颗粒形状对循环荷载作用下砂砾石土力学特性的影响  

Effect of Particle Shape on Mechanical Properties of Sandy Gravel Soil under Cyclic Loading

作　　者：彭军 PENG Jun(Fujian Hydrogeological Engineering Geological Survey and Research Institute,Zhangzhou 363000,China)

机构地区：[1]福建省水文地质工程地质勘察研究院,漳州363000

出　　处：《粉煤灰综合利用》2025年第1期74-81,共8页Fly Ash Comprehensive Utilization

摘　　要：颗粒形状是砂砾石土力学性质主要影响因素之一。为揭示颗粒形状对循环荷载作用下砂砾石土力学性质影响规律和机理,采用颗粒流离散元方法对砂砾石土的循环剪切试验进行仿真。通过对比试验,将颗粒形状影响因子单独分离,获取颗粒形状对砂砾石土宏细观力学响应的影响。结果表明:在给定的循环荷载作用下,颗粒形状对平均动模量和临界摩擦角基本无影响,颗粒形状的不规则性会导致峰值摩擦角降低;颗粒形状对剪切模量基本无影响,但不规则的颗粒形状会使最大剪胀角有一定程度的降低;不规则的颗粒形状会使循环荷载作用下e-p临界状态线的斜率变大、截距变小;在细观层面,均一化后的接触密度不受颗粒形状的影响,均一化的接触力分布不受颗粒形状的影响,接触力异向性不受颗粒形状的影响。研究结果可对铁路路堤以及土石坝的填料设计有一定的指导意义。Particle shape is one of the important factors affecting the mechanical properties of sand and gravel soils.In order to reveal the influence law and mechanism of particle shape on the mechanical properties of sand-gravel soil under cyclic loading,the particle flow discrete element method was used to simulate the cyclic shear test of sand-gravel soil.Then,by setting up refined comparative experiments,the influencing factors of particle shape are separated separately,and the effect of particle shape on the macro-mechanical response of sand-gravel soil is obtained.The results show that under a given cyclic load,the particle shape has little effect on the mean dynamic modulus,the peak friction angle is reduced due to the irregularity of the particle shape,and the critical friction angle is hardly affected by the particle shape;It has no effect on the shear modulus under cyclic loading,but the irregular particle shape will reduce the maximum dilation angle to a certain extent;the irregular particle shape will change the slope of the e-p critical state line under cyclic loading.Larger,smaller intercept;under the action of cyclic load,at the mesoscopic level,the contact density after homogenization is not affected by the particle shape,the uniform contact force distribution is not affected by the particle shape,and the contact force anisotropy is not affected.affected by particle shape.The research results help to construct a more accurate constitutive relation of sand-gravel soil.

关 键 词：颗粒形状 砂砾石土 循环荷载 离散元 剪胀性 

分 类 号：TU43[建筑科学—岩土工程]