Study on the Mixing Properties of Bamboo Fiber and Loose Soil

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In order to solve the problem of single -slope pine loose reinforcement methods, and the limitation in chemistry and biological methods, and bamboo fiber is used to strengthen the loose soil. Through direct shearing tests and scanning electron microscopes, the mechanical characteristics and interaction mechanism of bamboo fiber and loose soil reinforcement are studied. The research results show that the fiber and loose soil is mainly connected through micro-particles. The closer to the fiber, the more the number of micro -grains; with the increasing of fiber content, the increase in the shear strength of the mixture is increased sharply after the shear strength increases first, and then slightly decreased; appropriate amount of micro -mucous particles can significantly enhance the shear strength of the mixture, and excessive micro -mucous particles can cause the intensity of the mixture to decrease. The results of the research can provide theoretical reference for engineering projects such as road slope, building slope, tail mining, and artificial pile of earth soil. Physical sciences/Engineering/Civil engineering Physical sciences/Materials science bamboo fiber slope loose soil reinforcement properties Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 1 Introduction The stability of slopes is paramount in ensuring the safety of both life and property, particularly in the construction of roadbeds, tunnels, and bridges [ 1 – 3 ] . In recent years, the rapid pace of urbanization has elevated slope stability to a critical issue that necessitates urgent exploration and effective action by the geoscientific and soil engineering academic community. Currently, the performance of geotechnical engineering materials has garnered significant attention, with soil improvement being a prominent area of focus. The prevalent methods for soil improvement encompass physical, chemical, and biological approaches. The physical method involves incorporating materials with certain strength characteristics into the soil to enhance its tensile resistance [ 4 ] . The chemical method entails adding substances that undergo chemical reactions with the soil to improve its mechanical properties [ 5 ] . The biological method, on the other hand, utilizes microorganisms to alter the physicochemical properties of the soil, thereby enhancing its engineering performance [ 6 ] . Recently, numerous scholars have advanced soil improvement techniques through physical, chemical, and biological methods. In the realm of physical methods, Arabani M. mixed wheat fiber and nano-pusher [ 7 ] , as well as palm fiber [ 8 ] , into the soil as test materials. Zachariah P.J. employed sugar cane fiber as an enhancement for gravel [ 9 ] , while plant root systems have been used as soil reinforcement materials [ 10 ] . Ramkrishnan R. utilized sword linen fiber for soil reinforcement [ 11 ] . These studies have collectively shown varying degrees of improvement in soil strength indicators such as compressive and shear resistance. In terms of chemical methods, Srijan added silicate cement and lime to soft soil to effectively bolster its strength [ 12 ] . CHEN L.H. applied a chemical grouting method to reinforce bridge (culvert) soil bodies, enhancing their compressive performance [ 13 ] . Yuxin W. repaired foundations using a chemical method involving the decomposition of calcium carbonate with urea [ 14 ] . As for biological methods, Fatehi H. incorporated a tentinic and sodium tentinol biological polymer extracted from milk into sandy soil. The microorganisms studied for soil reinforcement mainly precipitation carbonate minerals through their enzymes and metabolic activities [ 15 – 17 ] . Regarding slope loose body reinforcement, more emphasis has been placed on artificial excavation or chemical methods (such as cement mixing reinforcement in chemical methods). However, chemical methods are costly, alter the soil's nature, pollute groundwater and the soil environment, and lack environmental friendliness. Furthermore, biometric control is challenging, and the reinforcement effect is often suboptimal. In physical methods, soil improvement materials are predominantly glass fiber, sword and linen fiber, sugar cane residue, palm fiber, wheat fiber, etc., with bamboo fiber being relatively understudied. The reinforcement effect and the bonding mechanism between the loose body and bamboo fiber remain unexplored. To address this gap, this study selects bamboo fiber as an improvement material for slope loose soil. Bamboo fiber is a plant fiber material known for its high tensile strength, durability after preprocessing, lightness, environmental friendliness, and ease of availability. This study employs a direct shear test to investigate the mechanical characteristics and interaction mechanisms between bamboo fiber and slope loose soil reinforcement. Additionally, the microstructure of the soil body is analyzed using scanning electron microscopy. The findings of this research can provide a theoretical framework for engineering projects such as road slopes, building slopes, tailings dams, and artificial earth embankments. 2 Materials and Preparation 2.1 Raw Materials The core materials of this study consist of bamboo fiber and loose soil collected from slope areas. The loose soil samples (S) were obtained from highway slopes in southwestern China. These samples underwent a series of processing steps, including washing with water, drying, grinding, and sieving, to obtain their particle size distribution curve, as depicted in Fig. 1 . Based on this particle size distribution curve, the distribution characteristics of the soil particles were calculated and presented in Fig. 1 . In strict adherence to the authoritative guidelines outlined in the "Specification for Soil Test of Highway Engineering" (JTGD40-2007), an exhaustive series of fundamental physical property tests were meticulously conducted on the loose soil samples. The comprehensive results of these tests are systematically presented in Table 1 , ensuring a clear and accurate representation of the soil characteristics as per industry standards and practices. Table 1 Basic Physical Parameters of Soil Samples Liquid Limit/% Plastic Limit /% Plasticity Index/% Optimum Moisture Content /% Maximum Dry Density/g/cm³ 36.5 23 13.5 21 1.722 Bamboo fiber (BF), sourced from southwest China and derived from Moso bamboo, undergoes pretreatment prior to use, which encompasses impurity removal, cleaning, drying, and pulverization, among other processes. The mechanical property parameters are presented in Table 2 below Table 2 Mechanical Property Parameters of Bamboo Fiber Fiber Length/mm Fiber Bundle Diameter/mm Density /g/cm³ Moisture Content /% Tensile Strength/MPa Modulus /GPa Elongation at Break/% 20-60mm 0.16–0.28 1.15–1.30 3–8 292–305 20–31 1.3–1.5 2.2 Material Preparation Material Preparation and Readiness: In accordance with the meticulously planned experimental design, bamboo fiber and test soil samples were precisely weighed in accordance with predetermined proportions. To guarantee suitable lengths and diameters conducive to effective mixing, the bamboo fiber underwent rigorous shearing and screening processes. Specifically, the bamboo fiber was meticulously cut to lengths ranging from 1 to 2 centimeters, and a high-precision vernier caliper was employed to meticulously select fibers with diameters within the range of 0.22 ± 0.05 millimeters. Mixing Procedure: The soil samples and bamboo fibers were weighed accurately to 0.1 grams. The bamboo fibers were incorporated into the soil samples, and a predetermined amount of water was sprayed onto the mixture. Manual stirring was employed to thoroughly blend the components until the bamboo fibers were uniformly distributed throughout the soil samples, with no visible agglomeration or clustering. The mixed soil samples were then sealed in plastic wrap and allowed to sit for one full day. For brevity, the mixture of bamboo fibers and loose slope materials is hereinafter referred to as the "composite mixture." 3 Experiment design and procedures 3.1 Experimental Design To investigate the reinforcement performance of bamboo fiber content on loose materials, eight experimental groups, namely BFS-0 to BFS-7, were established. Within these groups, the bamboo fiber content was varied at 0.0%, 0.5%, 1%, 1.5%, 2.0%, 3.0%, 4.0%, and 5.0%, respectively, with a consistent water content of 21% across all groups. The particle size distribution of the test soil samples was configured according to Fig. 1 , with particles below 0.075mm accounting for 5.25%, those between 0.075mm and 0.25mm for 11.53%, between 0.25mm and 0.5mm for 15.32%, between 0.5mm and 1.0mm for 26.61%, between 1.0mm and 2.0mm for 28.55%, and particles above 2.0mm for 12.74%. To assess the impact of varying clay content on the strength of the mixture, five additional experimental groups, specifically BFS-8 to BFS-12, were set up. In these groups, the bamboo fiber content was fixed at 1%, and the water content was maintained at 21%. The mass percentage of clay particles below 0.075mm was varied among the groups, set at 6%, 11%, 16%, 21%, and 26%, respectively. 3.2 Direct Shear Test Direct shear tests were conducted on the mixtures using the "consolidated quick shear" method. The testing instrument employed was the "ZJ-type strain-controlled direct shear apparatus" manufactured by Nanjing Soil Instrument Factory in China. During the testing, a stepped loading method was adopted for loading and consolidation of the samples, with the sequence of loads being 0 kPa → 50 kPa → 100 kPa → 200 kPa → 300 kPa → 400 kPa, and each load level being maintained for approximately 1 minute. During the consolidation process, the consolidation deformation was measured and recorded every hour. The criterion for identifying consolidation stability was that the vertical deformation did not exceed 0.005 mm per hour. Once consolidation was completed, the direct shear test was initiated with a shear rate of 0.8 mm/min. The dial gauge reading of the dynamometer was recorded every minute until shear failure occurred. 4 Experiment results and Analysis 4.1 Results and Analysis about Bamboo Fiber Content 4.1.1 Experimental Results During the execution of the direct shear tests, meticulous records were maintained of the vertical pressures applied and the dial gauge readings obtained from the dynamometer. The shear stress was computed utilizing the formula τ = (C × R) / A × 10, where C signifies the calibration coefficient of the dynamometer (specifically, 1.471 N/0.001 mm), R denotes the dynamometer reading (in units of 0.01 mm), and A represents the area of the test specimen (30 cm²). Shear stresses corresponding to various vertical pressures were determined, and the resultant data are graphically depicted in Fig. 2 . Figure 3 displays the shear stress values of various samples (ranging from BFS-0 to BFS-7) subjected to different vertical pressures. These data points, distinguished by their unique colors and shapes, vividly illustrate the shear stress magnitudes of each sample at specific pressure levels. Notably, these data points do not arrange themselves in a perfect straight line but exhibit a certain degree of scatter. Nonetheless, despite this scatter, a discernible trend emerges from the data points. To augment the precision and dependability of the experimental findings and address the issue of data dispersion, a linear fitting methodology was utilized to smooth out the discrete data points. This approach facilitated the derivation of the linear relationship between shear stress and vertical pressure for each sample. As depicted in Fig. 4 , all fitting curves adhere to a linear function. According to Coulomb's theorem, the slope of these fitting curves signifies the internal friction angle, while the intercept represents the cohesion. These two parameters collectively constitute the shear strength characteristics of the composite material. The fitting results reveal that the slopes for Groups BFS-0 through BFS-7 are 0.0474, 0.061, 0.0635, 0.0707, 0.075, 0.0765, 0.0772, and 0.0767, respectively. Concurrently, the intercepts are 2.0104, 2.452, 4.34, 5.197, 6.374, 6.374, 6.472, and 6.227, respectively. Notably, both the intercepts and slopes of Groups BFS-1 to BFS-7 exhibit significant increases compared to those of Group BFS-0, indicating a substantial enhancement. This observation underscores the notable impact of incorporating bamboo fibers on augmenting the strength of the granular material. To delve deeper into the reinforcement performance of bamboo fiber content on loose soil, based on the linear fitting results obtained for Groups BFS-0 through BFS-7, the relationship between two crucial soil strength indicators—cohesion and internal friction angle—and the variation in bamboo fiber content is graphically illustrated in Fig. 5 . The data presented in Fig. 5 demonstrate that cohesion increases overall with the increment of bamboo fiber content. Specifically: The cohesion of Group BFS-0 is the lowest, while Groups BFS-1 to BFS-7 exhibit significant enhancements in cohesion, indicating that bamboo fiber can markedly improve the cohesion of loose materials. Notably, within the bamboo fiber content range of 0.5–2%, cohesion increases drastically, with the most pronounced increase occurring between 1% and 2%, demonstrating its strong reinforcing effect. However, when the bamboo fiber content exceeds 2% and increases to 5%, cohesion decreases slightly, suggesting a gradual weakening of its reinforcing effect. As a crucial indicator of the frictional characteristics between soil particles, the internal friction angle also increases overall with the addition of bamboo fiber content. Group BFS-0 has the smallest internal friction angle of 25.2°, while it gradually increases from Group BFS-1 onwards, reaching 31.4° in Group BFS-1, which is significantly higher than that of Group BFS-0. With the continued increase in bamboo fiber content, the internal friction angles of Groups BFS-2 to BFS-7 increase to varying degrees, with Group BFS-7 (bamboo fiber content of 5.0%) achieving the highest value of 37.7°. When the bamboo fiber content increases from 1–2%, the internal friction angle exhibits substantial growth; however, when it increases from 2–5%, the growth rate diminishes, and the trend slows down. In summary, the incorporation of bamboo fiber positively enhances the shear strength characteristics of soil. 4.1.2 Analysis of Experimental Results The experimental results clearly demonstrate that the incorporation of bamboo fibers has a significant impact on the cohesion and internal friction angle of soil, with these effects manifesting not only in the enhancement of macroscopic mechanical properties but also in providing deeper insights into the micro-level interaction mechanisms between bamboo fibers and soil structure. Cohesion, as the internal force that resists tensile or shear failure in soil, is primarily provided by the interactions between soil particles and cementing materials. The introduction of bamboo fibers reconstructs the soil structure at the micro-level, thereby influencing the exertion of these forces. Bamboo fibers, with their natural characteristics of high strength and high modulus, play the role of reinforcing bars in loose soil, enabling physical connections within the soil. At lower fiber contents, they primarily function as connectors in localized regions; as the content increases, they form a network structure within the soil, extending the physical connections to the entire space and thus enhancing cohesion. However, when the fiber content exceeds a certain limit, due to the finite number of binding particles in the soil, the bonding effect between the fibers and the soil no longer increases but instead exhibits a slight weakening trend. The internal friction angle serves as a critical parameter reflecting the frictional characteristics between soil particles. The elongated structure of bamboo fibers forms a "network" or "skeleton" within the soil, enhancing the overall stability of the soil and increasing the sliding resistance between particles. When the soil is subjected to shear forces, the fiber network can absorb and disperse the shear forces, thereby improving the shear strength and internal friction angle of the soil. In summary, the addition of bamboo fibers alters the structural characteristics of loose materials and the interaction mechanisms between particles and fibers at the micro-level. Within a certain range of fiber content, it enhances the cohesion and internal friction angle of the soil. However, beyond this range, a slight weakening trend is observed. 4.2 Results and Analysis about Clay Content 4.2.1 Experimental Results In the direct shear tests conducted to investigate the impact of varying clay content on the mixture's strength, the calibration coefficient of the force-measuring instrument, as well as the test area utilized in the computation of shear stress, were maintained as constants throughout the experimental procedure. The results obtained through these computations are depicted in Fig. 6 . Figure 6 meticulously depicts the shear stress values of samples containing varying clay percentages, specifically ranging from BFS-8 to BFS-12, under diverse vertical pressure conditions. Each sample's data points are distinctly represented through unique colors and symbols, thereby enabling a clear visualization of the shear stress magnitudes associated with different clay contents under specific pressures. Despite the presence of slight data dispersion, discernible trends emerge from these observations. To augment the precision and credibility of the experimental findings and to address the inherent variability in the data points, a rigorous linear fitting approach was adopted to analyze the discrete data. Notably, all the fitting curves adhere to a first-degree linear function. The outcomes of this analysis are concisely presented in Fig. 7 . To conduct a deeper analysis of the impact of clay content on the mechanical characteristics of the mixture, and drawing upon the linear fitting results obtained from Groups BFS-8 to BFS-12, a linear plot is employed to elucidate the relationship between soil strength indices—specifically cohesion and internal friction angle—and the varying clay content. This comprehensive representation is vividly depicted in Fig. 8 . The experimental data and the corresponding result plots clearly indicate that as the clay content within the mixture undergoes an increase, both cohesion and internal friction angle display discernible patterns of variation. Specifically, as the clay content rises from 6–16%, there is a gradual increase observed in both the cohesion and internal friction angle of the mixture. However, it is noteworthy that the rates of growth for both these parameters gradually diminish during this period. At a clay content of precisely 16%, the cohesion of the mixture attains its maximum value. Conversely, when the clay content surpasses 16% and continues to increase, both the cohesion and internal friction angle of the mixture exhibit a gradual decline. 4.2.2 Analysis of Experimental Results Based on the aforementioned experimental findings, we can deduce the following patterns concerning the influence of clay content on the shear strength of the mixture: At relatively low clay contents, an increase in clay content leads to a gradual enhancement in the shear strength of the mixture. This enhancement stems from the ability of an appropriate quantity of clay particles to fill the interstitial spaces between bamboo fibers, soil particles, and among soil particles themselves. This filling action augments the bonding force between bamboo fibers and soil, as well as among soil particles, thereby bolstering the cohesive force and friction force of the mixture. When the clay content attains a specific critical threshold, the shear strength of the mixture achieves its peak. At this juncture, the interplay between loose particles and bamboo fibers attains an optimal state, fostering the formation of a relatively stable structural system. Beyond this critical clay content, the shear strength of the mixture commences a decline. This decrement arises due to the viscosity increase induced by an excessive amount of clay particles, which diminishes the friction force and bite force between particles. Furthermore, an abundance of clay particles may result in the formation of excessive cementing materials, rendering the mixture more prone to damage during shear processes. In light of the aforementioned experimental results, the pattern of strength variation under the influence of clay content can be categorized into three distinct stages: the joint reinforcement stage, the optimal strengthening stage, and the soil weakening stage. The joint reinforcement stage pertains to the process wherein the bonding force between fibers and soil, as well as among soil particles, undergoes concurrent augmentation. The optimal strengthening stage signifies the phase at which the mixture attains its utmost strength at the critical clay content. Conversely, the soil weakening stage denotes the process wherein the bonding force between fibers and soil ceases to increase, while the bonding force among soil particles progressively weakens. 5 Microscopic Morphology Analysis To comprehensively analyze the characteristics of soil particle distribution, pore structure, bamboo fiber composition, texture, and other pertinent features within the mixture, and to elucidate the macroscopic mechanical behavior, Scanning Electron Microscopy (SEM), specifically a Desktop Scanning Electron Microscope manufactured by Phenom World (model: Phenom ProX, origin: Netherlands), was utilized to examine the microscopic morphology of sheared specimens. Figure 9 showcases the SEM images of the sheared mixture, offering a detailed visualization of its structural features. Under a magnification of 400x in Scanning Electron Microscope (SEM) images (a), bamboo fiber bundles are composed of multiple single fibers, exhibiting a distinct multi-filament morphology. The single fibers are observed to branch and intertwine among themselves. The diameter range of these single fibers, as indicated in the images, spans from 6um to 26um, highlighting their relatively minute size. At a magnification of 2500x (b), the soil appears as a collection of particles of varying shapes and sizes, which are cohesively bound together through physical and chemical interactions, forming a porous and rugged surface structure. Within a proximity of approximately 50um around the fibers, the soil particles are notably smaller, ranging in size from 4-42um, which is less than 0.075mm. This suggests that the vicinity of the fibers is predominantly populated by smaller micro-clay particles. SEM images (c) captured at a magnification of 4500x reveal that following the shear test, the fibers and soil particles have undergone displacement, resulting in pores approximately 13um in size and inter-fiber distances of about 9um. These dimensions fall within the range of clay particles, indicating that the pores are primarily a result of the displacement of clay particles or their relative displacement to the fibers. In these SEM images, irregularly shaped and sized soil particle residues can be clearly seen adhering to the surface of the bamboo fibers. This indicates that during the pullout process, there was significant interaction between the soil particles and the bamboo fibers, causing some soil particles to be stripped and attached to the fibers. Additionally, minute scratches and wear marks are evident on the surface of the bamboo fibers, potentially due to friction and scraping of soil particles against the fiber surface during pullout. The presence of wear marks suggests that the bamboo fibers underwent a degree of plastic deformation and wear during the pullout process, further corroborating the strong bonding between bamboo fibers and soil. At a magnification of 12000x (d), the fiber surface exhibits a concave-convex morphology, providing favorable conditions for the embedding of clay binders. The clay particle diameter on the fiber surface ranges approximately from 2-6um, with even finer particle sizes observed. In the SEM images, the bonding interface between bamboo fibers and soil is also discernible. At this interface, soil particles can be seen tightly enveloping the bamboo fibers, forming a structure akin to "anchoring," which enhances the physical connection between bamboo fibers and soil. Furthermore, minute protrusions and depressions formed by soil particles on the surface of bamboo fibers are visible, increasing the contact area and friction force between them. In summary, SEM images demonstrate that the area surrounding the fibers is predominantly filled with micro-clay particles with diameters less than 0.075mm. Moreover, as one approaches the fiber surface, the clay particle diameters decrease. Therefore, the connection between fibers and soil is primarily facilitated by micro-clay particles. Based on this characteristic, a structural model of the mixture and its failure mechanism was established, as depicted in Fig. 10 . The composite mixture structure model elucidates that bamboo fibers and granular materials are primarily interconnected via micro-clay particles, with a predominant distribution of these particles observed on the bamboo fiber surface. The proximity to bamboo fibers correlates positively with the abundance of micro-clay particles. The direct shear test results, conducted across varying clay contents, effectively corroborate this model. During the reinforcement phase of the composite, an augmentation in clay content significantly enhances the adhesion between bamboo fibers and soil particles, as well as the cohesion among larger soil aggregates. At the optimal reinforcement stage, where the quantity of bamboo fibers and larger soil particles remains constant, the clay content achieves an optimal balance with these components, thereby maximizing the composite mixture's strength. Conversely, in the soil weakening phase, as the clay content continues to rise, the maximum adhesion between bamboo fibers and soil is attained, with no further augmentation possible. However, an increase in clay particles among larger soil aggregates diminishes their supportive role and reduces the inter-particle friction, consequently weakening the overall composite strength. In summation, the distribution of micro-clay particles exerts a notable influence on the shear strength of the composite mixture. A moderate quantity of micro-clay particles can augment the shear strength, whereas an excessive amount, post-peak, will attenuate it. 6 Conclusions The present study aims to explore the mechanical properties of bamboo fiber-reinforced loose soil mixtures, providing scientific support for the reinforcement of loose soil slopes. Through direct shear tests and microscopic analysis, we conducted an in-depth investigation into the effects of bamboo fiber content and clay content on the shear strength of the mixtures. The research findings reveal that the incorporation of bamboo fibers significantly enhances the cohesion and internal friction angle of loose soil. As the bamboo fiber content increases, the shear strength of the mixtures exhibits an initial sharp increase followed by a slight decrease, with the most pronounced enhancement observed at bamboo fiber contents ranging from 0.5–2%. Additionally, clay content exerts a significant influence on the strength of the mixtures; an appropriate amount of clay particles notably augments the shear strength, whereas an excess leads to a decline in strength. The variation in strength can be categorized into three stages: co-strengthening, optimal reinforcement, and soil weakening. Microscopic image analysis confirms that the fibers and loose soil are primarily connected through micro-clay particles, with a dense distribution of micro-clay particles on the surface of the bamboo fibers, and an increasing number of these particles as their proximity to the fibers decreases. Based on this observation, we established a structural model for the mixtures and their failure modes, which effectively explains the variation in mixture strength under different clay contents. The innovative aspects of this study lie in: systematically investigating the effects of bamboo fiber content and clay content on the mechanical properties of the mixtures, thereby filling a research gap; combining macro-mechanical tests with microscopic analysis to uncover the microscopic mechanisms underlying the reinforcement of loose soil by bamboo fibers; establishing a structural model; and proposing three stages of mixture strength variation. Declarations Data Availability The datasets generated during and/or analysed during the current study are of significant importance for validating the research findings and enabling future research endeavors in the relevant field. In accordance with the principles of open science and data sharing, the authors are committed to ensuring that these datasets are accessible to the research community. Therefore, the datasets generated during and/or analysed during the current study are available from the corresponding author on reasonable request. Researchers interested in obtaining these datasets should contact the corresponding author, who will provide further instructions and conditions for data access, ensuring compliance with any relevant data protection and privacy regulations. The authors encourage responsible use and citation of the data in any subsequent research publications. References Israr M K ,Shuhong W ,Pengyu W , et al. Soil slope analysis to develop useful correlations in saturated and unsaturated conditions. J . Proceedings of the Institution of Civil Engineers - Forensic Engineering.1-10(2022). Wang Wei. Stability Analysis of High Loose Deposit Slope Based on Distinict Element Method. D . 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Sustainable material as a column filler in soft clay bed reinforced with encased column: numerical analysis. J . Scientific Reports.15 (1),1650-1650(2025). Chen L H ,Wang W D . Chemical Grouting Technique to Strengthen the Bridge (Culvert) Abutment Soft Ground Projects. J . Applied Mechanics and Materials., 1975,2065-2069( 2012). Yuxin W ,B J A ,Nicolas S , et al. Geophysical monitoring and reactive transport modeling of ureolytically-driven calcium carbonate precipitation. J . Geochemical transactions. 12 (1), 7(2011). Fatehi H ,Abtahi M S ,Hashemolhosseini H , et al. A novel study on using protein based biopolymers in soil strengthening. J . Construction and Building Materials.167 ,813-821(2018). Surabhi J ,Chaolin F ,Varenyam A . A critical review on microbial carbonate precipitation via denitrification process in building materials. J . Bioengineered. 12 (1), 7529-7551(2021). Haystead J . The optimization of microbial induced calcium carbonate precipitation in soil improvement using engineered bacteria. J . Access Microbiology.1 (1A),(2019). 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. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-5951765","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":415544204,"identity":"271b2d1e-3a91-4828-bfbc-3e0101373941","order_by":0,"name":"Honggang Ding","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA90lEQVRIiWNgGAWjYBACfmbGhgMfKv7b8TMwN8AEDfBqkWxvbnw44wxzsmQDI5FaDM4cbzbmbGNm3HCAWC0MNxLbpBnb2JiNjx9sk2CosU5sYG/eBmTcwamDcQZQS8E5Hj6zM4lALcfSExt4jpUBGc9wamGWAGqZUSbBbHYAqIWx4XBig0SOGYiBUwsbSAsPmwHj5v6HUC3yb/Br4eE52GzM05bAuEECbgsPfi0S7I2gQD6QLHHjYbNFwrF04zaetGIgA7cW+8PsD4BRecCOvz/54I0PNday/eyHNwIZuLWgggQGZgY2CIN4wEyC2lEwCkbBKBgpAAD4slfFl6c1VwAAAABJRU5ErkJggg==","orcid":"","institution":"","correspondingAuthor":true,"prefix":"","firstName":"Honggang","middleName":"","lastName":"Ding","suffix":""},{"id":415544205,"identity":"1f02e529-64b3-4036-8551-419326d4b6bb","order_by":1,"name":"Yanjie Zhang","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Yanjie","middleName":"","lastName":"Zhang","suffix":""},{"id":415544206,"identity":"00299b2f-79a1-41d5-99f9-869d0738c9c9","order_by":2,"name":"Ao Zuo","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Ao","middleName":"","lastName":"Zuo","suffix":""},{"id":415544207,"identity":"3636d7a8-46fb-40af-b283-b8ccc4f9d0c0","order_by":3,"name":"Liping Zhou","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Liping","middleName":"","lastName":"Zhou","suffix":""}],"badges":[],"createdAt":"2025-02-03 14:23:35","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-5951765/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-5951765/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":76294088,"identity":"90bca527-4a6a-46e9-8b72-7af5b905ca0f","added_by":"auto","created_at":"2025-02-14 12:53:24","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":16038,"visible":true,"origin":"","legend":"\u003cp\u003eParticle Size Distribution Curve\u003c/p\u003e","description":"","filename":"floatimage1.png","url":"https://assets-eu.researchsquare.com/files/rs-5951765/v1/27d0ef17d658743b4874db9d.png"},{"id":76293800,"identity":"f69d0912-bcc4-4f17-8a23-7ee876174d71","added_by":"auto","created_at":"2025-02-14 12:45:24","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":82182,"visible":true,"origin":"","legend":"\u003cp\u003eBamboo Fiber（Source of Bamboo Fiber: The bamboo fiber is made from Mao bamboo, originating from southwestern China. The bamboo fiber used in this study was obtained through purchase.）\u003c/p\u003e","description":"","filename":"floatimage2.png","url":"https://assets-eu.researchsquare.com/files/rs-5951765/v1/97fa9de3fc4a40e25f88b2d5.png"},{"id":76293810,"identity":"29c3e1b2-ce90-4e1c-b29a-3ca575f1aab2","added_by":"auto","created_at":"2025-02-14 12:45:24","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":49426,"visible":true,"origin":"","legend":"\u003cp\u003eExperimental Results of Composite Strength under Different Fiber Contents\u003c/p\u003e","description":"","filename":"floatimage3.png","url":"https://assets-eu.researchsquare.com/files/rs-5951765/v1/c55f5cfd46427e354cdadd85.png"},{"id":76295228,"identity":"dbb95470-fa99-4d41-8b29-b40c22582aef","added_by":"auto","created_at":"2025-02-14 13:01:24","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":69374,"visible":true,"origin":"","legend":"\u003cp\u003eFitting Curves of Experimental Results for Various Fiber Contents\u003c/p\u003e","description":"","filename":"floatimage4.png","url":"https://assets-eu.researchsquare.com/files/rs-5951765/v1/d434279aa139a59b72a78e51.png"},{"id":76293798,"identity":"1f37d878-1593-4c88-b155-18b520e22138","added_by":"auto","created_at":"2025-02-14 12:45:24","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":32046,"visible":true,"origin":"","legend":"\u003cp\u003eRelationship Between Strength Indices of the Mixture under Different Fiber Contents\u003c/p\u003e","description":"","filename":"floatimage5.png","url":"https://assets-eu.researchsquare.com/files/rs-5951765/v1/c5174b472fd199943b8aa01f.png"},{"id":76293797,"identity":"27f14355-3c8b-40b9-a938-d5a9f635fbc1","added_by":"auto","created_at":"2025-02-14 12:45:23","extension":"png","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":40914,"visible":true,"origin":"","legend":"\u003cp\u003eExperimental Results Based on Varying Clay Content Conditions\u003c/p\u003e","description":"","filename":"floatimage6.png","url":"https://assets-eu.researchsquare.com/files/rs-5951765/v1/074af4060bd91d3aac08886a.png"},{"id":76294097,"identity":"27b4cee0-1549-4344-81ad-a07109df36d6","added_by":"auto","created_at":"2025-02-14 12:53:25","extension":"png","order_by":7,"title":"Figure 7","display":"","copyAsset":false,"role":"figure","size":44306,"visible":true,"origin":"","legend":"\u003cp\u003eLinear Fit Results Based on Varying Clay Content Conditions\u003c/p\u003e","description":"","filename":"floatimage7.png","url":"https://assets-eu.researchsquare.com/files/rs-5951765/v1/d004c602a60e5e72ad2fe7a0.png"},{"id":76294087,"identity":"e9991fd7-8943-48ec-b6f5-fe329bfaa118","added_by":"auto","created_at":"2025-02-14 12:53:24","extension":"png","order_by":8,"title":"Figure 8","display":"","copyAsset":false,"role":"figure","size":32945,"visible":true,"origin":"","legend":"\u003cp\u003eVariation of Strength with Clay Content\u003c/p\u003e","description":"","filename":"floatimage8.png","url":"https://assets-eu.researchsquare.com/files/rs-5951765/v1/f2badf95ce5c52b9ace42662.png"},{"id":76293812,"identity":"fbf149b3-1a8c-4560-a59d-2b4161dcc56a","added_by":"auto","created_at":"2025-02-14 12:45:24","extension":"png","order_by":9,"title":"Figure 9","display":"","copyAsset":false,"role":"figure","size":1847872,"visible":true,"origin":"","legend":"\u003cp\u003eScanning Electron Microscope Image\u003c/p\u003e","description":"","filename":"9.png","url":"https://assets-eu.researchsquare.com/files/rs-5951765/v1/3fdff49cca4a68b89f106c2d.png"},{"id":76293816,"identity":"6cde9c54-ed25-4ee6-bd2f-076f14b71f49","added_by":"auto","created_at":"2025-02-14 12:45:24","extension":"png","order_by":10,"title":"Figure 10","display":"","copyAsset":false,"role":"figure","size":181744,"visible":true,"origin":"","legend":"\u003cp\u003eStructure and Failure Model of the Composite Mixture\u003c/p\u003e","description":"","filename":"floatimage13.png","url":"https://assets-eu.researchsquare.com/files/rs-5951765/v1/70e69e53937a241d67cd17a2.png"},{"id":77557309,"identity":"7c065948-f1a3-4197-bd1a-c32ab0d03c1e","added_by":"auto","created_at":"2025-03-03 06:04:18","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":3403112,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-5951765/v1/9f3c4fda-862d-45fd-b146-80e57c2f1bae.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Study on the Mixing Properties of Bamboo Fiber and Loose Soil","fulltext":[{"header":"1 Introduction","content":"\u003cp\u003eThe stability of slopes is paramount in ensuring the safety of both life and property, particularly in the construction of roadbeds, tunnels, and bridges \u003csup\u003e[\u003cspan additionalcitationids=\"CR2\" citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]\u003c/sup\u003e. In recent years, the rapid pace of urbanization has elevated slope stability to a critical issue that necessitates urgent exploration and effective action by the geoscientific and soil engineering academic community. Currently, the performance of geotechnical engineering materials has garnered significant attention, with soil improvement being a prominent area of focus. The prevalent methods for soil improvement encompass physical, chemical, and biological approaches. The physical method involves incorporating materials with certain strength characteristics into the soil to enhance its tensile resistance\u003csup\u003e[\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]\u003c/sup\u003e. The chemical method entails adding substances that undergo chemical reactions with the soil to improve its mechanical properties\u003csup\u003e[\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]\u003c/sup\u003e. The biological method, on the other hand, utilizes microorganisms to alter the physicochemical properties of the soil, thereby enhancing its engineering performance \u003csup\u003e[\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eRecently, numerous scholars have advanced soil improvement techniques through physical, chemical, and biological methods. In the realm of physical methods, Arabani M. mixed wheat fiber and nano-pusher \u003csup\u003e[\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]\u003c/sup\u003e, as well as palm fiber \u003csup\u003e[\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]\u003c/sup\u003e, into the soil as test materials. Zachariah P.J. employed sugar cane fiber as an enhancement for gravel \u003csup\u003e[\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]\u003c/sup\u003e, while plant root systems have been used as soil reinforcement materials \u003csup\u003e[\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]\u003c/sup\u003e. Ramkrishnan R. utilized sword linen fiber for soil reinforcement \u003csup\u003e[\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]\u003c/sup\u003e. These studies have collectively shown varying degrees of improvement in soil strength indicators such as compressive and shear resistance. In terms of chemical methods, Srijan added silicate cement and lime to soft soil to effectively bolster its strength \u003csup\u003e[\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]\u003c/sup\u003e. CHEN L.H. applied a chemical grouting method to reinforce bridge (culvert) soil bodies, enhancing their compressive performance \u003csup\u003e[\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]\u003c/sup\u003e. Yuxin W. repaired foundations using a chemical method involving the decomposition of calcium carbonate with urea \u003csup\u003e[\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]\u003c/sup\u003e. As for biological methods, Fatehi H. incorporated a tentinic and sodium tentinol biological polymer extracted from milk into sandy soil. The microorganisms studied for soil reinforcement mainly precipitation carbonate minerals through their enzymes and metabolic activities \u003csup\u003e[\u003cspan additionalcitationids=\"CR16\" citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eRegarding slope loose body reinforcement, more emphasis has been placed on artificial excavation or chemical methods (such as cement mixing reinforcement in chemical methods). However, chemical methods are costly, alter the soil's nature, pollute groundwater and the soil environment, and lack environmental friendliness. Furthermore, biometric control is challenging, and the reinforcement effect is often suboptimal. In physical methods, soil improvement materials are predominantly glass fiber, sword and linen fiber, sugar cane residue, palm fiber, wheat fiber, etc., with bamboo fiber being relatively understudied. The reinforcement effect and the bonding mechanism between the loose body and bamboo fiber remain unexplored. To address this gap, this study selects bamboo fiber as an improvement material for slope loose soil. Bamboo fiber is a plant fiber material known for its high tensile strength, durability after preprocessing, lightness, environmental friendliness, and ease of availability. This study employs a direct shear test to investigate the mechanical characteristics and interaction mechanisms between bamboo fiber and slope loose soil reinforcement. Additionally, the microstructure of the soil body is analyzed using scanning electron microscopy. The findings of this research can provide a theoretical framework for engineering projects such as road slopes, building slopes, tailings dams, and artificial earth embankments.\u003c/p\u003e"},{"header":"2 Materials and Preparation","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003e2.1 Raw Materials\u003c/h2\u003e \u003cp\u003eThe core materials of this study consist of bamboo fiber and loose soil collected from slope areas. The loose soil samples (S) were obtained from highway slopes in southwestern China. These samples underwent a series of processing steps, including washing with water, drying, grinding, and sieving, to obtain their particle size distribution curve, as depicted in Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e. Based on this particle size distribution curve, the distribution characteristics of the soil particles were calculated and presented in Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eIn strict adherence to the authoritative guidelines outlined in the \"Specification for Soil Test of Highway Engineering\" (JTGD40-2007), an exhaustive series of fundamental physical property tests were meticulously conducted on the loose soil samples. The comprehensive results of these tests are systematically presented in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e, ensuring a clear and accurate representation of the soil characteristics as per industry standards and practices.\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\u003eBasic Physical Parameters of Soil Samples\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\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 \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLiquid Limit/%\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePlastic Limit\u0026nbsp;/%\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003ePlasticity\u0026nbsp;Index/%\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eOptimum Moisture Content\u0026nbsp;/%\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eMaximum Dry Density/g/cm\u0026sup3;\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e36.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e23\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e13.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e21\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.722\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\u003eBamboo fiber (BF), sourced from southwest China and derived from Moso bamboo, undergoes pretreatment prior to use, which encompasses impurity removal, cleaning, drying, and pulverization, among other processes. The mechanical property parameters are presented in Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e below\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eMechanical Property Parameters of Bamboo Fiber\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"7\"\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 \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFiber Length/mm\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eFiber Bundle Diameter/mm\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eDensity\u003c/p\u003e \u003cp\u003e/g/cm\u0026sup3;\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eMoisture Content\u003c/p\u003e \u003cp\u003e/%\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eTensile Strength/MPa\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eModulus\u003c/p\u003e \u003cp\u003e/GPa\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003eElongation at Break/%\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e20-60mm\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.16\u0026ndash;0.28\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.15\u0026ndash;1.30\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e3\u0026ndash;8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e292\u0026ndash;305\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e20\u0026ndash;31\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e1.3\u0026ndash;1.5\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003e2.2 Material Preparation\u003c/h2\u003e \u003cp\u003eMaterial Preparation and Readiness: In accordance with the meticulously planned experimental design, bamboo fiber and test soil samples were precisely weighed in accordance with predetermined proportions. To guarantee suitable lengths and diameters conducive to effective mixing, the bamboo fiber underwent rigorous shearing and screening processes. Specifically, the bamboo fiber was meticulously cut to lengths ranging from 1 to 2 centimeters, and a high-precision vernier caliper was employed to meticulously select fibers with diameters within the range of 0.22\u0026thinsp;\u0026plusmn;\u0026thinsp;0.05 millimeters.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eMixing Procedure: The soil samples and bamboo fibers were weighed accurately to 0.1 grams. The bamboo fibers were incorporated into the soil samples, and a predetermined amount of water was sprayed onto the mixture. Manual stirring was employed to thoroughly blend the components until the bamboo fibers were uniformly distributed throughout the soil samples, with no visible agglomeration or clustering. The mixed soil samples were then sealed in plastic wrap and allowed to sit for one full day. For brevity, the mixture of bamboo fibers and loose slope materials is hereinafter referred to as the \"composite mixture.\"\u003c/p\u003e \u003c/div\u003e"},{"header":"3 Experiment design and procedures","content":"\u003cdiv id=\"Sec6\" class=\"Section2\"\u003e \u003ch2\u003e3.1 Experimental Design\u003c/h2\u003e \u003cp\u003eTo investigate the reinforcement performance of bamboo fiber content on loose materials, eight experimental groups, namely BFS-0 to BFS-7, were established. Within these groups, the bamboo fiber content was varied at 0.0%, 0.5%, 1%, 1.5%, 2.0%, 3.0%, 4.0%, and 5.0%, respectively, with a consistent water content of 21% across all groups. The particle size distribution of the test soil samples was configured according to Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e, with particles below 0.075mm accounting for 5.25%, those between 0.075mm and 0.25mm for 11.53%, between 0.25mm and 0.5mm for 15.32%, between 0.5mm and 1.0mm for 26.61%, between 1.0mm and 2.0mm for 28.55%, and particles above 2.0mm for 12.74%.\u003c/p\u003e \u003cp\u003eTo assess the impact of varying clay content on the strength of the mixture, five additional experimental groups, specifically BFS-8 to BFS-12, were set up. In these groups, the bamboo fiber content was fixed at 1%, and the water content was maintained at 21%. The mass percentage of clay particles below 0.075mm was varied among the groups, set at 6%, 11%, 16%, 21%, and 26%, respectively.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec7\" class=\"Section2\"\u003e \u003ch2\u003e3.2 Direct Shear Test\u003c/h2\u003e \u003cp\u003eDirect shear tests were conducted on the mixtures using the \"consolidated quick shear\" method. The testing instrument employed was the \"ZJ-type strain-controlled direct shear apparatus\" manufactured by Nanjing Soil Instrument Factory in China.\u003c/p\u003e \u003cp\u003eDuring the testing, a stepped loading method was adopted for loading and consolidation of the samples, with the sequence of loads being 0 kPa \u0026rarr; 50 kPa \u0026rarr; 100 kPa \u0026rarr; 200 kPa \u0026rarr; 300 kPa \u0026rarr; 400 kPa, and each load level being maintained for approximately 1 minute.\u003c/p\u003e \u003cp\u003eDuring the consolidation process, the consolidation deformation was measured and recorded every hour. The criterion for identifying consolidation stability was that the vertical deformation did not exceed 0.005 mm per hour.\u003c/p\u003e \u003cp\u003eOnce consolidation was completed, the direct shear test was initiated with a shear rate of 0.8 mm/min. The dial gauge reading of the dynamometer was recorded every minute until shear failure occurred.\u003c/p\u003e \u003c/div\u003e"},{"header":"4 Experiment results and Analysis","content":"\u003cdiv id=\"Sec9\" class=\"Section2\"\u003e \u003ch2\u003e4.1 Results and Analysis about Bamboo Fiber Content\u003c/h2\u003e \u003cdiv id=\"Sec10\" class=\"Section3\"\u003e \u003ch2\u003e4.1.1 Experimental Results\u003c/h2\u003e \u003cp\u003eDuring the execution of the direct shear tests, meticulous records were maintained of the vertical pressures applied and the dial gauge readings obtained from the dynamometer. The shear stress was computed utilizing the formula τ = (C \u0026times; R) / A \u0026times; 10, where C signifies the calibration coefficient of the dynamometer (specifically, 1.471 N/0.001 mm), R denotes the dynamometer reading (in units of 0.01 mm), and A represents the area of the test specimen (30 cm\u0026sup2;). Shear stresses corresponding to various vertical pressures were determined, and the resultant data are graphically depicted in Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eFigure \u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e displays the shear stress values of various samples (ranging from BFS-0 to BFS-7) subjected to different vertical pressures. These data points, distinguished by their unique colors and shapes, vividly illustrate the shear stress magnitudes of each sample at specific pressure levels. Notably, these data points do not arrange themselves in a perfect straight line but exhibit a certain degree of scatter. Nonetheless, despite this scatter, a discernible trend emerges from the data points.\u003c/p\u003e \u003cp\u003eTo augment the precision and dependability of the experimental findings and address the issue of data dispersion, a linear fitting methodology was utilized to smooth out the discrete data points. This approach facilitated the derivation of the linear relationship between shear stress and vertical pressure for each sample. As depicted in Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e, all fitting curves adhere to a linear function. According to Coulomb's theorem, the slope of these fitting curves signifies the internal friction angle, while the intercept represents the cohesion. These two parameters collectively constitute the shear strength characteristics of the composite material.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eThe fitting results reveal that the slopes for Groups BFS-0 through BFS-7 are 0.0474, 0.061, 0.0635, 0.0707, 0.075, 0.0765, 0.0772, and 0.0767, respectively. Concurrently, the intercepts are 2.0104, 2.452, 4.34, 5.197, 6.374, 6.374, 6.472, and 6.227, respectively. Notably, both the intercepts and slopes of Groups BFS-1 to BFS-7 exhibit significant increases compared to those of Group BFS-0, indicating a substantial enhancement. This observation underscores the notable impact of incorporating bamboo fibers on augmenting the strength of the granular material.\u003c/p\u003e \u003cp\u003eTo delve deeper into the reinforcement performance of bamboo fiber content on loose soil, based on the linear fitting results obtained for Groups BFS-0 through BFS-7, the relationship between two crucial soil strength indicators\u0026mdash;cohesion and internal friction angle\u0026mdash;and the variation in bamboo fiber content is graphically illustrated in Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003e.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eThe data presented in Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003e demonstrate that cohesion increases overall with the increment of bamboo fiber content. Specifically:\u003c/p\u003e \u003cp\u003eThe cohesion of Group BFS-0 is the lowest, while Groups BFS-1 to BFS-7 exhibit significant enhancements in cohesion, indicating that bamboo fiber can markedly improve the cohesion of loose materials. Notably, within the bamboo fiber content range of 0.5\u0026ndash;2%, cohesion increases drastically, with the most pronounced increase occurring between 1% and 2%, demonstrating its strong reinforcing effect. However, when the bamboo fiber content exceeds 2% and increases to 5%, cohesion decreases slightly, suggesting a gradual weakening of its reinforcing effect.\u003c/p\u003e \u003cp\u003eAs a crucial indicator of the frictional characteristics between soil particles, the internal friction angle also increases overall with the addition of bamboo fiber content. Group BFS-0 has the smallest internal friction angle of 25.2\u0026deg;, while it gradually increases from Group BFS-1 onwards, reaching 31.4\u0026deg; in Group BFS-1, which is significantly higher than that of Group BFS-0. With the continued increase in bamboo fiber content, the internal friction angles of Groups BFS-2 to BFS-7 increase to varying degrees, with Group BFS-7 (bamboo fiber content of 5.0%) achieving the highest value of 37.7\u0026deg;. When the bamboo fiber content increases from 1\u0026ndash;2%, the internal friction angle exhibits substantial growth; however, when it increases from 2\u0026ndash;5%, the growth rate diminishes, and the trend slows down.\u003c/p\u003e \u003cp\u003eIn summary, the incorporation of bamboo fiber positively enhances the shear strength characteristics of soil.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec11\" class=\"Section3\"\u003e \u003ch2\u003e4.1.2 Analysis of Experimental Results\u003c/h2\u003e \u003cp\u003eThe experimental results clearly demonstrate that the incorporation of bamboo fibers has a significant impact on the cohesion and internal friction angle of soil, with these effects manifesting not only in the enhancement of macroscopic mechanical properties but also in providing deeper insights into the micro-level interaction mechanisms between bamboo fibers and soil structure.\u003c/p\u003e \u003cp\u003eCohesion, as the internal force that resists tensile or shear failure in soil, is primarily provided by the interactions between soil particles and cementing materials. The introduction of bamboo fibers reconstructs the soil structure at the micro-level, thereby influencing the exertion of these forces. Bamboo fibers, with their natural characteristics of high strength and high modulus, play the role of reinforcing bars in loose soil, enabling physical connections within the soil. At lower fiber contents, they primarily function as connectors in localized regions; as the content increases, they form a network structure within the soil, extending the physical connections to the entire space and thus enhancing cohesion. However, when the fiber content exceeds a certain limit, due to the finite number of binding particles in the soil, the bonding effect between the fibers and the soil no longer increases but instead exhibits a slight weakening trend.\u003c/p\u003e \u003cp\u003eThe internal friction angle serves as a critical parameter reflecting the frictional characteristics between soil particles. The elongated structure of bamboo fibers forms a \"network\" or \"skeleton\" within the soil, enhancing the overall stability of the soil and increasing the sliding resistance between particles. When the soil is subjected to shear forces, the fiber network can absorb and disperse the shear forces, thereby improving the shear strength and internal friction angle of the soil.\u003c/p\u003e \u003cp\u003eIn summary, the addition of bamboo fibers alters the structural characteristics of loose materials and the interaction mechanisms between particles and fibers at the micro-level. Within a certain range of fiber content, it enhances the cohesion and internal friction angle of the soil. However, beyond this range, a slight weakening trend is observed.\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv id=\"Sec12\" class=\"Section2\"\u003e \u003ch2\u003e4.2 Results and Analysis about Clay Content\u003c/h2\u003e \u003cdiv id=\"Sec13\" class=\"Section3\"\u003e \u003ch2\u003e4.2.1 Experimental Results\u003c/h2\u003e \u003cp\u003eIn the direct shear tests conducted to investigate the impact of varying clay content on the mixture's strength, the calibration coefficient of the force-measuring instrument, as well as the test area utilized in the computation of shear stress, were maintained as constants throughout the experimental procedure. The results obtained through these computations are depicted in Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003e.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eFigure \u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003e meticulously depicts the shear stress values of samples containing varying clay percentages, specifically ranging from BFS-8 to BFS-12, under diverse vertical pressure conditions. Each sample's data points are distinctly represented through unique colors and symbols, thereby enabling a clear visualization of the shear stress magnitudes associated with different clay contents under specific pressures. Despite the presence of slight data dispersion, discernible trends emerge from these observations.\u003c/p\u003e \u003cp\u003eTo augment the precision and credibility of the experimental findings and to address the inherent variability in the data points, a rigorous linear fitting approach was adopted to analyze the discrete data. Notably, all the fitting curves adhere to a first-degree linear function. The outcomes of this analysis are concisely presented in Fig.\u0026nbsp;\u003cspan refid=\"Fig7\" class=\"InternalRef\"\u003e7\u003c/span\u003e.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eTo conduct a deeper analysis of the impact of clay content on the mechanical characteristics of the mixture, and drawing upon the linear fitting results obtained from Groups BFS-8 to BFS-12, a linear plot is employed to elucidate the relationship between soil strength indices\u0026mdash;specifically cohesion and internal friction angle\u0026mdash;and the varying clay content. This comprehensive representation is vividly depicted in Fig.\u0026nbsp;\u003cspan refid=\"Fig8\" class=\"InternalRef\"\u003e8\u003c/span\u003e.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eThe experimental data and the corresponding result plots clearly indicate that as the clay content within the mixture undergoes an increase, both cohesion and internal friction angle display discernible patterns of variation. Specifically, as the clay content rises from 6\u0026ndash;16%, there is a gradual increase observed in both the cohesion and internal friction angle of the mixture. However, it is noteworthy that the rates of growth for both these parameters gradually diminish during this period. At a clay content of precisely 16%, the cohesion of the mixture attains its maximum value. Conversely, when the clay content surpasses 16% and continues to increase, both the cohesion and internal friction angle of the mixture exhibit a gradual decline.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec14\" class=\"Section3\"\u003e \u003ch2\u003e4.2.2 Analysis of Experimental Results\u003c/h2\u003e \u003cp\u003eBased on the aforementioned experimental findings, we can deduce the following patterns concerning the influence of clay content on the shear strength of the mixture:\u003c/p\u003e \u003cp\u003eAt relatively low clay contents, an increase in clay content leads to a gradual enhancement in the shear strength of the mixture. This enhancement stems from the ability of an appropriate quantity of clay particles to fill the interstitial spaces between bamboo fibers, soil particles, and among soil particles themselves. This filling action augments the bonding force between bamboo fibers and soil, as well as among soil particles, thereby bolstering the cohesive force and friction force of the mixture.\u003c/p\u003e \u003cp\u003eWhen the clay content attains a specific critical threshold, the shear strength of the mixture achieves its peak. At this juncture, the interplay between loose particles and bamboo fibers attains an optimal state, fostering the formation of a relatively stable structural system.\u003c/p\u003e \u003cp\u003eBeyond this critical clay content, the shear strength of the mixture commences a decline. This decrement arises due to the viscosity increase induced by an excessive amount of clay particles, which diminishes the friction force and bite force between particles. Furthermore, an abundance of clay particles may result in the formation of excessive cementing materials, rendering the mixture more prone to damage during shear processes.\u003c/p\u003e \u003cp\u003eIn light of the aforementioned experimental results, the pattern of strength variation under the influence of clay content can be categorized into three distinct stages: the joint reinforcement stage, the optimal strengthening stage, and the soil weakening stage. The joint reinforcement stage pertains to the process wherein the bonding force between fibers and soil, as well as among soil particles, undergoes concurrent augmentation. The optimal strengthening stage signifies the phase at which the mixture attains its utmost strength at the critical clay content. Conversely, the soil weakening stage denotes the process wherein the bonding force between fibers and soil ceases to increase, while the bonding force among soil particles progressively weakens.\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e"},{"header":"5 Microscopic Morphology Analysis","content":"\u003cp\u003eTo comprehensively analyze the characteristics of soil particle distribution, pore structure, bamboo fiber composition, texture, and other pertinent features within the mixture, and to elucidate the macroscopic mechanical behavior, Scanning Electron Microscopy (SEM), specifically a Desktop Scanning Electron Microscope manufactured by Phenom World (model: Phenom ProX, origin: Netherlands), was utilized to examine the microscopic morphology of sheared specimens. Figure 9 showcases the SEM images of the sheared mixture, offering a detailed visualization of its structural features.\u003c/p\u003e\n\u003cp\u003eUnder a magnification of 400x in Scanning Electron Microscope (SEM) images (a), bamboo fiber bundles are composed of multiple single fibers, exhibiting a distinct multi-filament morphology. The single fibers are observed to branch and intertwine among themselves. The diameter range of these single fibers, as indicated in the images, spans from 6um to 26um, highlighting their relatively minute size.\u003c/p\u003e\n\u003cp\u003eAt a magnification of 2500x (b), the soil appears as a collection of particles of varying shapes and sizes, which are cohesively bound together through physical and chemical interactions, forming a porous and rugged surface structure. Within a proximity of approximately 50um around the fibers, the soil particles are notably smaller, ranging in size from 4-42um, which is less than 0.075mm. This suggests that the vicinity of the fibers is predominantly populated by smaller micro-clay particles.\u003c/p\u003e\n\u003cp\u003eSEM images (c) captured at a magnification of 4500x reveal that following the shear test, the fibers and soil particles have undergone displacement, resulting in pores approximately 13um in size and inter-fiber distances of about 9um. These dimensions fall within the range of clay particles, indicating that the pores are primarily a result of the displacement of clay particles or their relative displacement to the fibers. In these SEM images, irregularly shaped and sized soil particle residues can be clearly seen adhering to the surface of the bamboo fibers. This indicates that during the pullout process, there was significant interaction between the soil particles and the bamboo fibers, causing some soil particles to be stripped and attached to the fibers. Additionally, minute scratches and wear marks are evident on the surface of the bamboo fibers, potentially due to friction and scraping of soil particles against the fiber surface during pullout. The presence of wear marks suggests that the bamboo fibers underwent a degree of plastic deformation and wear during the pullout process, further corroborating the strong bonding between bamboo fibers and soil.\u003c/p\u003e\n\u003cp\u003eAt a magnification of 12000x (d), the fiber surface exhibits a concave-convex morphology, providing favorable conditions for the embedding of clay binders. The clay particle diameter on the fiber surface ranges approximately from 2-6um, with even finer particle sizes observed. In the SEM images, the bonding interface between bamboo fibers and soil is also discernible. At this interface, soil particles can be seen tightly enveloping the bamboo fibers, forming a structure akin to \u0026quot;anchoring,\u0026quot; which enhances the physical connection between bamboo fibers and soil. Furthermore, minute protrusions and depressions formed by soil particles on the surface of bamboo fibers are visible, increasing the contact area and friction force between them.\u003c/p\u003e\n\u003cp\u003eIn summary, SEM images demonstrate that the area surrounding the fibers is predominantly filled with micro-clay particles with diameters less than 0.075mm. Moreover, as one approaches the fiber surface, the clay particle diameters decrease. Therefore, the connection between fibers and soil is primarily facilitated by micro-clay particles. Based on this characteristic, a structural model of the mixture and its failure mechanism was established, as depicted in Fig. \u003cspan class=\"InternalRef\"\u003e10\u003c/span\u003e.\u003c/p\u003e\n\u003cp\u003eThe composite mixture structure model elucidates that bamboo fibers and granular materials are primarily interconnected via micro-clay particles, with a predominant distribution of these particles observed on the bamboo fiber surface. The proximity to bamboo fibers correlates positively with the abundance of micro-clay particles.\u003c/p\u003e\n\u003cp\u003eThe direct shear test results, conducted across varying clay contents, effectively corroborate this model. During the reinforcement phase of the composite, an augmentation in clay content significantly enhances the adhesion between bamboo fibers and soil particles, as well as the cohesion among larger soil aggregates. At the optimal reinforcement stage, where the quantity of bamboo fibers and larger soil particles remains constant, the clay content achieves an optimal balance with these components, thereby maximizing the composite mixture\u0026apos;s strength. Conversely, in the soil weakening phase, as the clay content continues to rise, the maximum adhesion between bamboo fibers and soil is attained, with no further augmentation possible. However, an increase in clay particles among larger soil aggregates diminishes their supportive role and reduces the inter-particle friction, consequently weakening the overall composite strength.\u003c/p\u003e\n\u003cp\u003eIn summation, the distribution of micro-clay particles exerts a notable influence on the shear strength of the composite mixture. A moderate quantity of micro-clay particles can augment the shear strength, whereas an excessive amount, post-peak, will attenuate it.\u003c/p\u003e"},{"header":"6 Conclusions","content":"\u003cp\u003eThe present study aims to explore the mechanical properties of bamboo fiber-reinforced loose soil mixtures, providing scientific support for the reinforcement of loose soil slopes. Through direct shear tests and microscopic analysis, we conducted an in-depth investigation into the effects of bamboo fiber content and clay content on the shear strength of the mixtures.\u003c/p\u003e \u003cp\u003eThe research findings reveal that the incorporation of bamboo fibers significantly enhances the cohesion and internal friction angle of loose soil. As the bamboo fiber content increases, the shear strength of the mixtures exhibits an initial sharp increase followed by a slight decrease, with the most pronounced enhancement observed at bamboo fiber contents ranging from 0.5\u0026ndash;2%. Additionally, clay content exerts a significant influence on the strength of the mixtures; an appropriate amount of clay particles notably augments the shear strength, whereas an excess leads to a decline in strength. The variation in strength can be categorized into three stages: co-strengthening, optimal reinforcement, and soil weakening.\u003c/p\u003e \u003cp\u003eMicroscopic image analysis confirms that the fibers and loose soil are primarily connected through micro-clay particles, with a dense distribution of micro-clay particles on the surface of the bamboo fibers, and an increasing number of these particles as their proximity to the fibers decreases. Based on this observation, we established a structural model for the mixtures and their failure modes, which effectively explains the variation in mixture strength under different clay contents.\u003c/p\u003e \u003cp\u003eThe innovative aspects of this study lie in: systematically investigating the effects of bamboo fiber content and clay content on the mechanical properties of the mixtures, thereby filling a research gap; combining macro-mechanical tests with microscopic analysis to uncover the microscopic mechanisms underlying the reinforcement of loose soil by bamboo fibers; establishing a structural model; and proposing three stages of mixture strength variation.\u003c/p\u003e"},{"header":"Declarations","content":"\u003ch2\u003eData Availability\u003c/h2\u003e\n\u003cp\u003eThe datasets generated during and/or analysed during the current study are of significant importance for validating the research findings and enabling future research endeavors in the relevant field. In accordance with the principles of open science and data sharing, the authors are committed to ensuring that these datasets are accessible to the research community. Therefore, the datasets generated during and/or analysed during the current study are available from the corresponding author on reasonable request. Researchers interested in obtaining these datasets should contact the corresponding author, who will provide further instructions and conditions for data access, ensuring compliance with any relevant data protection and privacy regulations. The authors encourage responsible use and citation of the data in any subsequent research publications.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eIsrar M K ,Shuhong W ,Pengyu W , et al. Soil slope analysis to develop useful correlations in saturated and unsaturated conditions. \u003cem\u003eJ\u003c/em\u003e. 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Experimental Investigation on Shear Behavior and Mechanical Properties of Fine Sand Reinforced with Sugarcane Bagasse Fibers. \u003cem\u003eJ\u003c/em\u003e. International Journal of Geosynthetics and Ground Engineering.11 (1),2-3(2024).\u003c/li\u003e\n\u003cli\u003eQihong Y ,Chaobo Z ,Shiming Y , et al. Root Distribution and Root Cohesion of Two Herbaceous Plants in the Loess Plateau of China. \u003cem\u003eJ\u003c/em\u003e. Sustainability. 14 (13), 8053-8053(2022).\u003c/li\u003e\n\u003cli\u003eRamkrishnan R ,Sruthy M ,Sharma A , et al. Effect of random inclusion of sisal fibres on strength behavior and slope stability of fine grained soils. \u003cem\u003eJ\u003c/em\u003e. Materials Today: Proceedings. 5 (11),25313-25322(2018).\u003c/li\u003e\n\u003cli\u003eSrijan ,Gupta K A . Sustainable material as a column filler in soft clay bed reinforced with encased column: numerical analysis. \u003cem\u003eJ\u003c/em\u003e. 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Bioengineered. 12 (1), 7529-7551(2021).\u003c/li\u003e\n\u003cli\u003eHaystead J . The optimization of microbial induced calcium carbonate precipitation in soil improvement using engineered bacteria. \u003cem\u003eJ\u003c/em\u003e. Access Microbiology.1 (1A),(2019).\u003c/li\u003e\n\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":"[email protected]","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":"bamboo fiber, slope, loose soil, reinforcement, properties","lastPublishedDoi":"10.21203/rs.3.rs-5951765/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-5951765/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eThe stability of the slope is of great significance to the safety of life and property. In order to solve the problem of single -slope pine loose reinforcement methods, and the limitation in chemistry and biological methods, and bamboo fiber is used to strengthen the loose soil. Through direct shearing tests and scanning electron microscopes, the mechanical characteristics and interaction mechanism of bamboo fiber and loose soil reinforcement are studied. The research results show that the fiber and loose soil is mainly connected through micro-particles. The closer to the fiber, the more the number of micro -grains; with the increasing of fiber content, the increase in the shear strength of the mixture is increased sharply after the shear strength increases first, and then slightly decreased; appropriate amount of micro -mucous particles can significantly enhance the shear strength of the mixture, and excessive micro -mucous particles can cause the intensity of the mixture to decrease. The results of the research can provide theoretical reference for engineering projects such as road slope, building slope, tail mining, and artificial pile of earth soil.\u003c/p\u003e","manuscriptTitle":"Study on the Mixing Properties of Bamboo Fiber and Loose Soil","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-02-14 12:45:18","doi":"10.21203/rs.3.rs-5951765/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","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":"27511310-6fbb-41ea-aff8-2f6bdb19ff9e","owner":[],"postedDate":"February 14th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[{"id":44312744,"name":"Physical sciences/Engineering/Civil engineering"},{"id":44312745,"name":"Physical sciences/Materials science"}],"tags":[],"updatedAt":"2025-03-03T05:54:47+00:00","versionOfRecord":[],"versionCreatedAt":"2025-02-14 12:45:18","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-5951765","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-5951765","identity":"rs-5951765","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}