摘要
实际工程中,含水率对土的抗剪强度影响较大,探究含水率对非饱和黄土抗剪强度的作用对于工程的安全十分重要。对不同含水率、不同干密度的非饱和黄土试样进行直剪试验以研究非饱和黄土的抗剪强度,并采用露点水势仪与滤纸法相结合的方法测定非饱和黄土的土–水特征曲线。结合对非饱和黄土的微观结构的研究,分析含水率对微观结构的影响。试验结果表明:随着含水率的增加,土的抗剪强度降低,含水率的增加降低了土的黏聚力,也降低了内摩擦角,但对内摩擦角的影响较小。在此基础上,根据试验结果分析含水率与非饱和土抗剪强度指标之间存在的函数关系,再通过分析土–水特征曲线中含水率与基质吸力的函数关系,建立了以基质吸力为变量的抗剪强度公式。
Determining the relationship between moisture content and shear strength is of guiding significance for engineering.The direct shear tests are carried out on the unsaturated loess samples with different moisture content and dry densities to study the shear strength of unsaturated loess,and the soil-water characteristic curve of unsaturated soil is determined by the method combining the dew point water potential meter and the filter paper method.Based on the researches on the microstructure of unsaturated soils,the influences of moisture content on the microstructure are analyzed.The test results show that as the moisture content increases,the shear strength of the soils decreases,and the increase in the moisture content reduces the cohesion of the soils and the internal friction angle,but has little effect on the internal friction angle.On this basis,the functional relationship between the moisture content and the shear strength index of unsaturated soils is analyzed,and then by analyzing the functional relationship between the moisture content in the soil-water characteristic curve and the matrix suction,a formula for the shear strength is proposed by regarding the matrix suction as the variable.
作者
蔡国庆
张策
黄哲文
李俊霖
侯剑龙
CAI Guo-qing;ZHANG Ce;HUANG Zhe-wen;LI Jun-lin;HOU Jian-long(Key Laboratory of Urban Underground Engineering of Ministry of Education,Beijing Jiaotong University,Beijing 100044,China;School of Civil Engineering,Beijing Jiaotong University,Beijing 100044,China)
出处
《岩土工程学报》
EI
CAS
CSCD
北大核心
2020年第S02期32-36,共5页
Chinese Journal of Geotechnical Engineering
基金
中央高校基本科研业务费专项资金项目(2020JBM048)
国家自然科学基金项目(52078031,U2034204,52042201)
北京市自然科学基金面上项目(8202038)
关键词
直剪试验
抗剪强度
含水率
非饱和土
基质吸力
direct shear test
shear strength
moisture content
unsaturated soil
matrix suction