赋存深度对岩石力学参数影响的实验研究

Experimental study of the effect of depth on mechanical parameters of rock

研究赋存深度对岩石物理力学参数的影响,对于认识深部岩体变形破坏规律,以及分析深部工程灾害事故机理具有十分重要的意义.通过在北京门头沟矿区大台井同一岩层进行现场取样,获得了赋存深度处于410-1010m的7个深度水平上的同一层玄武岩,将其加工成77个标准试件（其中单压21个、三轴35个、劈裂21个）,借助MTS815和RMTS150岩石力学实验系统,分别进行了单轴压缩、三轴压缩和巴西劈裂实验,获得了玄武岩密度、单轴抗压强度、单轴抗拉强度、弹性模量、泊松比、黏聚力、内摩擦角等基本岩石物理力学参数随赋存深度的变化规律.研究发现,统计意义上玄武岩密度、弹模、单拉强度、单压强度、黏聚力、内摩擦角随赋存深度的增大而线性增加,仅泊松比随深度增加而线性减小.另外,还简要分析了造成不同深度同一岩层物理力学参数差异的原因.

Study on the effect of depth on physical and mechanical parameters of rock plays an important role in understanding the defor-mation and failure of rock at depth and analyzing the mechanism of engineering disasters at depth.In this work,basalt specimen are taken from at 7 different depths ranging from 410 m to 1010 m at Datai Coal Mine,Beijing,which are processed into 77 standard rock samples（21 for uniaxial compression tests,35 for conventional triaxial compression tests,21 for Brazilian tests）. With the rock mechanics test system of MTS815 and RMTS150,some physical and mechanical parameters are obtained,including rock density,uniaxial compressive strength,uniaxial tensile strength,elastic modulus,Poisson’s ratio,cohesion,friction angle,by uniaxial compression tests,conventional triaxial tests and Brazilian tests.The results show that,rock density,uniaxial compressive strength,uniaxial tensile strength,elastic modulus,cohesion and friction angle increase linearly with increasing depth,and there is a linear decreasing in Poisson’s ratio with increasing depth.Furthermore,the cause of the difference of physical and mechanical parameters of the same rock at different depth is analyzed.