三轴压缩下茅口灰岩围压效应的试验研究  

Experimental study of confining pressure effect under triaxial compressive strength of Maokou limestone

作　　者：王亚[1,2] 万文[1,2] 赵延林[1,2] 罗世林[1,2] 唐劲舟 

机构地区：[1]湖南科技大学能源与安全工程学院,湖南湘潭411201 [2]湖南科技大学煤矿安全开采技术湖南省重点实验室,湖南湘潭411201

出　　处：《矿业工程研究》2015年第3期50-55,共6页Mineral Engineering Research

基　　金：国家自然科学基金资助项目(51174088);湖南科技大学研究生创新基金资助项目(S140002)

摘　　要：针对南方广泛存在的茅口灰岩,利用MTS815电液伺服控制刚性试验机进行不同围压下三轴压缩试验,通过拟合分析,结果表明:(1)三轴抗压强度随着围压的增大,且呈线性增长;低围压条件下,茅口灰岩弹性模量随围压增大而增大,围压超过17 MPa,弹性模量趋于稳定;泊松比随围压增加成二次非线性增长趋势.(2)低围压条件下,岩样扩容率较小时即发生脆性破坏,体积应变扩容率随着围压的增大而提高;围压为12 MPa,岩样由脆性向延性转化,围压加至17 MPa,岩样表现为延性流动.3)随着围压的逐渐增加,岩样破坏方式趋于简单,由侧向剪切破坏逐渐转为对角剪切破坏,破坏角增大.Under different confining pressure,triaxial compressive strength of Maokou limestone is tested by MTS 815 test system. Results show that( 1) with the increase of confining pressure,triaxial compressive strength increase and present linear relation. Under low confining pressure,the elastic modulus increase with the confining pressure increases,and elastic modulus tends to be stable when confining pressure is higher than17 MPa. Relationship between the Poisson ratio and confining pressure is nonlinear quadratic polynomial relations;( 2) Under low confining pressure,the fracture of rock samples is brittle fracture when expansion rate is low,and expansion rate increases with the confining pressure increasing. Confining pressure is 12 MPa,rock samples is from brittle transiting to ductile,confining pressure is 17 MPa,rock samples turn to ductile,and( 3)Fracture angles increase with the increase of confining pressure. Rupture type of rock samples changes from lateral shear fracture to diagonal shear fracture.

关 键 词：茅口灰岩 围压 三轴压缩 延性 

分 类 号：TU459[建筑科学—岩土工程]