土石坝工程中填土料剪切力学试验特性研究

Research on shear mechanics test characteristics of filling materials in earth-rock dam engineering

为研究武烈河防洪干堤土石坝二次加高堆筑料黏土体的剪切力学特性,设计开展了土体黏土成分含量、环境氯盐溶液参量两种影响性试验。黏土成分含量对黏土体剪切应力影响在含量60%前、后区间内分别为增大、递减特征,在无化学溶液环境参量组中前、后区间的增幅、降幅分别为24.1%、12.3%;当环境参量溶液浓度增大,黏土成分含量对土体剪切应力影响具有促进效应。环境参量溶液浓度与土体抗剪强度为负相关,在黏土成分含量50%与80%试验组中,溶液浓度每增大2 g/L,抗剪强度平均降幅分别为15%、8.3%。黏土成分含量超过60%后,土体峰值应力后期呈应变硬化型,而环境溶液浓度对后期应力位移变化影响较弱;黏土成分含量60%试样的弹性模量为最高,溶液浓度增长2 g/L,可导致土体弹性模量降幅22.8%。论文可为研究水利工程中填筑料土体的剪切力学试验特性提供一定参考。

In order to study the shear mechanical properties of the clay body of the secondary heightening of the earth-rock dam of the Wulie River flood control dry embankment,two influence tests were designed and carried out for the content of the clay content of the soil body and the parameters of the environmental chloride salt solution.The influence of clay component content on the shear stress of the clay body is characterized by increasing and decreasing respectively before and after the content of 60%;When the concentration of the environmental parameter solution increases,the clay content has a promoting effect on the influence of the soil shear stress.The environmental parameter solution concentration is negatively correlated with the soil shear strength.In the experimental groups with clay content of 50% and 80%,the shear strength decreases by 15% and 8.3% on average when the solution concentration increases by 2 g/L.When the clay content exceeds 60%,the peak stress of the soil shows a strain hardening type in the later stage,and the environmental solution concentration has a weak effect on the later stress and displacement change;the elastic modulus of the sample with a clay content of 60% is the highest,and the solution concentration increases by 2 g/L,which can lead to a 22.8% decrease in soil elastic modulus.This paper can provide some reference for studying the shear mechanical test characteristics of soil filling materials in hydraulic engineering.