压实昔格达土料及其与既有填土界面剪切特性研究

Shear Properties of Both Xigeda Soil and Its Compaction with Existed-filling Interface

鉴于新增压实昔格达填土及其与既有填土界面抗剪强度直接影响高填方区域稳定性,通过改进直剪试验制样方式,设定2类因素4种应力水平共32组试样,并采用固结快剪探究压实昔格达土料与既有填土界面剪切特性。结果表明,在不同法向应力下含界面试样剪应力-位移变化曲线呈剪切硬化状态,干密度对其应力-位移曲线的影响分为应变软化与应变硬化两个阶段;与新增压实昔格达土体抗剪强度相比,相同干密度下含界面试样的粘聚力大幅降低,最大降幅为32.50%,内摩擦角微弱增大,最大增幅为7.78%;消弱昔格达填土界面效应的适宜干密度为1.285g/cm3,即为界面填土填筑干密度建议值。

Shear strength of Xigeda soil and its compaction with existed-filling interface has directly impact on the regional stability of high embankment.Through the improvement of direct shear test sample preparation,32 groups of samples were classified into 2 factors and 4 stress levels,and the consolidated quick shear test was used to inquiry the shear strength of Xigeda soil and its compaction.The results show that the shear stress-displacement curves of soil samples contained interface appear shear hardening state under different normal stresses;the impacts of dry density on the stress displacement curves are divided into two parts,the former is strain softening and the latter is strain hardening.Compared with shear strength of Xigeda soil in the same dry density,the cohesion of test samples within interface significantly are reduced,and the maximum reduction reaches 32.50%;internal friction angle slightly increases,and the maximum increase attains 7.78%.The suitable dry density to undermine the interface effect of Xigeda soil is 1.285 g/cm^3,which is the suggested value of dry density in interface filled of Xigeda soil.