Direct shear tests of coarse-grained fillings from high-speed railway subgrade in cold regions  

作　　者：Qing Zhi Wang Jian Kun Liu Jian Hong Fang An Hua Xu 

机构地区：[1]School of Civil Engineering, Beijing Jiaotong University [2]Qinghai Research Institute of Transportation

出　　处：《Research in Cold and Arid Regions》2017年第3期236-242,共7页寒旱区科学（英文版）

基　　金：supported by the National Natural Science Foundation of China (No. 51378057)

摘　　要：In order to study the shear behavior of coarse-grained fillings taken from the subgrade bottom layer of a cold region high-speed railway,large scale direct shear tests were conducted with different normal pressures,water contents and temperatures.The results indicate that the relationship between shear displacement and shear stress changed from strain-softening at lower normal pressures to strain-hardening at higher normal pressures,in both unfrozen and frozen states.This phenomenon was mainly due to the shear dilatation deformation effect.The shear displacement-shear stress curves show similar stages.Besides,the shear stress rapidly increased and there was not an increment in the shear displacement during the initial stage of the shear process in the frozen state.In both the unfrozen or frozen states at the same water contents,the shear strength increased with increasing normal pressure.In order to study the shear behavior of coarse-ined fillings taken from the sub de bottom layer of a cold region high-speed railway, large scale direct shear tests were conducted with different normal pressures, water contents and temperatures. The results indicate that the relationship between shear displacement and shear stress changed from strain-softening at lower normal pressures to strain-hardening at higher normal pressures, in both unfrozen and frozen states. This phenomenon was mainly due to the shear dilatation deformation effect. The shear displacement-shear stress curves show similar stages. Besides, the shear stress rapidly increased and there was not an increment in the shear displacement during the initial stage of the shear process in the frozen state. In both the unfrozen or frozen states at the same water contents, the shear strength increased with increasing normal pressure.

关 键 词：COARSE-GRAINED fillings large SCALE direct test SHEAR displacement-shear stress CURVE SHEAR STRENGTH 

分 类 号：U213.1[交通运输工程—道路与铁道工程]