三轴应力下水对泥质砂岩力学特性影响的试验研究  

Experimental study of influences of water on mechanical behaviors of argillaceous sandstone under tri-axial compression

作　　者：周辉[1,2] 宋明 张传庆[1,2] 杨凡杰 路新景[3] 房后国 邓伟杰[3] ZHOU Hui;SONG Ming;ZHANG Chuan-qing;YANG Fan-jie;LU Xin-jing;FANG Hou-guo;DENG Wei-jie(State Key Laboratory of Geomechanics and Geotechnical Engineering,Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan,Hubei 430071,China;University of Chinese Academy of Sciences,Beijing 100049,China;Yellow River Engineering Consulting Co.,Ltd.,Zhengzhou,Henan 450003,China)

机构地区：[1]中国科学院武汉岩土力学研究所岩土力学与工程国家重点试验室,湖北武汉430071 [2]中国科学院大学,北京100049 [3]黄河勘测规划设计有限公司,河南郑州450003

出　　处：《岩土力学》2022年第9期2391-2398,共8页Rock and Soil Mechanics

基　　金：国家重点研发计划资助(No.2019YFC0605103,No.2019YFC0605104);国家重点基础研究发展计划项目(973计划)(No.2014CB046902)。

摘　　要：复杂应力状态下泥质砂岩遇水软化,严重降低围岩承载力,导致围岩破坏范围和变形压力增大,严重威胁输水隧洞运行期安全。为此,以兰州水源地输水隧洞泥质砂岩为研究对象,开展了不同浸润时间下的三轴压缩试验研究。试验结果表明,随着浸润时间的延长,泥质砂岩岩样峰值强度和残余强度对围压的敏感程度逐渐降低,水在一定程度上降低了峰值强度和残余强度对围压的敏感程度;浸润前期,残余强度随浸润时间的降低速率明显小于峰值强度随浸润时间的降低速率,水对泥质砂岩岩样峰值强度的软化作用较为明显;泥质砂岩岩样的峰值强度、残余强度和弹性模量均随浸润时间的增长呈负指数关系减小;随着围压的升高,浸润时间对弹性模量的影响程度逐渐减弱,围压升高在一定程度上降低了水对泥质砂岩岩样弹性模量的软化作用。The water softening of argillaceous sandstone in complex stress state will seriously reduce the bearing capacity of surrounding rock,resulting in the increase of failure range and deformation pressure of surrounding rock,and finally seriously threaten the safety of water tunnel during operation.To solve this problem,triaxial tests under different immersion time are carried out to investigate by using argillaceous sandstone from water delivery tunnel of Lanzhou water source project.The results are as follows.As the immersion time prolongs,the sensitivity of peak strength and residual strength to confining pressure decreases gradually.This may be attributed to the fact that the water reduces the sensitivity of peak strength and residual strength to confining pressure to a certain extent.In the early stage of immersion,the decreasing rate of residual strength with immersion time is significantly less than that of peak strength with immersion time,and the softening effect of water on the peak strength of argillaceous sandstone is more remarkable.The peak strength,residual strength and elastic modulus of argillaceous sandstone samples decrease with the increase of immersion time in a negative exponential relationship.With the increase of confining pressure,the influence of immersion time on elastic modulus gradually weakens,and the increase of confining pressure reduces the softening effect of water on the elastic modulus of argillaceous sandstone to a certain extent.

关 键 词：泥质砂岩 水 三轴压缩试验 力学特性 

分 类 号：TU411[建筑科学—岩土工程]