岩石破坏前后曲线分类及脆-延转换围压研究——蚀变岩常规三轴压缩试验Ⅰ  

Conventional triaxial compression test I of altered rock:study of classification of strain-stress curve before and after destruction and brittle-ductile diversion confining pressure

作　　者：杨根兰[1,2] 黄润秋[2] 蔡国军[2] 付小敏[2] 林锋[2] 徐德敏[2] 

机构地区：[1]贵州大学资源与环境工程学院,贵州贵阳550003 [2]成都理工大学地质灾害防治与地质环境保护国家专业实验室,成都610059

出　　处：《岩土力学》2008年第10期2759-2763,共5页Rock and Soil Mechanics

基　　金：国家自然科学基金雅砻江水电开发联合研究基金重点资助项目(No.50539050)

摘　　要：蚀变岩是工程中少见的软弱岩类,在西南某重大水电工程中,蚀变岩处于工程的重要部位,为保证工程的长期稳定性,对蚀变岩力学特性进行了深入全面的试验研究。通过对孔隙度不同的饱水蚀变岩进行系统的常规三轴压缩试验和总结分析,提出了蚀变岩三轴压缩下破坏前应力-应变曲线可分为3大类,破坏后应力-应变曲线亦可分为3大类的形态模式。并得出结论:蚀变岩的破坏类型受围压与孔隙度的共同影响,在给定的12MPa围压下蚀变岩以脆性破坏为主,只有孔隙度大于16%且围压大于4MPa时才有可能进入脆-延转换状态,且脆-延转换围压随孔隙度增加而降低,临界状态应力比随孔隙度增大而增加。The altered rock is the soft rock which is scarce in the engineering. For a major engineering project in Southwest China, the altered rock is located in the key position of the project. In order to guarantee the project for long-term stability, the mechanical property of the altered rock should be deeply and fully studied. On the basis of systematic conventional triaxial compression test for the saturated altered rock under different porosities, the test results are analyzed and summarized. It has been put forward that there are three types of stress-strain curve before rock destruction and three types of stress-strain curves after rock destruction. The conclusions have been proposed that the altered rock destruction is effected by both confining pressure and porosity. When the confining pressure is 12 MPa, the brittle failure is dominating. Only when the porosity is more than 16 % and the confining pressure is more than 4 MPa, the brittle-ductile fracture diversion state is possibly found. Furthermore, the confining pressure of brittle-ductile fracture state diversion decreases along with the porosity increases; and the critical state stress ratio increases along with the porosity increases.

关 键 词：蚀变岩 常规三轴试验 曲线类型 脆-延转换 围压 临界状态应力比 

分 类 号：TU458.3[建筑科学—岩土工程]