Research on Shear Resistance of Rooted Soil under Freeze-Thaw Cycles Based on DEM
Shi Zhenming
Zhu Xin
Liu Maomao
He Guangyao
Xia Chengzhi
Abstract：To investigate the shear resistance performance and meso-damage mechanisms of herbaceous plant root-soil systems under freeze-thaw cycles,this study focused on wolfsbane root-soil composites.A representative three-dimensional root system model was constructed.The freeze-thaw damage process was characterized by simulating the expansion effect of water-ice particle phase transformation using the discrete element method(DEM).A three-dimensional direct shear numerical model for the root-soil composite was calibrated based on indoor experimental data.The study systematically investigated the influence of freeze-thaw cycle count,shear rate,and normal load on the shear strength,damage mechanisms,and synergistic shear-resistance mechanism of the root-soil composite.The research findings revealed that:(1)The incorporation of roots significantly enhances the shear strength of the soil,with the anchoring effect of vertical roots playing a primary role.Fibrous roots can further augment the three-dimensional reinforcement effect.(2)Loading rate exhibits a positive correlation with both normal load and peak shear strength.However,its impact on the intrinsic pattern of shear strength degradation caused by freeze-thaw damage is relatively minor.(3)Freeze-thaw damage primarily manifests as the deterioration of particle bonding within the specimen,induced by volumetric changes during phase transitions in the freeze-thaw process.This leads to a reduction in interfacial forces between roots and soil during shear,thereby diminishing the soil's shear strength.The results elucidate the interaction mechanism between plant root soil reinforcement and freeze-thaw cycles.They provide a reference basis for the eco-reinforcement design of slope engineering in cold regions,offering significant engineering guidance significance,notably under extreme freeze-thaw scenarios.
Keywords：discrete elementsroot-soil complexfreeze-thaw cycledirect shearengineering geology
Publication Date：2025-10-30
Online Publishing Date：2025-11-11(First online date of this platform, not the publication date of the document)
Pages：15( 3761-3775 )