摘要
引黄(河)入洛(阳)工程新近系围岩中有粉质黏土夹层或充填物,其力学强度随含水量变化很大,是导致施工围岩破坏的主要诱因之一。为深入分析含水率对围岩强度的影响,采用不固结不排水三轴试验,研究含水率对粉质黏土强度的影响。试验结果表明:试样破坏均为中部鼓肚膨胀综合破坏,体积膨胀起主要作用,其中径向膨胀变形过大是导致试样破坏的主要原因;含水率对主应力差影响很大,随着含水率增大,主应力差显著降低,其降低幅度随围压增大而加大;峰值强度受含水率的影响较大,随含水率的增大而明显降低,随含水率和围压增大,峰值强度降低幅度加大,达到较高含水率后峰值强度受围压的影响很小;相同围压下,峰值应力比随含水率的增大而呈线性递减,各拟合直线的斜率基本一致;相同含水率下,峰值应力比随围压的增大而减小;含水率对强度参数影响较大,随着含水率的增大,粉质黏土的黏聚力和内摩擦角均明显减小,黏聚力的对数值及内摩擦角与含水率呈负线性相关。
There is silty clay interlayer or its filler in Neogene surrounding rock in the project for transferring water from the Yellow River intoLuoyang, and its mechanical strength has great changes with the moisture content change, which is one of the main incentive causes for thefailure of constructing surround rock. In order to deeply analyze the effect of moisture content on rock, the triaxial unconsolidated undrainedtest was done to study the effect of moisture content on Neogene silty clay. The results show that the comprehensive destructing form ofsamples is middle bulging with inflation, mainly owing to volume expansion, and the main reason of sample failure results from large radialexpansion; water content has a great influence to the principal stress difference, which significantly decreased with water content beingincreased, and its decreased range is increasing with the increasing of confined pressure; the peak strength of samples is greatly influenced bywater content, and peak strength obviously decreases with increasing water content, and the lowered range is faster increasing with theincreasing of moisture content and confined pressure, but effect of the confined pressure on the peak strength is less after reaching to a certainwater content; under the same confined pressure, the peak stress ratio linearly decreases with the increasing water content, and when fittedstraight line, the slope of each line is basically the same, and under the same moisture content, the peak stress ratio decreases with theincreasing confined pressure. The moisture content has strong effect on strength parameters of samples, and the value of c and decreasessignificantly with increasing moisture content, and the interrelation between logarithm of c and moisture content is negative linear, which is asto the interrelation between φ and water content.
出处
《人民黄河》
CAS
北大核心
2016年第4期125-128,共4页
Yellow River
基金
2015年度河南省基础与前沿技术研究项目(152300410216)
关键词
含水率
强度
围压
三轴试验
新近系粉质黏土
moisture content
strength
confined pressure
triaxial unconsolidated undrained test
Neogene silty clay
作者简介
薛振声（1963-）,男,河南偃师人,高级工程师,主要从事水利工程建设管理工作.E-mail：1036425851＠qq.com
