Water retention behavior and shear strength of artificially cemented granite residual soil subjected to free drying  

作　　者：Xinxin Dong Xiaohua Bao Hongzhi Cui Changjie Xu Xiangsheng Chen 

机构地区：[1]MOE Key Laboratory of Coastal Urban Resilient Infrastructures(Shenzhen University),College of Civil and Transportation Engineering,Shenzhen University,Shenzhen,518060,China [2]State Key Laboratory of Intelligent Geotechnics and Tunnelling,Shenzhen University,Shenzhen,518060,China [3]School of Civil Engineering and Architecture,East China Jiaotong University,Nanchang,330013,China

出　　处：《Journal of Rock Mechanics and Geotechnical Engineering》2024年第11期4697-4710,共14页岩石力学与岩土工程学报（英文）

基　　金：supported by the National Natural Science Foundation of China (Grant Nos.52379104,42202298);Joint fund of National Natural Science Foundation of China-Railway Corporation for basic research of high-speed railway (Grant No.U1934208).

摘　　要：Artificially cemented soils have been widely used as filling materials in highway and railway construction.The shear strength evolution of filling materials upon moist variation can determine the stability of subgrade and embankments.This study conducted water retention tests,MIP tests,and multi-stage triaxial shear tests on cement-treated granite residual soil(GRS)to determine its water retention curve(WRC)upon free drying,pore structure,and peak shear strength qf,respectively.The water retention behavior and shear strength evolution upon free drying were modeled based on the dual-porosity structure of cement-treated GRS and the effective stress principle,respectively.Results show that the drying-WRC is bimodal and higher cement dosage yields a more severe decrease in the water retention capacity within a specific suction range.For a given confining pressure,the peak shear strength qf increased with increasing cement dosage or suction value s.The peak shear strength qf also solely depends on the suction value in the peak stress state.In addition,the cement-treated GRS has a bimodal pore size distribution curve,and its macro-and micro-void ratios remain almost unchanged after free drying.The bimodal drying-WRC of the cement-treated GRS can be modeled by differentiating the water retention mechanisms in macro-and micro-pores.Moreover,using the macro-pore degree of saturation as the effective stress parameterχ=S_(rM),the q_(f)–p′_(f)relationship(where p′_(f)is the effective mean pressure at failure)under various suction and stress conditions can be unified,and the q_(f)–s relationships at various net confining pressuresσ_(3),net can be well reproduced.These findings can help design subgrade and embankments constructed by artificially cemented GRS and assess their safe operation upon climate change.

关 键 词：Granite residual soil Cement treatment DUAL-POROSITY Water retention behavior Unsaturated shear strength 

分 类 号：TU45[建筑科学—岩土工程]