The lateral pressure coefficient at rest of expansive soils in landfill at various vertical stresses and moisture contents

作     者：ZHOU Zhen-hua KONG Ling-wei SUN Zhi-liang LI Tian-guo YAN Jun-biao ZHOU Zhen-hua;KONG Ling-wei;SUN Zhi-liang;LI Tian-guo;YAN Jun-biao

作者机构：State Key Laboratory of Geomechanics and Geotechnical EngineeringInstitute of Rock and Soil MechanicsChinese Academy of SciencesWuhan430071China University of Chinese Academy of SciencesBeijing100049China 

出 版 物：《Journal of Mountain Science》 (山地科学学报（英文）)

年 卷 期：2023年第20卷第4期

页      面：1102-1117页

核心收录：

学科分类：081401[工学-岩土工程] 08[工学] 0814[工学-土木工程] 

基　　金：supported by the National Key Research and Development Program of China(Grant No.2019YFC1509901) 

主　　题：Expansive soil k_(0)value Landfill Vertical stress Moisture content 

摘      要：When expansive soils in the original location are artificially transferred to landfill in different seasons,and subject to engineering activities afterwards,the corresponding deformation and stability of retaining structures become *** necessitates the determination of lateral pressure coefficient at rest(k_(0) value)for expansive soils in *** compaction,excavation of expansive soils,as well as construction of landfill in different seasons,series of stepwise loading and unloading consolidation tests at various moisture contents were carried out in this work to explore the evolution characteristics of k_(0) value and assess the dependence of k_(0) value on vertical stress and moisture ***,scanning electron microscope(SEM)was used to track the change in microstructural features with vertical *** results indicated that the k_(0) value of expansive soil shows a pronounced nonlinearity and is inextricably linked with vertical stress and moisture content,based on which a prediction formula to estimate the variation in k_(0) value with vertical stress during loading stage was proposed;there is a significant exponential increase in k_(0) value with overconsolidation ratio(OCR)during unloading stage,and OCR dominates the release of horizontal stress of expansive soil;SEM results revealed that with an increase in vertical stress,the anisotropy of expansive soil microstructure increases dramatically,causing a significant directional readjustment,which is macroscopically manifested as an initially rapid increase in k_(0) value;but when vertical stress increases to a critical value,the anisotropy of microstructure increases marginally,indicating a stable orientation occurring in the soil microstructure,which causes the k_(0) value to maintain a relatively stable value.