岩土力学2025，Vol.46Issue(5)：1620-1631,12.DOI:10.16285/j.rsm.2024.1109
基于内聚力单元的土石混合体细观数值方法
A mesoscopic numerical method for simulating soil-rock mixture based on cohesive zone element
摘要
Abstract
The soil-rock mixture is a heterogeneous material consisting of high-strength rocks and a low-strength soil matrix,with complex interactions among its mesoscopic components under loading.Considering the mesoscopic structural characteristics,the interface between soil and rock,as well as the interior of the soil matrix,are identified as the material's weak points.Using the cohesive model,the initiation,expansion,and fracture of cracks at weak points are described,and a cohesive element insertion program is developed.Subsequently,using the results of direct shear tests,the material parameters for the cohesive elements in the soil matrix and at the soil-rock interface are determined.A mesoscopic numerical method for soil-rock mixtures based on the cohesive model is then established.Based on this,biaxial compression numerical tests on soil-rock mixtures with varying mesoscopic structures were conducted.The influence of different mesoscopic factors on mechanical properties was clarified by analyzing the failure state of cohesive elements.Results indicate that the maximum nominal stress in shear direction of cohesive elements can be determined by the peak shear stress of the load-displacement curve in direct shear tests.The maximum effective displacement is determined by one-fifth of the maximum shear displacement,and the tangential friction coefficient is calculated by the ratio of residual shear stress to normal stress.The numerical method based on cohesive elements can effectively describe the mechanical properties and deformation behavior of soil-rock mixtures,particularly for the strain softening behavior under low confining pressure.关键词
土石混合体/内聚力模型/细观数值方法/界面力学行为/应变软化Key words
soil-rock mixture/cohesive zone model/a mesoscopic numerical method/mechanical behavior of interface/strain softening分类
建筑与水利引用本文复制引用
张佩,杨承儒,侯世伟,杜修力..基于内聚力单元的土石混合体细观数值方法[J].岩土力学,2025,46(5):1620-1631,12.基金项目
国家自然科学基金项目(No.51908023,No.52025084) （No.51908023,No.52025084）
北京市自然科学基金项目(No.8232007) （No.8232007）
北京市教委科研项目——科技计划一般项目(No.KM202310016013) （No.KM202310016013）
北京建筑大学金字塔人才培养工程项目(No.JDYC20200312).This work was supported by the National Natural Science Foundation of China(51908023,52025084),the Natural Science Foundation of Beijing(8232007),the Science and Technology General Project of Beijing Municipal Education Commission(KM202310016013)and the Pyramid Talent Cultivation Project of Beijing University of Civil Engineering and Architecture(JDYC20200312). （No.JDYC20200312）
