含充填椭圆形孔洞砂岩力学破坏特性试验研究  

Experimental study on mechanical and failure characteristics of sandstone with a filled elliptical hole

作　　者：周亚楠[1] 朱泉企 李地元[1] 马春德[1,2] ZHOU Yanan;ZHU Quanqi;LI Diyuan;MA Chunde(School of Resources and Safety Engineering,Central South University,Changsha 410083,China;Center for Advanced Study,Central South University,Changsha 410083,China)

机构地区：[1]中南大学资源与安全工程学院,湖南长沙410083 [2]中南大学高等研究中心,湖南长沙410083

出　　处：《铁道科学与工程学报》2019年第8期1931-1939,共9页Journal of Railway Science and Engineering

基　　金：国家重点研发计划项目(2016YFC0600706);国家自然科学基金资助项目(51474250);新疆维吾尔自治区重大科技专项项目(2018A03003-2)

摘　　要：为研究充填物力学性能对含椭圆形孔洞岩石力学破坏特性的影响,通过在预制孔洞内填充不同配比的水泥砂浆,对含充填椭圆形孔洞板状砂岩试样进行单轴压缩试验,并借助声发射系统和数字图像相关技术记录并分析试样的破裂过程和裂纹扩展特征。研究结果表明:含椭圆形孔洞试样的强度和弹性模量相对于完整试样分别降低了24.45%和23.05%,而充填后试样的起裂应力、峰值应力和弹性模量均有所提高,且提升幅度随充填物本身力学性能的增强而增大。充填作用对岩样的裂纹起裂、扩展及最终破坏形态的影响也很明显,含椭圆形孔洞试样的破坏模式随充填物力学性能的增强由拉伸破坏向剪切破坏转变。通过将声发射技术与数字图像相关技术相结合应用,能够建立起岩石宏观力学响应与细观力学行为之间的关系。In order to study the effects of mechanical performances of filling materials on failure and mechanical properties of rock with elliptical holes,uniaxial compression tests were conducted on prismatic sandstone specimens containing an elliptical hole filled with different proportions of cement mortar.Acoustic emission (AE) and digital image correlation (DIC) techniques were applied jointly to record and analyze the fracture process and crack behavior of specimens.The results show that the strength and elastic modulus of the specimen with an elliptical hole are reduced by 24.45% and 23.05%,respectively,compared with the intact specimen.While the initial stress,peak stress and elastic modulus of the specimen after filling are improved,and the improve extent increases with the increase of the mechanical properties of the filling material itself.It is found that the effects of filling on crack initiation,propagation,coalescence and ultimate failure morphology of rock specimens are also obvious.The failure mode of specimens with an elliptical hole changes from tensile failure to shear failure with the increase of mechanical properties of fillings.In addition,the relationship between macro-mechanical response and micro-mechanical behavior of rock can be established by using AE and DIC methods.

关 键 词：岩石力学 充填孔洞 力学特性 破坏过程 数字图像相关 声发射 

分 类 号：TU458[建筑科学—岩土工程]