摘要
为研究黄土在主应力轴循环旋转条件下的变形特性,采用空心圆柱扭剪仪(HCA)开展了2种不同应力路径下的扭剪试验。第1种应力路径为保持主应力轴方向不变,改变偏应力大小,研究黄土在不同主应力轴方向角α和不同中主应力系数b下的变形特性;第2种应力路径为保持偏应力大小不变,改变主应力轴方向,研究主应力轴循环旋转周期对黄土性状的影响。试验结果表明:土样剪切强度与中主应力系数b、主应力轴方向角α相关,当b相同,α=30°时土样剪切强度最大,α=60°时土样剪切强度略大于α=45°时;α相同时,剪切强度>b=1时的剪切强度>b=0.5时的剪切强度;纯主应力轴旋转会使土体产生塑形应变,并且随着旋转周期的增加,土体产生的塑形应变将不断累积。
To study the deformation characteristics of Loess under the cyclic rotation of the principal stress axes,two different torsional shear tests are performed under different stress paths using the hollow cylindrical torsional shear apparatus(HCA).The first stress path keeps the direction of the principal stress axes unchanged,but the size of deviator stress applied to the soil is changed.The first test is to study the deformation characteristics of the soil under the condition of different principal stress direction angleαand different intermediate principal stress parameter b values.The second stress path changes the direction of the principal stress axes,but the size of the deviator stress applied to the soil is unchanged.The second test is to study the effects of the cyclic rotation periods of the principal stress axes on the characteristics of the soil.The experimental results show that the deformation characteristics of Loess have a certainrelationship with the principal stress direction angle and intermediate principal stress parameter.When bis constant,the shear strength is the largest whenα=30°and whenα=60°,the shear strength is slightly larger than that whenα=45°.Whenαis constant,the shear strength when b=0 is larger than that when b=1,which larger than that when b=0.5.Pure principal stress axes rotation causes the soil to produce plastic strain,which will accumulate with the increase in the rotation cycles.
作者
翁效林
赵彦虎
张玉伟
李豪
刘保健
WENG Xiao-lin;ZHAO Yan-hu;ZHANG Yu-wei;LI Hao;LIU Bao-jian(Key Laboratory for Special Area Highway Engineering of Ministry of Education, Chang'an University, Xi'an 710064, Shaanxi, China;State Key Laboratory of Frozen Soil Engineering, Northwest Institute of Eeo-environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, Gansu, China;University of Chinese Academy of Sciences, Beijing 100049, China;School of Civil Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, Shaanxi, China)
出处
《中国公路学报》
EI
CAS
CSCD
北大核心
2018年第5期9-16,共8页
China Journal of Highway and Transport
基金
国家自然科学基金项目(51378004)
关键词
道路工程
黄土
主应力轴旋转
主应力轴方向角
中主应力系数
变形
road engineering
loess
principal stress axes rotation
principal stress direction an-gle
intermediate principal stress parameter
deformation