复杂应力路径下三峡库区砂岩力学特性分析  

Analysis of Mechanical Properties of Sandstone in Three Gorges Reservoir Area Under Complex Stress Paths

作　　者：王兴霞[1] 

机构地区：[1]三峡大学水利与环境学院,湖北宜昌443002

出　　处：《水利与建筑工程学报》2015年第2期99-102,共4页Journal of Water Resources and Architectural Engineering

基　　金：国家自然科学基金项目(51279091);宜昌市自然基础科学研究与应用专项项目(A14-302-a01);三峡大学青年科学基金项目(KJ2012B027)

摘　　要：针对三峡库区中砂岩进行了三轴加载试验,及不同应力路径的三轴卸荷试验。试验结果表明:与加载破坏相比,卸荷破坏岩样表现出较强的脆性。卸荷作用引起了岩样变形模量、内摩擦角、黏聚力等力学参数的劣化,从而导致岩样质量的降低。卸荷路径不同时卸荷阶段应力-应变曲线形态有很大区别。按照轴压、围压等速率减小的路径卸载,卸荷阶段应力-应变曲线呈下凹形态且出现回弹变形,回弹变形占卸荷段总变形的比例随初始围压值的增大而减小。Triaxial compression tests and unloading confining tests were conducted with the medium sandstone of Three Gorges Reservoir as test rock samples. The results indicate that the sandstone sample undergone unloading failure is more brittle than that from the loading failure. Unloading failure leads to the deterioration of rock sample mechanical parameters,namely deformation modulus,internal friction angle,and cohesion,which means lower quality of the rock sample. Shapes of unloading stress-strain curves are very different due to different unloading paths. When the maximum and minimum stresses decrease simultaneously,curves of unloading stage concave downward,and springback deformations occur. In addition,springback deformations decrease with the increase of initial confining pressure.

关 键 词：卸荷 回弹变形 卸荷变形模量 卸荷抗剪强度参数 

分 类 号：TV541[水利工程—水利水电工程]