems followed closely behind, with GPR slightly outperforming VPR due to its enhanced load distribution from the geogrid reinforcement. Both GPR and VPR are suitable for moderate to high-load conditions. 3.2 Behavioral Response of Piled Rafts in Loose Soil Conditions Figures 10 and 11 show the pressure-settlement curves for various foundation systems under axial and eccentric loading conditions in loose sand. The foundation systems evaluated include Unpiled Rafts (UPR), Disconnected Piled Rafts (DPR), Vertical Piled Rafts (VPR), and Battered Piled Rafts (BPR), with a relative density of 35% maintained to simulate loose sand conditions. The pressure-settlement responses revealed different performance levels depending on the foundation system design and applied load. The Unpiled Raft (UPR) exhibited the highest degree of settlement, indicating its poor load-bearing capacity in loose sand. Under a pressure of 100 kPa, the UPR experienced approximately 25 mm of settlement, underscoring its inability to resist significant loads. The Disconnected Piled Raft (DPR) showed improved performance over UPR but still experienced considerable settlement. At a pressure of 150 kPa, DPR settled around 15 mm, with a percentage increase in bearing capacity of 146.15%. The limited interaction between the raft and piles in DPR led to less effective load transfer, providing only moderate improvement over UPR. While DPR offered better settlement control, it remained insufficient for high-load scenarios in loose sand. The Geogrid Reinforced Piled Raft (GPR) demonstrated further improvement, primarily due to the inclusion of geogrid reinforcement. At 150 kPa, the GPR system settled around 12 mm, showing a 3.12% increase in bearing capacity compared to DPR. The geogrid reinforcement distributed the load more effectively, making GPR a more suitable option for applications requiring enhanced settlement control in loose sand. The Vertical Piled Raft (VPR) showed even better performance than GPR. At 150 kPa, VPR experienced only around 10 mm of settlement, with a percentage increase in bearing capacity of 15.15%. The vertical piles in VPR efficiently transferred the load to deeper soil layers, minimizing settlement and making VPR a viable foundation system for moderate loads in loose sand. The best performance was observed in the Battered Piled Raft (BPR) system. Even at higher pressure levels, such as 200 kPa, the BPR experienced less than 10 mm of settlement, demonstrating excellent load-bearing capacity and effective settlement control, with a percentage increase in bearing capacity of 26.32%. The angled piles provided both vertical and lateral resistance, further improving load distribution and minimizing settlement. This made BPR the most effective foundation system for high-load conditions in loose sand, where both vertical and lateral resistance are critical. When comparing the performance of foundation systems between loose and dense sand, significant differences emerged. In dense sand, UPR performed poorly, with 20 mm settlement at approximately 180 kPa and exceeding 50 mm beyond 500 kPa. In loose sand, UPR performed even worse, with 25 mm settlement occurring at only 100 kPa. DPR showed improvement over UPR, with 20 mm settlement at 420 kPa in dense sand and 15 mm settlement at 150 kPa in loose sand, but its limited load transfer kept it from being ideal for high-load conditions. VPR demonstrated much better performance, with 20 mm settlement at around 580 kPa in dense sand and only 10 mm at 150 kPa in loose sand, indicating efficient load transfer to deeper layers. Similarly, GPR showed solid performance, achieving 20 mm settlement at 600 kPa in dense sand and 12 mm at 150 kPa in loose sand, benefiting from the geogrid’s load distribution capabilities. BPR consistently outperformed all other systems, with 20 mm settlement occurring at 800 kPa in dense sand and remaining below 10 mm at 200 kPa in loose sand. The superior load distribution and enhanced vertical and lateral resistance provided by the battered piles made BPR the most suitable foundation system for both dense and loose sand under high-load conditions. 3.3 Comparison of Piled Rafts in Axial and Eccentric Loadings: The analysis of the foundation systems revealed varying performance levels under both vertical and eccentric loading conditions. Pressure Settlement Curves Subjected to Axial and Eccentric Loadings for Different Piled Rafts under loose and dense conditions has been shown in Fig. 12 . The Unpiled Raft (UPR) system exhibited significant sensitivity to eccentric loading. Under vertical loading, UPR reached 20 mm settlement at approximately 180 kPa, with a maximum settlement exceeding 55 mm at around 500 kPa. However, under eccentric loading, its performance deteriorated, with 20 mm settlement occurring at just 140 kPa, and the maximum settlement reduced to 37 mm at 250 kPa. This indicated UPR's vulnerability to eccentric loads, making it unsuitable for high-load or eccentric conditions. The pressure-settlement curves for UPR in dense sand showed that eccentric loading caused higher settlements at lower pressures, with axial loading providing about 64.23% higher bearing capacity. In loose sand, both loading conditions led to substantial settlements, but axial loading still showed a 35.65% increase in bearing capacity. The Disconnected Piled Raft (DPR) system performed better than UPR, with 20 mm settlement occurring at 420 kPa under vertical loading and 380 kPa under eccentric loading. The maximum settlement decreased slightly from 30 mm at 600 kPa under vertical loading to 28 mm at 400 kPa under eccentric loading, indicating a moderate reduction in performance. In dense sand, DPR showed approximately 115.79% higher bearing capacity under axial loading compared to eccentric loading. A similar trend was observed in loose sand, though settlements were higher under both loading conditions. Axial loading in loose sand continued to outperform eccentric loading, resulting in a 106.25% increase in bearing capacity. The Vertical Piled Raft (VPR) system demonstrated superior resistance under both vertical and eccentric loading. Under vertical loading, 20 mm settlement occurred at 600 kPa, with a maximum settlement of 30 mm at 1000 kPa. Under eccentric loading, the bearing capacity dropped to 520 kPa at 20 mm settlement, and the maximum settlement slightly decreased to 26 mm at 500 kPa. In dense sand, VPR exhibited the highest bearing capacity, with a 59.77% higher capacity under axial loading compared to eccentric loading. In loose sand, VPR maintained strong performance under both loading conditions, showing about a 50.34% increase in bearing capacity under axial loading. In summary, the analysis highlighted VPR as the most robust and reliable system, consistently maintaining excellent performance under both vertical and eccentric loading conditions. 3.4 Bearing Capacity Piled Raft Index: The Bearing Capacity Piled Raft Index (BPI) is defined as the ratio of the bearing capacity of a connected or disconnected piled raft to that of an unpiled raft foundation [ 27 ]. BPI is a crucial parameter in evaluating the performance of piled raft foundations, as it quantifies the improvement in bearing capacity achieved by incorporating piles with a raft. This index highlights the benefits of using piles in conjunction with the raft system and serves as a measure of the effectiveness of piled raft foundations in enhancing load-bearing capacity. A higher BPI value indicates a more significant improvement in bearing capacity due to the inclusion of piles. One key factor influencing the BPI is the eccentricity ratio, which affects the behavior of piled raft foundations under varying loading conditions. The eccentricity ratio (e/B), where \"e\" represents the eccentricity of the load and \"B\" the width of the foundation, plays a critical role in determining how effectively the piled raft system performs under both axial and eccentric loads. Figure 13 illustrates the relationship between BPI and the eccentricity ratio for connected piled rafts (CPR) and disconnected piled rafts (DPR) in both loose and dense sand conditions. The results indicate that as the loading transitions from axial (e/B = 0) to eccentric (e/B = 0.15), the BPI value decreases in both CPR and DPR systems. Under axial loading conditions, piled rafts demonstrate higher effectiveness, reflected in a higher BPI, as they exhibit superior load-bearing capacity. For instance, when the load is applied axially (e/B = 0), the DPR system in loose sand achieves a BPI value of approximately 2.5, while in dense sand, the BPI is slightly below 3. This demonstrates that the presence of piles significantly enhances the foundation’s bearing capacity, particularly in denser soils where the interaction between the piles and the raft is more pronounced. In comparison, the CPR system performs even better, especially in dense sand, where the BPI for loosely packed CPR is around 3.5 and about 4 in densely packed sand. This superior performance is attributed to the continuous interaction between the piles and the raft in connected systems, leading to reduced settlement and improved load distribution, allowing the foundation to handle greater loads more effectively. When the load becomes eccentric (e/B = 0.15), the BPI values for both CPR and DPR systems decrease. This reduction occurs because eccentric loading introduces additional bending moments and shear forces, which negatively affect the foundation's stability and load-bearing capacity. For the DPR system in loose sand, the BPI decreases from 2.5 under axial loading to 1.8 under eccentric loading. Similarly, in dense sand, the BPI for DPR decreases from 3 to 2.5 under eccentric conditions. The reduction in BPI under eccentric loading is more pronounced in the DPR system due to the disconnected nature of the piles and raft, limiting the system's ability to resist bending moments effectively. In contrast, the CPR system shows a smaller reduction in BPI under eccentric loading, indicating superior performance in maintaining bearing capacity. For example, in loosely packed sand, the BPI for CPR decreases from 3.5 under axial loading to 2.5 under eccentric loading. In dense sand, the BPI decreases from 4 to 3.5 under similar conditions. This smaller reduction in BPI demonstrates the advantage of the CPR system over DPR, as the connection between the piles and the raft allows for better load transfer and greater resistance to the bending moments and shear forces induced by eccentric loads. The continuous interaction between the piles and the raft in the CPR system helps distribute the loads more evenly, reducing settlement and improving overall stability. 3.5 Tilt in Piled Raft: Tilt refers to the angle at which a piled-raft foundation leans relative to its horizontal position [ 28 ], and is a critical factor in assessing the stability of foundation systems, particularly under eccentric loading conditions. Tilt is measured by calculating the inverse tangent of the difference between readings from two Linear Variable Displacement Transducers (LVDTs), divided by the distance between them. This method allows for precise measurement of the foundation's inclination or lean. Figure 14 illustrates the tilt values for Unpiled Raft (UPR), Disconnected Piled Raft (DPR), and Connected Piled Raft (CPR) systems under various load conditions. Tilt occurs when eccentric loading causes the raft to tip or lean due to uneven load distribution, a phenomenon known as differential settlement. Differential settlement arises when the applied loads are unevenly distributed across the foundation, leading to varying settlement at different points. This uneven distribution is influenced by the interaction between the piles (if present) and the surrounding soil. As the load on the foundation increases, the tilt angle generally grows, particularly in systems with less robust support structures. In the case of UPR, which lacks piles, the tilt angle increases significantly as the load is applied. Without piles to provide additional reinforcement and distribute the load evenly, the soil absorbs the full impact, leading to pronounced differential settlement and greater tilt. For example, at a low pressure of 28 kPa, the tilt in UPR is about 0.1 degrees, but as the pressure increases to 308 kPa, the tilt grows exponentially, reaching approximately 1.2 degrees. This exponential increase in tilt with rising load indicates that UPR is highly susceptible to differential settlement and tilt, making it unstable under heavy or eccentric loads. By contrast, the DPR system shows a slower increase in tilt under similar pressure conditions. The use of piles in the DPR system helps mitigate differential settlement by distributing the load more evenly, although the piles are not connected to the raft. This detachment limits the piles' effectiveness in resisting tilt, but the system still performs significantly better than UPR. For instance, the tilt in DPR starts at around 0.05 degrees at a pressure of 28 kPa and increases to about 0.8 degrees at 308 kPa, following a linear to slightly exponential trend. While the inclusion of piles reduces the severity of tilt compared to UPR, the lack of connection between the piles and the raft limits the system's ability to fully prevent tilt, especially under higher loads. The CPR system, featuring a direct connection between the piles and the raft, performs the best in minimizing tilt. This connection ensures more consistent settlement and uniform load distribution across the foundation, resulting in significantly lower tilt angles compared to both UPR and DPR systems. The CPR system increases the foundation's load-bearing capacity, reducing differential settlement and preventing excessive tilting. The continuous interaction between the piles and the raft allows for optimal load distribution, making CPR highly effective in minimizing tilt, even under higher pressure intensities. Consequently, CPR is considered the most effective foundation type for reducing tilt and maintaining stability under both vertical and eccentric loading conditions. 3.6 Tilt Reduction Factor: The Tilt Reduction Factor (TRF) is defined as the ratio of the tilt (at failure) of a piled raft under a specific eccentric load to the tilt (at failure) of a raft without piles under the same eccentric load [ 29 ]. TRF is a crucial metric used to quantify the effectiveness of piles in reducing the tilt of a piled raft foundation system under eccentric loading conditions. Essentially, it compares the tilt behavior of a piled raft to that of a raft foundation without piles, providing insight into how much tilt reduction is achieved by incorporating piles. TRF is an important measure for engineers and designers when assessing the performance of foundation systems subjected to uneven or off-center loading, which can cause structural tilting and instability. The use of piles, particularly in piled raft systems, enhances stability and reduces tilt, ensuring safer and more reliable performance under such conditions. Lower TRF values indicate better tilt reduction performance, as they reflect less tilt in the piled raft system compared to an unpiled system. Figure 15 illustrates the TRF for both connected piled rafts (CPR) and disconnected piled rafts (DPR) under various pressure conditions. In this context, pressure intensity refers to the magnitude of the load applied to the foundation, and TRF is plotted against different pressure levels to evaluate the effectiveness of each system in reducing tilt. For the CPR system, the TRF remains relatively low and consistent across the range of pressure intensities. Specifically, the TRF for CPR ranges from approximately 0.2 to 0.3, indicating that the CPR system is highly effective in reducing tilt, even as pressure increases. This consistent performance suggests that the connection between the piles and the raft in the CPR system plays a critical role in maintaining stability and minimizing tilt, regardless of the eccentric load. In practical terms, this means that the CPR system provides a reliable solution for mitigating tilt in foundations subjected to varying pressure levels, ensuring the structure remains stable and level. In contrast, the TRF for the DPR system shows greater variability with changes in pressure intensity. At lower pressure levels, such as 28 kPa and 56 kPa, the TRF for DPR is relatively low, around 0.2, indicating effective tilt reduction at these lower loads. However, as pressure intensity increases, the TRF values for DPR rise. At higher pressure levels, such as 140 kPa to 308 kPa, the TRF for DPR reaches values as high as 0.6. This increase in TRF suggests that the DPR system becomes less effective in reducing tilt as the load on the foundation increases. The variability in TRF for DPR can be attributed to the lack of connection between the piles and the raft, leading to less predictable behavior under higher loads. Without a direct connection, the piles provide less support to the raft as pressure increases, resulting in greater tilt and reduced stability. Consequently, the DPR system is less reliable for mitigating tilt under high-pressure conditions, making it less suitable for applications where large eccentric loads are expected. Overall, the comparison of TRF between CPR and DPR highlights the superior performance of the connected piled raft system in reducing tilt under eccentric loading conditions. The CPR system, with consistently low TRF values, demonstrates high effectiveness in mitigating tilt across a wide range of pressure intensities. In contrast, while the DPR system performs well at lower pressure levels, its performance diminishes as load increases, with higher TRF values indicating reduced reliability in reducing tilt under greater loads. 4. Conclusions Experimental model testing was conducted to evaluate the performance of various piled raft systems under both axial and eccentric loading conditions. The study thoroughly examined factors such as battered rafts, geosynthetic-reinforced cushions, and varying soil densities. Based on this research, the following conclusions were drawn: Across all systems, axial loading consistently outperformed eccentric loading. The Vertical Piled Raft (VPR) exhibited a 59.77% higher bearing capacity under axial loading. In loose sand, axial loading resulted in a 50.34% improvement in bearing capacity, highlighting the more favourable conditions of axial loading for piled raft systems. The BPR system demonstrated the highest load-bearing capacity, achieving 20 mm settlement at 800 kPa under axial loading i.e. 14.36% higher than VPR and 90.48% higher than the Disconnected Piled Raft (DPR). The BPR also performed well under eccentric loading at 520 kPa, making it the most robust foundation system for both vertical and lateral loads. The Connected Piled Raft (VPR) significantly outperformed the Disconnected Piled Raft (DPR). VPR reached 20 mm settlement at 580 kPa, with a 12.91% higher bearing capacity than DPR, which settled at 420 kPa. The connection between the piles and the raft in VPR allowed for better load transfer and more efficient settlement control compared to the disconnected configuration of DPR. The GPR system provided a 54.83% increase in bearing capacity over DPR, reaching 20 mm settlement at 600 kPa. The inclusion of geogrid reinforcement improved load distribution and settlement control, making GPR more effective than DPR, particularly under uneven load conditions. The Connected Piled Raft (CPR) system significantly reduced tilt, achieving a Tilt Reduction Factor (TRF) of 0.2 to 0.3, compared to the higher TRF of 0.5 to 0.6 in the DPR system. Under a pressure of 308 kPa, the CPR system limited tilt to 0.3 degrees, while the Unpiled Raft (UPR) experienced 1.2 degrees of tilt, demonstrating CPR’s superior stability and resistance to tilting. Declarations [1] Ethics approval and consent to participate: This study was conducted following the ethical standards of NIT-Srinagar, J&K, India. All participants provided informed consent to participate in the study. [2] Consent for publication: All authors have provided their consent for the publication of this manuscript. [3] Availability of data and material: The author exclusively produced all of the data through experimental testing in the laboratory and material used was available for research work. [4] Competing interests: The author affirms the absence of any competing interests. [5] Funding: The author confirms that they did not obtain any financial resources, grants, or other forms of assistance during the writing of this paper. [6] Author's contributions: Mohd Aaqib devised and conducted tests and authored the initial draft. Prof. (Dr.) M.Y. Shah contributed to the development of the approach, as well as overseeing and revising the text. [7] Acknowledgements: The authors express their profound gratitude to the NIT-Srinagar officials for their invaluable assistance in carrying out this work at the institute. 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Int J Geotech Eng 14(2). 10.1080/19386362.2018.1427658 Mandal S, Sengupta S (2017) Experimental Investigation of Eccentrically Loaded Piled Raft Resting on Soft Cohesive Soil. Indian Geotech J 47(3). 10.1007/s40098-017-0235-9 Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted 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. 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Under Axial and Eccentric Loading in the Scenario of Granular Soil Conditions\",\"fulltext\":[{\"header\":\"1. Introduction\",\"content\":\"\\u003cp\\u003eRaft foundations are commonly used to support structures where strong soil layers are located at shallow depths, as noted by [\\u003cspan citationid=\\\"CR1\\\" class=\\\"CitationRef\\\"\\u003e1\\u003c/span\\u003e], [\\u003cspan citationid=\\\"CR2\\\" class=\\\"CitationRef\\\"\\u003e2\\u003c/span\\u003e], [\\u003cspan citationid=\\\"CR3\\\" class=\\\"CitationRef\\\"\\u003e3\\u003c/span\\u003e], [\\u003cspan citationid=\\\"CR4\\\" class=\\\"CitationRef\\\"\\u003e4\\u003c/span\\u003e]. However, in cases where the soil lacks sufficient strength to bear structural loads, piled raft foundations provide an efficient and economical alternative. In these systems, the raft primarily carries the load, while the piles reduce settlement, enhancing both load-bearing capacity and settlement control by distributing the load through the raft and providing additional support via the piles. Typically, the piles are connected to the raft, enabling load sharing between the two elements.\\u003c/p\\u003e \\u003cp\\u003eAdditionally, disconnected piled rafts are used to further reduce settlement, exhibiting unique behavior under different loading conditions, such as eccentric loads, as highlighted by [\\u003cspan citationid=\\\"CR5\\\" class=\\\"CitationRef\\\"\\u003e5\\u003c/span\\u003e], [\\u003cspan citationid=\\\"CR6\\\" class=\\\"CitationRef\\\"\\u003e6\\u003c/span\\u003e], [\\u003cspan citationid=\\\"CR7\\\" class=\\\"CitationRef\\\"\\u003e7\\u003c/span\\u003e]. Even when strong soil layers are present at shallow depths, raft foundations may still induce excessive settlement. Introducing piles beneath the raft mitigates the risk of differential settlement, a concept first proposed by [\\u003cspan citationid=\\\"CR8\\\" class=\\\"CitationRef\\\"\\u003e8\\u003c/span\\u003e] and later confirmed through extensive research that demonstrated the effectiveness of pile-raft systems under vertical loads.\\u003c/p\\u003e \\u003cp\\u003eHistorically, early studies such as [\\u003cspan citationid=\\\"CR9\\\" class=\\\"CitationRef\\\"\\u003e9\\u003c/span\\u003e] explored the number of piles required to achieve acceptable settlement levels beneath a raft. [\\u003cspan citationid=\\\"CR10\\\" class=\\\"CitationRef\\\"\\u003e10\\u003c/span\\u003e] the efficient design of piled rafts, while [\\u003cspan citationid=\\\"CR11\\\" class=\\\"CitationRef\\\"\\u003e11\\u003c/span\\u003e] used centrifuge modeling to investigate piled raft behavior, demonstrating the effectiveness of piles in mitigating differential settlements. [\\u003cspan citationid=\\\"CR6\\\" class=\\\"CitationRef\\\"\\u003e6\\u003c/span\\u003e] further evaluated the improved performance of rafts with the inclusion of piles. [\\u003cspan citationid=\\\"CR12\\\" class=\\\"CitationRef\\\"\\u003e12\\u003c/span\\u003e] analysed both horizontal and vertical loads on piled rafts, and [\\u003cspan citationid=\\\"CR13\\\" class=\\\"CitationRef\\\"\\u003e13\\u003c/span\\u003e] conducted a parametric study on pile positioning, number, and length. Moreover, [\\u003cspan citationid=\\\"CR14\\\" class=\\\"CitationRef\\\"\\u003e14\\u003c/span\\u003e], [\\u003cspan citationid=\\\"CR15\\\" class=\\\"CitationRef\\\"\\u003e15\\u003c/span\\u003e] examined disconnected piled rafts, where piles acted as subsoil reinforcement rather than structural elements. Piled raft foundations are also subjected to lateral forces, such as wind and seismic actions, which can cause eccentric loading and tilt, particularly in slender buildings. In such scenarios, piles beneath the raft help mitigate tilt and improve stability. The dynamic and seismic behavior of piled rafts has been extensively studied, with [\\u003cspan citationid=\\\"CR5\\\" class=\\\"CitationRef\\\"\\u003e5\\u003c/span\\u003e] showing through shake table tests that the inclusion of piles enhances foundation performance, particularly in earthquake-prone regions.\\u003c/p\\u003e \\u003cp\\u003eIn cohesionless soils, studies by [\\u003cspan citationid=\\\"CR16\\\" class=\\\"CitationRef\\\"\\u003e16\\u003c/span\\u003e], [\\u003cspan citationid=\\\"CR17\\\" class=\\\"CitationRef\\\"\\u003e17\\u003c/span\\u003e], [\\u003cspan citationid=\\\"CR18\\\" class=\\\"CitationRef\\\"\\u003e18\\u003c/span\\u003e] analysed load-sharing ratios, examining how load is distributed between piles and rafts. [\\u003cspan citationid=\\\"CR19\\\" class=\\\"CitationRef\\\"\\u003e19\\u003c/span\\u003e], through finite element analysis, demonstrated that concentrating piles in the central area of the raft optimizes design by minimizing the total pile length required, contributing to cost efficiency. Their study also found that non-connected piled raft systems significantly reduce settlement and internal bending moments by stiffening the underlying soil. Similarly, [\\u003cspan citationid=\\\"CR20\\\" class=\\\"CitationRef\\\"\\u003e20\\u003c/span\\u003e] emphasized the importance of raft-soil interaction, showing that physical model tests and numerical simulations accurately predict settlement behavior, challenging the traditional assumption that all loads are carried by piles. [\\u003cspan citationid=\\\"CR21\\\" class=\\\"CitationRef\\\"\\u003e21\\u003c/span\\u003e] a three-stage design approach, emphasizing that strategically placed piles can improve settlement performance and load-bearing capacity while reducing the number of piles needed.\\u003c/p\\u003e \\u003cp\\u003eDespite these advancements, limited research exists on the behavior of piled rafts under eccentric loading, highlighting the importance of understanding the performance of both connected and disconnected piled rafts in such conditions, as emphasized by [\\u003cspan citationid=\\\"CR22\\\" class=\\\"CitationRef\\\"\\u003e22\\u003c/span\\u003e], [\\u003cspan citationid=\\\"CR23\\\" class=\\\"CitationRef\\\"\\u003e23\\u003c/span\\u003e]. This study aims to investigate the behavioral response of piled raft foundations under eccentric loading, focusing on various configurations such as unpiled rafts, disconnected piled rafts, geogrid-reinforced piled rafts, vertical piled rafts, and battered piled rafts. The research compares settlement and bearing capacity under both axial and eccentric loading conditions, contributing to a deeper understanding of how these systems perform under diverse stresses.\\u003c/p\\u003e\"},{\"header\":\"2. Materials and Methodology\",\"content\":\"\\u003cdiv id=\\\"Sec3\\\" class=\\\"Section2\\\"\\u003e \\u003ch2\\u003e2.1 Sand:\\u003c/h2\\u003e \\u003cp\\u003eThe experiment utilized dry, clean sand, as shown in Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig1\\\" class=\\\"InternalRef\\\"\\u003e1\\u003c/span\\u003e, which was sourced from the Sindh River in the Ganderbal district of Jammu and Kashmir, India. The sand particles were predominantly rounded or sub-rounded. The specific gravity of the sand was measured at 2.66. The minimum dry unit weight was 15.3 kN/m\\u0026sup3;, while the maximum dry unit weight was 18.9 kN/m\\u0026sup3;. A sieve analysis was performed to obtain the particle size distribution curve, as illustrated in Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig2\\\" class=\\\"InternalRef\\\"\\u003e2\\u003c/span\\u003e. The coefficients of curvature (C\\u003csub\\u003ec\\u003c/sub\\u003e) and uniformity (C\\u003csub\\u003eu\\u003c/sub\\u003e) were determined to be 0.82 and 3.39, respectively. The sand exhibited relative densities of 35% in loose conditions and 75% in dense conditions. Based on the Indian Standard Soil Classification System, the sand is classified as poorly graded. The detailed properties of the sand are presented in Table\\u0026nbsp;\\u003cspan refid=\\\"Tab1\\\" class=\\\"InternalRef\\\"\\u003e1\\u003c/span\\u003e.\\u003c/p\\u003e \\u003cp\\u003e \\u003c/p\\u003e \\u003cp\\u003e \\u003cdiv class=\\\"gridtable\\\"\\u003e\\u003ctable float=\\\"Yes\\\" id=\\\"Tab1\\\" border=\\\"1\\\"\\u003e \\u003ccaption language=\\\"En\\\"\\u003e \\u003cdiv class=\\\"CaptionNumber\\\"\\u003eTable 1\\u003c/div\\u003e \\u003cdiv class=\\\"CaptionContent\\\"\\u003e \\u003cp\\u003eProperties of Sand Used in Experimentation\\u003c/p\\u003e \\u003c/div\\u003e \\u003c/caption\\u003e \\u003ccolgroup cols=\\\"3\\\"\\u003e \\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c1\\\" colnum=\\\"1\\\"\\u003e\\u003c/div\\u003e \\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c2\\\" colnum=\\\"2\\\"\\u003e\\u003c/div\\u003e \\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c3\\\" colnum=\\\"3\\\"\\u003e\\u003c/div\\u003e \\u003cthead\\u003e \\u003ctr\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eS No.\\u003c/p\\u003e \\u003c/th\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003eParameters\\u003c/p\\u003e \\u003c/th\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003eValues\\u003c/p\\u003e \\u003c/th\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003e1\\u003c/p\\u003e \\u003c/th\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003eMean Diameter (D\\u003csub\\u003e50\\u003c/sub\\u003e) \\u0026ndash; mm\\u003c/p\\u003e \\u003c/th\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e0.50\\u003c/p\\u003e \\u003c/th\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003e2\\u003c/p\\u003e \\u003c/th\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003eEffective diameter (D\\u003csub\\u003e10\\u003c/sub\\u003e) \\u0026ndash; mm\\u003c/p\\u003e \\u003c/th\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e0.18\\u003c/p\\u003e \\u003c/th\\u003e \\u003c/tr\\u003e \\u003c/thead\\u003e \\u003ctbody\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003e3\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003eCofficient Of Uniformity (C\\u003csub\\u003eu\\u003c/sub\\u003e)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e3.39\\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=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003eCofficient Of Curvature (C\\u003csub\\u003ec\\u003c/sub\\u003e)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e0.82\\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=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003eSpecific Gravity (G)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e2.66\\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=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003eMaximum Dry Unit Weight (γ\\u003csub\\u003ed\\u003c/sub\\u003e)\\u003csub\\u003emax\\u003c/sub\\u003e. \\u0026ndash; kN/m\\u003csup\\u003e3\\u003c/sup\\u003e\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e18.9\\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=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003eMinimum Dry Unit Weight (γ\\u003csub\\u003ed\\u003c/sub\\u003e)\\u003csub\\u003emin\\u003c/sub\\u003e. \\u0026ndash; kN/m\\u003csup\\u003e3\\u003c/sup\\u003e\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e15.3\\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=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003eAngle Of Internal Friction (φ⁰) \\u0026ndash; Degrees at 35% Density\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e29.49\\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=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003eAngle Of Internal Friction (φ⁰) \\u0026ndash; Degrees at 75% Density\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e40.50\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003e11\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003eSoil Type (ISSCS)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003eSP\\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\\u003e \\u003c/p\\u003e \\u003c/div\\u003e \\u003cdiv id=\\\"Sec4\\\" class=\\\"Section2\\\"\\u003e \\u003ch2\\u003e2.2 Piled Raft:\\u003c/h2\\u003e \\u003cp\\u003eThe model piled raft consists of a raft with dimensions of 20 cm x 20 cm and a thickness of 1.5 cm, supported by four mild steel piles. Each pile has a diameter of 2 cm and a length of 30 cm. The raft is secured to the piles using a nut-bolt system, designed to simulate real-world conditions. Two types of piled rafts are used in this study: a battered piled raft, with piles angled at 25\\u0026deg; to better distribute lateral forces and improve stability, and a vertical piled raft, with straight piles to support vertical loads. This configuration ensures an accurate representation of piled-raft behavior in practical applications. The piles and rafts in the disconnected piled raft (DPR) have the same dimensions. Figure\\u0026nbsp;\\u003cspan refid=\\\"Fig3\\\" class=\\\"InternalRef\\\"\\u003e3\\u003c/span\\u003e illustrates the different piled rafts used in the study, where Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig3\\\" class=\\\"InternalRef\\\"\\u003e3\\u003c/span\\u003e(a) shows the vertical piled raft, Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig3\\\" class=\\\"InternalRef\\\"\\u003e3\\u003c/span\\u003e(b) shows the battered piled raft, Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig3\\\" class=\\\"InternalRef\\\"\\u003e3\\u003c/span\\u003e(c) displays the piles, and Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig3\\\" class=\\\"InternalRef\\\"\\u003e3\\u003c/span\\u003e(d) depicts the raft used in the study. The decision to use a rigid steel foundation model in this study was primarily made to ensure consistency with previous research in the field, where similar models were used for experimental studies. The use of steel allows for greater control over the physical modeling process, as steel provides a uniform and consistent material behavior, which is essential when focusing on specific variables like load distribution and interaction effects. Additionally, rigid steel models are easier to manufacture with precise dimensions and offer higher durability during repetitive testing. While it is acknowledged that practical foundation systems typically use concrete, the use of steel models serves as a simplified approximation.\\u003c/p\\u003e \\u003cp\\u003e \\u003c/p\\u003e \\u003c/div\\u003e \\u003cdiv id=\\\"Sec5\\\" class=\\\"Section2\\\"\\u003e \\u003ch2\\u003e2.3 Geogrid:\\u003c/h2\\u003e \\u003cp\\u003eThe geogrid used for the tests was sourced from M/S Strata Systems (India) Pvt. Ltd., as shown in Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig4\\\" class=\\\"InternalRef\\\"\\u003e4\\u003c/span\\u003e. This biaxial geogrid provides strength in both the longitudinal and transverse directions, making it an essential component for geotechnical engineering applications requiring multidirectional reinforcement. Its high tensile strength makes it ideal for improving the load-bearing capacity of soil structures. Additionally, the geogrid's durability ensures its suitability for long-term use in various geotechnical projects. By improving stability, reducing deformation, and distributing loads more efficiently, the geogrid significantly enhances the mechanical properties of soil structures.\\u003c/p\\u003e \\u003cp\\u003e \\u003c/p\\u003e \\u003c/div\\u003e \\u003cdiv id=\\\"Sec6\\\" class=\\\"Section2\\\"\\u003e \\u003ch2\\u003e2.4 Experimental Setup:\\u003c/h2\\u003e \\u003cp\\u003eThe experimental setup, depicted in Figs.\\u0026nbsp;\\u003cspan refid=\\\"Fig5\\\" class=\\\"InternalRef\\\"\\u003e5\\u003c/span\\u003e, \\u003cspan refid=\\\"Fig6\\\" class=\\\"InternalRef\\\"\\u003e6\\u003c/span\\u003e, and \\u003cspan refid=\\\"Fig7\\\" class=\\\"InternalRef\\\"\\u003e7\\u003c/span\\u003e, was meticulously designed to analyze the behavior of foundation piles under varying loads. Key components of the setup included a testing tank, magnetic stand, sand, LVDTs (Linear Variable Differential Transformers), and a proving ring. In Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig5\\\" class=\\\"InternalRef\\\"\\u003e5\\u003c/span\\u003e, the testing tank, measuring 1m x 1m x 1m, was filled with sand to a height of 80 cm using the raining technique, which ensured uniform compaction and minimized density variations. This method was critical for achieving consistent sand distribution, simulating realistic soil conditions for the experiment.\\u003c/p\\u003e \\u003cp\\u003eThe piles were vertically inserted into the sand with a 10 mm penetration to ensure proper seating and alignment. As the tank was gradually filled to the required level, the piles were held in place and subsequently secured to the raft using nuts and bolts to maintain stability throughout the experiment. A manual load was applied to the raft using a loading jack, progressively increasing to simulate real-life loading conditions. The load application continued until the foundation's behavior reached failure conditions and could no longer be reliably analysed. During the experiment, the settlement of the piles was measured using LVDTs, which were mounted on a magnetic stand for stability. These LVDTs were connected to a high-precision data logger, providing real-time monitoring of pile displacement for continuous and accurate measurement of settlement. The proving ring was used to precisely measure the applied loads, ensuring controlled and accurate load increments throughout the experiment.\\u003c/p\\u003e \\u003cp\\u003eFigure \\u003cspan refid=\\\"Fig6\\\" class=\\\"InternalRef\\\"\\u003e6\\u003c/span\\u003e shows the overall experimental arrangement, including the test tank, screen, data logger, and LVDTs. The LVDTs were connected to a high-precision data acquisition system, which continuously recorded settlement data and displayed it in real-time on the screen. This setup was essential for providing instant feedback, allowing for real-time analysis and adjustments as the loads were applied. The data logger played a critical role in capturing high-resolution data from the LVDTs, offering a thorough understanding of pile behavior during the experiment. This combination of continuous observation, accurate data logging, and real-time feedback ensured that settlement measurements were highly reliable during load application. Additionally, the system allowed researchers to monitor any sudden changes in pile behavior, such as excessive settlement or failure, and make necessary adjustments to the load application process, enhancing the experiment's overall accuracy and reliability.\\u003c/p\\u003e \\u003cp\\u003e \\u003c/p\\u003e \\u003cp\\u003e \\u003c/p\\u003e \\u003cp\\u003eIn Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig7\\\" class=\\\"InternalRef\\\"\\u003e7\\u003c/span\\u003e, the installation of the piles is depicted. The image on the left shows the piles equipped with strain gauges, which were used to measure the forces acting on the piles during the experiment. These strain gauges provided essential data on the structural response of the piles under different load conditions. The right-side image illustrates the process of sand filling after the installation of the piles, ensuring that the piles were securely embedded within the sand. The sand was poured to the required height, creating a stable testing environment by fully covering the piles, thus allowing the experiment to proceed under realistic conditions.\\u003c/p\\u003e \\u003cp\\u003eThis experimental setup was meticulously designed to provide accurate, real-time data on the behavior of piles under load. The use of LVDTs, strain gauges, and a data logging system ensured precise measurement of settlement and forces. Additionally, the proving ring allowed for controlled load application. The continuous monitoring and feedback mechanisms, facilitated by the screen and data logger, made this setup ideal for studying foundation behavior under various load conditions, ensuring reliable and detailed insights into the performance of the piled raft system.\\u003c/p\\u003e \\u003cp\\u003e \\u003c/p\\u003e \\u003c/div\\u003e \\u003cdiv id=\\\"Sec7\\\" class=\\\"Section2\\\"\\u003e \\u003ch2\\u003e2.5 Scale Effect:\\u003c/h2\\u003e \\u003cp\\u003eThe findings of this study are based on physical laboratory modeling of foundation behavior, designed to replicate the behavior of full-scale prototypes. Laboratory modeling is commonly employed because conducting full-scale loading tests can be impractical due to factors such as high costs, large space requirements, and the extended duration needed to complete these tests. Scaled models provide an efficient and feasible alternative for studying foundation behavior under different loading conditions. However, minimizing scaling effects is essential to ensure that the data obtained from small-scale models closely approximates the behavior of actual prototypes.\\u003c/p\\u003e \\u003cp\\u003eOne of the primary challenges with scaled models is the potential for scaling effects, particularly when working with granular soils. These effects can lead to discrepancies between the observed behavior in laboratory models and that of full-scale prototypes [\\u003cspan citationid=\\\"CR24\\\" class=\\\"CitationRef\\\"\\u003e24\\u003c/span\\u003e]. Such discrepancies often arise from differences in stress levels between the laboratory models and full-scale field prototypes. Additionally, factors like the ratio of footing width to particle size play a significant role in the results obtained from scaled models [\\u003cspan citationid=\\\"CR25\\\" class=\\\"CitationRef\\\"\\u003e25\\u003c/span\\u003e].\\u003c/p\\u003e \\u003cp\\u003eA critical parameter influencing scaling effects in granular soils is the relationship between the pile diameter (d) and the mean particle size of the soil (d\\u003csub\\u003e50\\u003c/sub\\u003e). When the ratio of pile diameter to mean particle size exceeds a certain threshold, the influence of particle size on the pile\\u0026rsquo;s base resistance diminishes. According to [\\u003cspan citationid=\\\"CR26\\\" class=\\\"CitationRef\\\"\\u003e26\\u003c/span\\u003e], when this ratio exceeds 20, the effect of particle size on pile base resistance becomes negligible. In this study, the ratio is 40, with the model pile having a diameter of 20 mm and the soil\\u0026rsquo;s mean particle size being 0.5 mm. This large ratio indicates that scaling effects due to particle size are minimal, making the model suitable for studying the load-bearing behavior of piled-raft foundations.\\u003c/p\\u003e \\u003cp\\u003eAnother key consideration in the experimental design is ensuring that the bottom boundary of the testing tank does not interfere with the load transfer mechanisms or settlement behavior of the piles and raft. To achieve this, the distance from the pile tip to the bottom boundary of the tank is maintained at more than 10 times the pile diameter. This setup prevents the boundary conditions from artificially constraining soil deformation or altering the settlement response, leading to more accurate results that closely mimic real-world scenarios.\\u003c/p\\u003e \\u003c/div\\u003e\"},{\"header\":\"3. Results and Discussions\",\"content\":\"\\u003cdiv id=\\\"Sec9\\\" class=\\\"Section2\\\"\\u003e \\u003ch2\\u003e3.1 Behavioral Response of Piled Rafts in Dense Soil Conditions:\\u003c/h2\\u003e \\u003cp\\u003eFigures \\u003cspan refid=\\\"Fig8\\\" class=\\\"InternalRef\\\"\\u003e8\\u003c/span\\u003e and \\u003cspan refid=\\\"Fig9\\\" class=\\\"InternalRef\\\"\\u003e9\\u003c/span\\u003e show the pressure-settlement curves for axial and eccentric loading on different foundation systems in dense sand. This analysis compares the bearing capacity and settlement behavior of five foundation systems: Unpiled Rafts (UPR), Disconnected Piled Rafts (DPR), Vertical Piled Rafts (VPR), Geogrid Reinforced Piled Rafts (GPR), and Battered Piled Rafts (BPR). The key performance metrics were the bearing capacity at 20 mm settlement and the overall settlement behavior as pressure increased.\\u003c/p\\u003e \\u003cp\\u003eThe Unpiled Raft (UPR) system, lacking pile support, exhibited the highest settlement under load, making it the least effective foundation system. UPR reached 20 mm settlement at a relatively low pressure of approximately 180 kPa, and as pressure increased beyond 500 kPa, the settlement exceeded 50 mm. This significant deformation under moderate to high loads underscored the poor load-bearing capacity of UPR, as the absence of pile support prevented the foundation from adequately distributing the load, resulting in excessive settlement.\\u003c/p\\u003e \\u003cp\\u003eIn contrast, the Disconnected Piled Raft (DPR) system showed notable improvement over UPR. DPR achieved 20 mm settlement at around 420 kPa, nearly doubling the pressure resistance of UPR, with a 99.68% increase in bearing capacity. The inclusion of piles enhanced DPR\\u0026rsquo;s performance, although the disconnected nature of the piles limited efficient load transfer between the raft and piles, resulting in moderate settlement compared to fully connected systems. While DPR outperformed UPR in both bearing capacity and settlement, it remained less effective than VPR, GPR, and BPR, which featured more integrated load-bearing structures.\\u003c/p\\u003e \\u003cp\\u003eThe Geogrid Reinforced Piled Raft (GPR) system demonstrated settlement behavior similar to VPR, with 20 mm settlement occurring at around 600 kPa, marking a 54.83% increase in bearing capacity. The incorporation of geogrid reinforcement in GPR provided an additional advantage in load distribution, reducing differential settlement and enhancing the foundation's ability to handle uneven loads. This reinforcement made GPR slightly more efficient than VPR, as it better controlled settlement and improved bearing capacity, particularly in cases where the foundation had to support large or unevenly distributed loads.\\u003c/p\\u003e \\u003cp\\u003eThe Vertical Piled Raft (VPR) system performed significantly better than both UPR and DPR, reaching 20 mm settlement at a pressure of approximately 580 kPa, with a 12.91% increase in bearing capacity. The vertical piles in VPR transferred the load deeper into the soil layers, reducing overall settlement. This design made VPR suitable for moderate to high-load applications in dense sand. However, while VPR effectively distributed vertical loads and reduced settlement, it lacked the lateral resistance provided by battered piles in systems like BPR.\\u003c/p\\u003e \\u003cp\\u003eThe Battered Piled Raft (BPR) system outperformed all other foundation systems in this study. BPR reached 20 mm settlement at a pressure of approximately 800 kPa, demonstrating the highest load-bearing capacity with a 14.36% increase in bearing capacity. The success of BPR lay in the use of battered (angled) piles, which provided both vertical and lateral resistance. This combination resulted in excellent load distribution, with minimal settlement even under pressures as high as 1000 kPa. The ability of BPR to resist both vertical and lateral forces made it the most robust foundation system, particularly for high-load applications requiring enhanced stability.\\u003c/p\\u003e \\u003cp\\u003eIn summary, the Battered Piled Raft (BPR) system offered the highest bearing capacity and lowest settlement, making it the ideal choice for heavy load applications where both vertical and lateral stability are crucial. The Geogrid Reinforced Piled Raft (GPR) and Vertical Piled Raft (VPR) systems followed closely behind, with GPR slightly outperforming VPR due to its enhanced load distribution from the geogrid reinforcement. Both GPR and VPR are suitable for moderate to high-load conditions.\\u003c/p\\u003e \\u003cp\\u003e \\u003c/p\\u003e \\u003cp\\u003e \\u003c/p\\u003e \\u003c/div\\u003e \\u003cdiv id=\\\"Sec10\\\" class=\\\"Section2\\\"\\u003e \\u003ch2\\u003e3.2 Behavioral Response of Piled Rafts in Loose Soil Conditions\\u003c/h2\\u003e \\u003cp\\u003eFigures \\u003cspan refid=\\\"Fig10\\\" class=\\\"InternalRef\\\"\\u003e10\\u003c/span\\u003e and \\u003cspan refid=\\\"Fig11\\\" class=\\\"InternalRef\\\"\\u003e11\\u003c/span\\u003e show the pressure-settlement curves for various foundation systems under axial and eccentric loading conditions in loose sand. The foundation systems evaluated include Unpiled Rafts (UPR), Disconnected Piled Rafts (DPR), Vertical Piled Rafts (VPR), and Battered Piled Rafts (BPR), with a relative density of 35% maintained to simulate loose sand conditions. The pressure-settlement responses revealed different performance levels depending on the foundation system design and applied load. The Unpiled Raft (UPR) exhibited the highest degree of settlement, indicating its poor load-bearing capacity in loose sand. Under a pressure of 100 kPa, the UPR experienced approximately 25 mm of settlement, underscoring its inability to resist significant loads. The Disconnected Piled Raft (DPR) showed improved performance over UPR but still experienced considerable settlement. At a pressure of 150 kPa, DPR settled around 15 mm, with a percentage increase in bearing capacity of 146.15%. The limited interaction between the raft and piles in DPR led to less effective load transfer, providing only moderate improvement over UPR. While DPR offered better settlement control, it remained insufficient for high-load scenarios in loose sand.\\u003c/p\\u003e \\u003cp\\u003eThe Geogrid Reinforced Piled Raft (GPR) demonstrated further improvement, primarily due to the inclusion of geogrid reinforcement. At 150 kPa, the GPR system settled around 12 mm, showing a 3.12% increase in bearing capacity compared to DPR. The geogrid reinforcement distributed the load more effectively, making GPR a more suitable option for applications requiring enhanced settlement control in loose sand. The Vertical Piled Raft (VPR) showed even better performance than GPR. At 150 kPa, VPR experienced only around 10 mm of settlement, with a percentage increase in bearing capacity of 15.15%. The vertical piles in VPR efficiently transferred the load to deeper soil layers, minimizing settlement and making VPR a viable foundation system for moderate loads in loose sand.\\u003c/p\\u003e \\u003cp\\u003eThe best performance was observed in the Battered Piled Raft (BPR) system. Even at higher pressure levels, such as 200 kPa, the BPR experienced less than 10 mm of settlement, demonstrating excellent load-bearing capacity and effective settlement control, with a percentage increase in bearing capacity of 26.32%. The angled piles provided both vertical and lateral resistance, further improving load distribution and minimizing settlement. This made BPR the most effective foundation system for high-load conditions in loose sand, where both vertical and lateral resistance are critical.\\u003c/p\\u003e \\u003cp\\u003eWhen comparing the performance of foundation systems between loose and dense sand, significant differences emerged. In dense sand, UPR performed poorly, with 20 mm settlement at approximately 180 kPa and exceeding 50 mm beyond 500 kPa. In loose sand, UPR performed even worse, with 25 mm settlement occurring at only 100 kPa. DPR showed improvement over UPR, with 20 mm settlement at 420 kPa in dense sand and 15 mm settlement at 150 kPa in loose sand, but its limited load transfer kept it from being ideal for high-load conditions. VPR demonstrated much better performance, with 20 mm settlement at around 580 kPa in dense sand and only 10 mm at 150 kPa in loose sand, indicating efficient load transfer to deeper layers. Similarly, GPR showed solid performance, achieving 20 mm settlement at 600 kPa in dense sand and 12 mm at 150 kPa in loose sand, benefiting from the geogrid\\u0026rsquo;s load distribution capabilities. BPR consistently outperformed all other systems, with 20 mm settlement occurring at 800 kPa in dense sand and remaining below 10 mm at 200 kPa in loose sand. The superior load distribution and enhanced vertical and lateral resistance provided by the battered piles made BPR the most suitable foundation system for both dense and loose sand under high-load conditions.\\u003c/p\\u003e \\u003cp\\u003e \\u003c/p\\u003e \\u003cp\\u003e \\u003c/p\\u003e \\u003c/div\\u003e \\u003cdiv id=\\\"Sec11\\\" class=\\\"Section2\\\"\\u003e \\u003ch2\\u003e3.3 Comparison of Piled Rafts in Axial and Eccentric Loadings:\\u003c/h2\\u003e \\u003cp\\u003eThe analysis of the foundation systems revealed varying performance levels under both vertical and eccentric loading conditions. Pressure Settlement Curves Subjected to Axial and Eccentric Loadings for Different Piled Rafts under loose and dense conditions has been shown in Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig12\\\" class=\\\"InternalRef\\\"\\u003e12\\u003c/span\\u003e. The Unpiled Raft (UPR) system exhibited significant sensitivity to eccentric loading. Under vertical loading, UPR reached 20 mm settlement at approximately 180 kPa, with a maximum settlement exceeding 55 mm at around 500 kPa. However, under eccentric loading, its performance deteriorated, with 20 mm settlement occurring at just 140 kPa, and the maximum settlement reduced to 37 mm at 250 kPa. This indicated UPR's vulnerability to eccentric loads, making it unsuitable for high-load or eccentric conditions. The pressure-settlement curves for UPR in dense sand showed that eccentric loading caused higher settlements at lower pressures, with axial loading providing about 64.23% higher bearing capacity. In loose sand, both loading conditions led to substantial settlements, but axial loading still showed a 35.65% increase in bearing capacity.\\u003c/p\\u003e \\u003cp\\u003eThe Disconnected Piled Raft (DPR) system performed better than UPR, with 20 mm settlement occurring at 420 kPa under vertical loading and 380 kPa under eccentric loading. The maximum settlement decreased slightly from 30 mm at 600 kPa under vertical loading to 28 mm at 400 kPa under eccentric loading, indicating a moderate reduction in performance. In dense sand, DPR showed approximately 115.79% higher bearing capacity under axial loading compared to eccentric loading. A similar trend was observed in loose sand, though settlements were higher under both loading conditions. Axial loading in loose sand continued to outperform eccentric loading, resulting in a 106.25% increase in bearing capacity.\\u003c/p\\u003e \\u003cp\\u003eThe Vertical Piled Raft (VPR) system demonstrated superior resistance under both vertical and eccentric loading. Under vertical loading, 20 mm settlement occurred at 600 kPa, with a maximum settlement of 30 mm at 1000 kPa. Under eccentric loading, the bearing capacity dropped to 520 kPa at 20 mm settlement, and the maximum settlement slightly decreased to 26 mm at 500 kPa. In dense sand, VPR exhibited the highest bearing capacity, with a 59.77% higher capacity under axial loading compared to eccentric loading. In loose sand, VPR maintained strong performance under both loading conditions, showing about a 50.34% increase in bearing capacity under axial loading. In summary, the analysis highlighted VPR as the most robust and reliable system, consistently maintaining excellent performance under both vertical and eccentric loading conditions.\\u003c/p\\u003e \\u003cp\\u003e \\u003c/p\\u003e \\u003c/div\\u003e \\u003cdiv id=\\\"Sec12\\\" class=\\\"Section2\\\"\\u003e \\u003ch2\\u003e3.4 Bearing Capacity Piled Raft Index:\\u003c/h2\\u003e \\u003cp\\u003eThe Bearing Capacity Piled Raft Index (BPI) is defined as the ratio of the bearing capacity of a connected or disconnected piled raft to that of an unpiled raft foundation [\\u003cspan citationid=\\\"CR27\\\" class=\\\"CitationRef\\\"\\u003e27\\u003c/span\\u003e]. BPI is a crucial parameter in evaluating the performance of piled raft foundations, as it quantifies the improvement in bearing capacity achieved by incorporating piles with a raft. This index highlights the benefits of using piles in conjunction with the raft system and serves as a measure of the effectiveness of piled raft foundations in enhancing load-bearing capacity. A higher BPI value indicates a more significant improvement in bearing capacity due to the inclusion of piles.\\u003c/p\\u003e \\u003cp\\u003eOne key factor influencing the BPI is the eccentricity ratio, which affects the behavior of piled raft foundations under varying loading conditions. The eccentricity ratio (e/B), where \\\"e\\\" represents the eccentricity of the load and \\\"B\\\" the width of the foundation, plays a critical role in determining how effectively the piled raft system performs under both axial and eccentric loads. Figure\\u0026nbsp;\\u003cspan refid=\\\"Fig13\\\" class=\\\"InternalRef\\\"\\u003e13\\u003c/span\\u003e illustrates the relationship between BPI and the eccentricity ratio for connected piled rafts (CPR) and disconnected piled rafts (DPR) in both loose and dense sand conditions. The results indicate that as the loading transitions from axial (e/B\\u0026thinsp;=\\u0026thinsp;0) to eccentric (e/B\\u0026thinsp;=\\u0026thinsp;0.15), the BPI value decreases in both CPR and DPR systems.\\u003c/p\\u003e \\u003cp\\u003eUnder axial loading conditions, piled rafts demonstrate higher effectiveness, reflected in a higher BPI, as they exhibit superior load-bearing capacity. For instance, when the load is applied axially (e/B\\u0026thinsp;=\\u0026thinsp;0), the DPR system in loose sand achieves a BPI value of approximately 2.5, while in dense sand, the BPI is slightly below 3. This demonstrates that the presence of piles significantly enhances the foundation\\u0026rsquo;s bearing capacity, particularly in denser soils where the interaction between the piles and the raft is more pronounced. In comparison, the CPR system performs even better, especially in dense sand, where the BPI for loosely packed CPR is around 3.5 and about 4 in densely packed sand. This superior performance is attributed to the continuous interaction between the piles and the raft in connected systems, leading to reduced settlement and improved load distribution, allowing the foundation to handle greater loads more effectively.\\u003c/p\\u003e \\u003cp\\u003eWhen the load becomes eccentric (e/B\\u0026thinsp;=\\u0026thinsp;0.15), the BPI values for both CPR and DPR systems decrease. This reduction occurs because eccentric loading introduces additional bending moments and shear forces, which negatively affect the foundation's stability and load-bearing capacity. For the DPR system in loose sand, the BPI decreases from 2.5 under axial loading to 1.8 under eccentric loading. Similarly, in dense sand, the BPI for DPR decreases from 3 to 2.5 under eccentric conditions. The reduction in BPI under eccentric loading is more pronounced in the DPR system due to the disconnected nature of the piles and raft, limiting the system's ability to resist bending moments effectively.\\u003c/p\\u003e \\u003cp\\u003eIn contrast, the CPR system shows a smaller reduction in BPI under eccentric loading, indicating superior performance in maintaining bearing capacity. For example, in loosely packed sand, the BPI for CPR decreases from 3.5 under axial loading to 2.5 under eccentric loading. In dense sand, the BPI decreases from 4 to 3.5 under similar conditions. This smaller reduction in BPI demonstrates the advantage of the CPR system over DPR, as the connection between the piles and the raft allows for better load transfer and greater resistance to the bending moments and shear forces induced by eccentric loads. The continuous interaction between the piles and the raft in the CPR system helps distribute the loads more evenly, reducing settlement and improving overall stability.\\u003c/p\\u003e \\u003cp\\u003e \\u003c/p\\u003e \\u003c/div\\u003e \\u003cdiv id=\\\"Sec13\\\" class=\\\"Section2\\\"\\u003e \\u003ch2\\u003e3.5 Tilt in Piled Raft:\\u003c/h2\\u003e \\u003cp\\u003eTilt refers to the angle at which a piled-raft foundation leans relative to its horizontal position [\\u003cspan citationid=\\\"CR28\\\" class=\\\"CitationRef\\\"\\u003e28\\u003c/span\\u003e], and is a critical factor in assessing the stability of foundation systems, particularly under eccentric loading conditions. Tilt is measured by calculating the inverse tangent of the difference between readings from two Linear Variable Displacement Transducers (LVDTs), divided by the distance between them. This method allows for precise measurement of the foundation's inclination or lean. Figure\\u0026nbsp;\\u003cspan refid=\\\"Fig14\\\" class=\\\"InternalRef\\\"\\u003e14\\u003c/span\\u003e illustrates the tilt values for Unpiled Raft (UPR), Disconnected Piled Raft (DPR), and Connected Piled Raft (CPR) systems under various load conditions.\\u003c/p\\u003e \\u003cp\\u003eTilt occurs when eccentric loading causes the raft to tip or lean due to uneven load distribution, a phenomenon known as differential settlement. Differential settlement arises when the applied loads are unevenly distributed across the foundation, leading to varying settlement at different points. This uneven distribution is influenced by the interaction between the piles (if present) and the surrounding soil. As the load on the foundation increases, the tilt angle generally grows, particularly in systems with less robust support structures.\\u003c/p\\u003e \\u003cp\\u003eIn the case of UPR, which lacks piles, the tilt angle increases significantly as the load is applied. Without piles to provide additional reinforcement and distribute the load evenly, the soil absorbs the full impact, leading to pronounced differential settlement and greater tilt. For example, at a low pressure of 28 kPa, the tilt in UPR is about 0.1 degrees, but as the pressure increases to 308 kPa, the tilt grows exponentially, reaching approximately 1.2 degrees. This exponential increase in tilt with rising load indicates that UPR is highly susceptible to differential settlement and tilt, making it unstable under heavy or eccentric loads.\\u003c/p\\u003e \\u003cp\\u003eBy contrast, the DPR system shows a slower increase in tilt under similar pressure conditions. The use of piles in the DPR system helps mitigate differential settlement by distributing the load more evenly, although the piles are not connected to the raft. This detachment limits the piles' effectiveness in resisting tilt, but the system still performs significantly better than UPR. For instance, the tilt in DPR starts at around 0.05 degrees at a pressure of 28 kPa and increases to about 0.8 degrees at 308 kPa, following a linear to slightly exponential trend. While the inclusion of piles reduces the severity of tilt compared to UPR, the lack of connection between the piles and the raft limits the system's ability to fully prevent tilt, especially under higher loads.\\u003c/p\\u003e \\u003cp\\u003eThe CPR system, featuring a direct connection between the piles and the raft, performs the best in minimizing tilt. This connection ensures more consistent settlement and uniform load distribution across the foundation, resulting in significantly lower tilt angles compared to both UPR and DPR systems. The CPR system increases the foundation's load-bearing capacity, reducing differential settlement and preventing excessive tilting. The continuous interaction between the piles and the raft allows for optimal load distribution, making CPR highly effective in minimizing tilt, even under higher pressure intensities. Consequently, CPR is considered the most effective foundation type for reducing tilt and maintaining stability under both vertical and eccentric loading conditions.\\u003c/p\\u003e \\u003cp\\u003e \\u003c/p\\u003e \\u003c/div\\u003e \\u003cdiv id=\\\"Sec14\\\" class=\\\"Section2\\\"\\u003e \\u003ch2\\u003e3.6 Tilt Reduction Factor:\\u003c/h2\\u003e \\u003cp\\u003eThe Tilt Reduction Factor (TRF) is defined as the ratio of the tilt (at failure) of a piled raft under a specific eccentric load to the tilt (at failure) of a raft without piles under the same eccentric load [\\u003cspan citationid=\\\"CR29\\\" class=\\\"CitationRef\\\"\\u003e29\\u003c/span\\u003e]. TRF is a crucial metric used to quantify the effectiveness of piles in reducing the tilt of a piled raft foundation system under eccentric loading conditions. Essentially, it compares the tilt behavior of a piled raft to that of a raft foundation without piles, providing insight into how much tilt reduction is achieved by incorporating piles. TRF is an important measure for engineers and designers when assessing the performance of foundation systems subjected to uneven or off-center loading, which can cause structural tilting and instability. The use of piles, particularly in piled raft systems, enhances stability and reduces tilt, ensuring safer and more reliable performance under such conditions. Lower TRF values indicate better tilt reduction performance, as they reflect less tilt in the piled raft system compared to an unpiled system.\\u003c/p\\u003e \\u003cp\\u003eFigure \\u003cspan refid=\\\"Fig15\\\" class=\\\"InternalRef\\\"\\u003e15\\u003c/span\\u003e illustrates the TRF for both connected piled rafts (CPR) and disconnected piled rafts (DPR) under various pressure conditions. In this context, pressure intensity refers to the magnitude of the load applied to the foundation, and TRF is plotted against different pressure levels to evaluate the effectiveness of each system in reducing tilt. For the CPR system, the TRF remains relatively low and consistent across the range of pressure intensities. Specifically, the TRF for CPR ranges from approximately 0.2 to 0.3, indicating that the CPR system is highly effective in reducing tilt, even as pressure increases. This consistent performance suggests that the connection between the piles and the raft in the CPR system plays a critical role in maintaining stability and minimizing tilt, regardless of the eccentric load. In practical terms, this means that the CPR system provides a reliable solution for mitigating tilt in foundations subjected to varying pressure levels, ensuring the structure remains stable and level.\\u003c/p\\u003e \\u003cp\\u003eIn contrast, the TRF for the DPR system shows greater variability with changes in pressure intensity. At lower pressure levels, such as 28 kPa and 56 kPa, the TRF for DPR is relatively low, around 0.2, indicating effective tilt reduction at these lower loads. However, as pressure intensity increases, the TRF values for DPR rise. At higher pressure levels, such as 140 kPa to 308 kPa, the TRF for DPR reaches values as high as 0.6. This increase in TRF suggests that the DPR system becomes less effective in reducing tilt as the load on the foundation increases.\\u003c/p\\u003e \\u003cp\\u003eThe variability in TRF for DPR can be attributed to the lack of connection between the piles and the raft, leading to less predictable behavior under higher loads. Without a direct connection, the piles provide less support to the raft as pressure increases, resulting in greater tilt and reduced stability. Consequently, the DPR system is less reliable for mitigating tilt under high-pressure conditions, making it less suitable for applications where large eccentric loads are expected.\\u003c/p\\u003e \\u003cp\\u003eOverall, the comparison of TRF between CPR and DPR highlights the superior performance of the connected piled raft system in reducing tilt under eccentric loading conditions. The CPR system, with consistently low TRF values, demonstrates high effectiveness in mitigating tilt across a wide range of pressure intensities. In contrast, while the DPR system performs well at lower pressure levels, its performance diminishes as load increases, with higher TRF values indicating reduced reliability in reducing tilt under greater loads.\\u003c/p\\u003e \\u003cp\\u003e \\u003c/p\\u003e \\u003c/div\\u003e\"},{\"header\":\"4. Conclusions\",\"content\":\"\\u003cp\\u003eExperimental model testing was conducted to evaluate the performance of various piled raft systems under both axial and eccentric loading conditions. The study thoroughly examined factors such as battered rafts, geosynthetic-reinforced cushions, and varying soil densities. Based on this research, the following conclusions were drawn:\\u003c/p\\u003e \\u003cp\\u003e \\u003col\\u003e \\u003cspan\\u003e \\u003cli\\u003e \\u003cp\\u003eAcross all systems, axial loading consistently outperformed eccentric loading. The Vertical Piled Raft (VPR) exhibited a 59.77% higher bearing capacity under axial loading. In loose sand, axial loading resulted in a 50.34% improvement in bearing capacity, highlighting the more favourable conditions of axial loading for piled raft systems.\\u003c/p\\u003e \\u003c/li\\u003e \\u003c/span\\u003e \\u003cspan\\u003e \\u003cli\\u003e \\u003cp\\u003eThe BPR system demonstrated the highest load-bearing capacity, achieving 20 mm settlement at 800 kPa under axial loading i.e. 14.36% higher than VPR and 90.48% higher than the Disconnected Piled Raft (DPR). The BPR also performed well under eccentric loading at 520 kPa, making it the most robust foundation system for both vertical and lateral loads.\\u003c/p\\u003e \\u003c/li\\u003e \\u003c/span\\u003e \\u003cspan\\u003e \\u003cli\\u003e \\u003cp\\u003eThe Connected Piled Raft (VPR) significantly outperformed the Disconnected Piled Raft (DPR). VPR reached 20 mm settlement at 580 kPa, with a 12.91% higher bearing capacity than DPR, which settled at 420 kPa. The connection between the piles and the raft in VPR allowed for better load transfer and more efficient settlement control compared to the disconnected configuration of DPR.\\u003c/p\\u003e \\u003c/li\\u003e \\u003c/span\\u003e \\u003cspan\\u003e \\u003cli\\u003e \\u003cp\\u003eThe GPR system provided a 54.83% increase in bearing capacity over DPR, reaching 20 mm settlement at 600 kPa. The inclusion of geogrid reinforcement improved load distribution and settlement control, making GPR more effective than DPR, particularly under uneven load conditions.\\u003c/p\\u003e \\u003c/li\\u003e \\u003c/span\\u003e \\u003cspan\\u003e \\u003cli\\u003e \\u003cp\\u003eThe Connected Piled Raft (CPR) system significantly reduced tilt, achieving a Tilt Reduction Factor (TRF) of 0.2 to 0.3, compared to the higher TRF of 0.5 to 0.6 in the DPR system. Under a pressure of 308 kPa, the CPR system limited tilt to 0.3 degrees, while the Unpiled Raft (UPR) experienced 1.2 degrees of tilt, demonstrating CPR\\u0026rsquo;s superior stability and resistance to tilting.\\u003c/p\\u003e \\u003c/li\\u003e \\u003c/span\\u003e \\u003c/ol\\u003e \\u003c/p\\u003e\"},{\"header\":\"Declarations\",\"content\":\"\\u003cp\\u003e\\u003cstrong\\u003e[1] Ethics approval and consent to participate:\\u003c/strong\\u003e\\u003cstrong\\u003e\\u0026nbsp;\\u003c/strong\\u003eThis study was conducted following the ethical standards of NIT-Srinagar, J\\u0026amp;K, India. All participants provided informed consent to participate in the study.\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003e[2] Consent for publication:\\u003c/strong\\u003e\\u003cstrong\\u003e\\u0026nbsp;\\u003c/strong\\u003eAll authors have provided their consent for the publication of this manuscript.\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003e[3] Availability of data and material:\\u003c/strong\\u003e\\u003cstrong\\u003e\\u0026nbsp;\\u003c/strong\\u003eThe author exclusively produced all of the data through experimental testing in the laboratory and material used was available for research work.\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003e[4] Competing interests:\\u0026nbsp;\\u003c/strong\\u003eThe author affirms the absence of any competing interests.\\u003cstrong\\u003e\\u0026nbsp;\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003e[5] Funding:\\u003c/strong\\u003e\\u003cstrong\\u003e\\u0026nbsp;\\u003c/strong\\u003eThe author confirms that they did not obtain any financial resources, grants, or other forms of assistance during the writing of this paper.\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003e[6] Author\\u0026apos;s contributions:\\u003c/strong\\u003e\\u003cstrong\\u003e\\u0026nbsp;\\u003c/strong\\u003eMohd Aaqib devised and conducted tests and authored the initial draft. Prof. (Dr.) M.Y. Shah contributed to the development of the approach, as well as overseeing and revising the text.\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003e[7] Acknowledgements:\\u003c/strong\\u003e\\u003cstrong\\u003e\\u0026nbsp;\\u003c/strong\\u003eThe authors express their profound gratitude to the NIT-Srinagar officials for their invaluable assistance in carrying out this work at the institute.\\u003c/p\\u003e\"},{\"header\":\"References\",\"content\":\"\\u003col\\u003e\\u003cli\\u003e\\u003cspan\\u003ePoulos HG (2001) Piled raft foundations: Design and applications, \\u003cem\\u003eGeotechnique\\u003c/em\\u003e, vol. 51, no. 2, \\u003cspan class=\\\"ExternalRef\\\"\\u003e\\u003cspan class=\\\"RefSource\\\"\\u003e10.1680/geot.51.2.95.40292\\u003c/span\\u003e\\u003cspan address=\\\"10.1680/geot.51.2.95.40292\\\" targettype=\\\"DOI\\\" class=\\\"RefTarget\\\"\\u003e\\u003c/span\\u003e\\u003c/span\\u003e\\u003c/span\\u003e\\u003c/li\\u003e \\u003cli\\u003e\\u003cspan\\u003eMagar J, Kudtarkar A, Pachpohe J, Nagargoje P (2020) Study and Analysis of Types of Foundation and Design Construction. Int Res J Eng Technol 7(8). \\u003cspan class=\\\"ExternalRef\\\"\\u003e\\u003cspan class=\\\"RefSource\\\"\\u003e10.5281/zenodo.3995061\\u003c/span\\u003e\\u003cspan address=\\\"10.5281/zenodo.3995061\\\" targettype=\\\"DOI\\\" class=\\\"RefTarget\\\"\\u003e\\u003c/span\\u003e\\u003c/span\\u003e\\u003c/span\\u003e\\u003c/li\\u003e \\u003cli\\u003e\\u003cspan\\u003ePoulos HG (2005) Piled Raft and Compensated Piled Raft Foundations for Soft Soil Sites. \\u003cspan class=\\\"ExternalRef\\\"\\u003e\\u003cspan class=\\\"RefSource\\\"\\u003e10.1061/40772(170)2\\u003c/span\\u003e\\u003cspan address=\\\"10.1061/40772(170)2\\\" targettype=\\\"DOI\\\" class=\\\"RefTarget\\\"\\u003e\\u003c/span\\u003e\\u003c/span\\u003e\\u003c/span\\u003e\\u003c/li\\u003e \\u003cli\\u003e\\u003cspan\\u003eKumar V, Kumar A (2018) An experimental study to analyse the behaviour of piled-raft foundation model under the application of vertical load. 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Indian Geotech J 47(3). \\u003cspan class=\\\"ExternalRef\\\"\\u003e\\u003cspan class=\\\"RefSource\\\"\\u003e10.1007/s40098-017-0235-9\\u003c/span\\u003e\\u003cspan address=\\\"10.1007/s40098-017-0235-9\\\" targettype=\\\"DOI\\\" class=\\\"RefTarget\\\"\\u003e\\u003c/span\\u003e\\u003c/span\\u003e\\u003c/span\\u003e\\u003c/li\\u003e\\u003c/ol\\u003e\"}],\"fulltextSource\":\"\",\"fullText\":\"\",\"funders\":[],\"hasAdminPriorityOnWorkflow\":false,\"hasManuscriptDocX\":true,\"hasOptedInToPreprint\":true,\"hasPassedJournalQc\":\"\",\"hasAnyPriority\":false,\"hideJournal\":true,\"highlight\":\"\",\"institution\":\"\",\"isAcceptedByJournal\":false,\"isAuthorSuppliedPdf\":false,\"isDeskRejected\":\"\",\"isHiddenFromSearch\":false,\"isInQc\":false,\"isInWorkflow\":false,\"isPdf\":false,\"isPdfUpToDate\":true,\"isWithdrawnOrRetracted\":false,\"journal\":{\"display\":true,\"email\":\"info@researchsquare.com\",\"identity\":\"researchsquare\",\"isNatureJournal\":false,\"hasQc\":true,\"allowDirectSubmit\":true,\"externalIdentity\":\"\",\"sideBox\":\"\",\"snPcode\":\"\",\"submissionUrl\":\"/submission\",\"title\":\"Research Square\",\"twitterHandle\":\"researchsquare\",\"acdcEnabled\":true,\"dfaEnabled\":false,\"editorialSystem\":\"\",\"reportingPortfolio\":\"\",\"inReviewEnabled\":false,\"inReviewRevisionsEnabled\":true},\"keywords\":\"Piled raft foundation, axial and eccentric loading, granular soils, load-bearing capacities, settlement behavior, tilt performance, tilt reduction factor\",\"lastPublishedDoi\":\"10.21203/rs.3.rs-5432554/v1\",\"lastPublishedDoiUrl\":\"https://doi.org/10.21203/rs.3.rs-5432554/v1\",\"license\":{\"name\":\"CC BY 4.0\",\"url\":\"https://creativecommons.org/licenses/by/4.0/\"},\"manuscriptAbstract\":\"\\u003cp\\u003eThis study evaluates the performance of different piled raft foundation systems under axial and eccentric loading in granular soils, considering both loose and dense sand conditions. The focus is on assessing their load-bearing capacities, settlement behavior, and tilt performance. Also, this study introduces a novel comparative analysis of tilt performance under eccentric loading and demonstrates the effectiveness of geogrid reinforcement in enhancing load distribution. The results indicate that axial loading outperformed eccentric loading across all systems. The Vertical Piled Raft (VPR) showed a 59.77% higher bearing capacity in dense sand under axial loading and a 50.34% improvement in loose sand. The Battered Piled Raft (BPR) system exhibited the highest load-bearing capacity i.e. 14.36% greater than VPR and 90.48% higher than the Disconnected Piled Raft (DPR). The VPR system significantly surpassed DPR, achieving 20 mm settlement at 580 kPa, a 12.91% improvement over DPR, which settled at 420 kPa. The Geogrid-Reinforced Piled Raft (GPR) system improved load distribution, showing a 54.83% increase in bearing capacity over DPR, reaching 600 kPa. Lastly, the Connected Piled Raft (CPR) proved more effective in reducing tilt than DPR, with a tilt reduction factor (TRF) of 0.25 compared to DPR\\u0026rsquo;s 0.55, limiting tilt to 0.3 degrees.\\u003c/p\\u003e\",\"manuscriptTitle\":\"An Experimental Assessment of Piled Raft Foundation Under Axial and Eccentric Loading in the Scenario of Granular Soil Conditions\",\"msid\":\"\",\"msnumber\":\"\",\"nonDraftVersions\":[{\"code\":1,\"date\":\"2024-11-28 17:40:18\",\"doi\":\"10.21203/rs.3.rs-5432554/v1\",\"editorialEvents\":[{\"type\":\"communityComments\",\"content\":0}],\"status\":\"published\",\"journal\":{\"display\":true,\"email\":\"info@researchsquare.com\",\"identity\":\"researchsquare\",\"isNatureJournal\":false,\"hasQc\":true,\"allowDirectSubmit\":true,\"externalIdentity\":\"\",\"sideBox\":\"\",\"snPcode\":\"\",\"submissionUrl\":\"/submission\",\"title\":\"Research Square\",\"twitterHandle\":\"researchsquare\",\"acdcEnabled\":true,\"dfaEnabled\":false,\"editorialSystem\":\"\",\"reportingPortfolio\":\"\",\"inReviewEnabled\":false,\"inReviewRevisionsEnabled\":true}}],\"origin\":\"\",\"ownerIdentity\":\"5504fb88-6547-46a9-838e-bde05780c251\",\"owner\":[],\"postedDate\":\"November 28th, 2024\",\"published\":true,\"recentEditorialEvents\":[],\"rejectedJournal\":[],\"revision\":\"\",\"amendment\":\"\",\"status\":\"posted\",\"subjectAreas\":[],\"tags\":[],\"updatedAt\":\"2025-10-27T14:20:19+00:00\",\"versionOfRecord\":[],\"versionCreatedAt\":\"2024-11-28 17:40:18\",\"video\":\"\",\"vorDoi\":\"\",\"vorDoiUrl\":\"\",\"workflowStages\":[]},\"version\":\"v1\",\"identity\":\"rs-5432554\",\"journalConfig\":\"researchsquare\"},\"__N_SSP\":true},\"page\":\"/article/[identity]/[[...version]]\",\"query\":{\"redirect\":\"/article/rs-5432554\",\"identity\":\"rs-5432554\",\"version\":[\"v1\"]},\"buildId\":\"qtupq5eGEP_6zYnWcrvyt\",\"isFallback\":false,\"isExperimentalCompile\":false,\"dynamicIds\":[84888],\"gssp\":true,\"scriptLoader\":[]}","source_license":"CC-BY-4.0","license_restricted":false}