含水率对残坡积土强度特性的影响  

Influence of Water Content on Residual Soil Strength Property

作　　者：王闯[1] 董金玉[1] 王明龙 李梦姿 张培培[3] 

机构地区：[1]华北水利水电大学,河南郑州450045 [2]深圳市地质环境监测中心,广东深圳518034 [3]黄河勘测规划设计有限公司,河南郑州450003

出　　处：《华北水利水电大学学报（自然科学版）》2016年第5期88-92,共5页Journal of North China University of Water Resources and Electric Power：Natural Science Edition

基　　金：国家自然科学基金青年基金资助项目(41102203);河南省科技创新人才计划;水利部公益性行业科研专项经费项目(201301034);盾构及掘进技术国家重点实验室开放课题(2013-07);华北水利水电大学青年科技创新人才支持计划项目

摘　　要：水对边坡土体的变形和强度有着重要的影响。通过对三峡库区某边坡残坡积土进行不同含水率下的直剪试验,研究含水率对其剪应力-位移以及强度的影响规律。结果表明:残坡积土在低含水率下的剪应力-剪切位移关系呈应变软化,在高含水率下呈应变硬化,且含水率较低时竖向压力对残坡积土的应力-应变曲线亦有影响,随着竖向压力增加,剪切软化现象逐渐减小;土体抗剪强度随着含水率的增大而呈非线性减小,减小的速率表现出先大后小的特征,土体塑限为其抗剪强度减小快慢的分界点;土体黏聚力随着含水率的增大呈二次多项式形式减小,土体内摩擦角整体上随含水率的增大而变小,但变化规律不明显。Water has an important influence on deformation and strength of the soil slope. In this paper, direct shear tests were performed to study the influence of water content on shear strength of soil taken from the slope of the Three Gorges Reservoir area. The test results show that the shear stressshear displacement relationship under the condition of low water content was strain softening and strain hardening under the condition of high water content; and the vertical pressure under the condition of the low water content also has influence on the stress-strain curve of the residual, and the shear softening phenomenon gradually decreases with the increase of the vertical pressure. The soil shear strength decreases nonlinearly with the increase of water content and the reduced rate is firstly big, and then become small, and the plastic limit of the soil is the turning point. The soil cohesion decreases with the increase of water content as a quadratic polynomial, and the soil internal friction angle on the whole decreases with the increase of water content, but the variation is not obvious.

关 键 词：残坡积土 含水率 剪应力-剪切位移关系 抗剪强度 黏聚力 内摩擦角 

分 类 号：TV16[水利工程] TU411.7[建筑科学—岩土工程]