开采扰动岩体力学性质变异试验研究与探测分析

EXPERIMENTAL STUDY AND DETECTION ANALYSIS OF MECHANICAL PROPERTIES VARIABILITY OF ROCK MASS IN EXCAVATION DISTURBANCE

根据弹性模量变化定义岩体损伤变量,结合室内岩石单轴全应力–应变循环加、卸载试验,探究岩石损伤过程中电阻率的变化,获得岩石单轴压缩各个阶段电阻率的变化规律,分析发现电阻率与弹性模量以及抗压强度之间的变化关系符合对数数学模型,可实现用电阻率变化表征岩体损伤变量。同时,利用刚性试验机进行大理岩三轴压缩试验,研究不同损伤状态下抗剪强度的变化规律,试验结果显示,不同损伤状态下弹性模量与抗剪强度变化关系符合对数数学模型,且整体变化规律差异不大。根据上述研究结果,最终建立损伤过程中电阻率、弹性模量、抗压强度及抗剪强度之间的经验公式,实现用电阻率变化表征扰动岩体的力学性质变异。最后,利用抚顺东露天矿边坡现场高密度电法探测结果,得出边坡地层开采扰动前后视电阻率变化,代入经验公式估算出扰动边坡岩体的力学参数,为进一步分析井工开采扰动边坡的稳定性提供岩石力学参数选取依据。

The change of resistivity of rock during its damage process is studied by uniaxial cyclic loading and unloading test. The variation rules of rock resistivity, elastic modulus and compression strength in the damage process is found out that it accords logarithmic mathematical model. So the rock damage variable can be expressed in resistivity change. The results of marble triaxial compression test show that the relationship between rock elastic modulus and shear strength accords logarithmic mathematical model; and the difference of the whole variation law is not obvious. According to the research results mentioned above, the empirical equation regarding resistivity, elastic modulus, compression strength and shear strength is established; and the variability of mechanical properties of rock mass can be expressed with resistivity change. At last, the mechanical parameters of disturbed rock mass are estimated according to apparent resistivity change of Donglutian open pit layer in Fushun got by in-situ detection, which provide basic evidence of selecting mechanical parameters for further analysis of the slope stability.