基于力链的土体直剪试验颗粒流数值模拟研究  

Numerical Simulation of Direct Shear Test of Soil Based on Force Chain

作　　者：朱建 万加根 季圣星 孙军 周领 汤锦荣 许涛 ZHU Jian;WAN Jiagen;JI Shengxing;SUN Jun;ZHOU Ling;TANG Jinrong;XU Tao(Jiangxi Provincial Highway and Bridge Engineering Co.,Ltd.,Nanchang 330096,Jiangxi,China;School of Civil and Architecture Engineering,East China University of Technology,Nanchang 330013,Jiangxi,China)

机构地区：[1]江西省公路桥梁工程有限公司,江西南昌330096 [2]东华理工大学土木与建筑工程学院,江西南昌330013

出　　处：《水力发电》2025年第5期30-36,111,共8页Water Power

基　　金：国家自然科学基金资助项目(52264003)。

摘　　要：从细观力学角度研究岩土体的宏观力学行为是岩土工程领域的研究热点之一。选取原状黄土进行室内直剪试验,基于PFC 2D颗粒流方法构建土体直剪模型,分析直剪过程中土体的力链分布及接触力方向的变化,从细观层面研究土体直剪过程中的宏观力学行为。研究结果显示,室内直剪试验与数值模拟试验的结果具有良好一致性,验证了数值模拟试验的可靠性;在剪切应力达到峰值前,力链网络发生规律性变化,强力链逐渐由竖直方向向角平分线方向集中;当剪切应力达到峰值时,内部接触力方向与水平方向约呈40°夹角,随着剪切位移的进一步增加,部分强力链超出其承载极限发生断裂,转化为弱力链并在内部重新分布。Studying the macroscopic mechanical behavior of geotechnical materials from a mesomechanical perspective is a key focus in geotechnical engineering.This study conducts direct shear tests on undisturbed loess,and based on the PFC^(2D)particle flow method,establishes a direct shear model to analyze force chain distribution and changes in contact force direction during the shear process,for investigating the macroscopic mechanical behavior of soils during direct shear from a mesoscopic viewpoint.The results indicate a strong consistency between laboratory direct shear tests and numerical simulations,confirming the reliability of the simulations.Before the peak shear stress is reached,the force chain network undergoes systematic changes,with strong force chains gradually concentrating from the vertical direction toward the bisector of the shear angle.At peak shear stress,the contact force direction within the material forms an approximately 40°angle with the horizontal axis,and as the shear displacement increases further,some strong force chains exceed their load capacity and fracture,and then transition into weaker force chains that redistribute within the material.

关 键 词：黄土 直剪试验 颗粒流方法 力链 接触力方向Particle Flow 

分 类 号：TU411[建筑科学—岩土工程]