三轴压缩条件下裂隙性黄土应力-应变特性及变形破坏机制  

Stress-strain Features and Deformation Failure Mechanisms of Fissured Loess Under Triaxial Compression

作　　者：卢全中[1,2] 陈树峰[1,2] 彭建兵[1,2] 孟振江[1,2] 胡鹏[1,2] 

机构地区：[1]长安大学地质工程系,陕西西安710054 [2]长安大学西部矿产资源与地质工程教育部重点实验室,陕西西安710054

出　　处：《中国公路学报》2015年第1期8-16,共9页China Journal of Highway and Transport

基　　金：国家重点基础研究发展计划("九七三"计划)项目(2014CB744702);国家自然科学基金重点项目(41130753);国家自然科学基金项目(41272284);国土资源大调查项目(12120113004900);陕西省科技统筹创新工程计划项目(2011KTZB03-02-02);国家留学基金项目(201206565031)

摘　　要：为了了解裂隙性黄土的应力-应变特性及变形破坏机制,通过三轴压缩试验,总结了不同含水量、不同裂隙角度的裂隙性黄土样在不同围压下的应力-应变曲线类型,分析了其变形破坏机制;采用元件组合模型,模拟了裂隙性黄土的应力-应变关系。结果表明:裂隙性黄土的应力-应变曲线有理想弹脆性极强软化型、弹塑脆性强软化型、折线软化型、曲线软化型、复合软化型、弹理想塑性型、理想弹塑性型和弹塑性硬化型共8种类型,其变形破坏机制表现为挤压-滑动、挤压-滑移(蠕滑)、挤压-横向拉裂、弯曲-滑移(或塑流)、弯曲-纵向拉裂和弯曲-旋转或扭转6种;裂隙性黄土的变形破坏方式受土样的含水量、母土性质、裂隙角度和试验围压的控制和影响,采用胶结杆与弹簧、滑片等元件组成的模型可用来模拟土样发生轴向变形时的突发性和渐进式破坏。In order to find out stress-strain feat fissured loess, shapes of stress-strain curves of f contents and different angle values of fissure under and their deformation failure mechanisms were ures lssur and deformation failure mechanisms of ed loess samples with different moisture different confining pressures were summarized analyzed based on the results of triaxial compression tests, and stress-strain relations of the samples element model. The results show that there are 8 types of str strong softening with brittleness, polygonal plasticity, deformation were simulated with combined ess-strain curves, including very perfect elasticity-brittleness, strong softenin SO perfect elastic ftening, curvilin plasticity and failure mechanisms including ear softening, composite g with ela softening, elastic-plastic hardening, and there compression-slide, compression-glide sticity plasticity- elastic-perfectly are 6 kinds of （or creeping） ,compression-transverse cracking, bending-creeping, bending- longitudinal cracking and bending- rotation or torsion. These deformation failure characteristics and modes of fissured loess samples are affected by such factors as moisture content, angle value and parent loess properties in samples and confining pressures of tests. Dropping or progressive brittle failure in axial deformation can be simulated by element model combined with springs, gliding slabs and cementation bars.

关 键 词：道路工程 裂隙性黄土 三轴压缩试验 应力-应变特性 元件组合模型 变形破坏机制 

分 类 号：U419.4[交通运输工程—道路与铁道工程]