深部灰岩力学性质及残余强度试验研究

Experimental Studies on Rock Properties and Residual Strength of Deep Limestone

在MTS试验系统上对采自凡口铅锌矿深部的灰岩进行了准静态单、三轴压缩试验,获得了不同围压下灰岩峰值强度前后的应力-应变关系曲线。根据试验结果,分析了岩石在不同围压下的受力变形特征,岩石的峰值强度前弹性模量、峰值强度与围压之间的特性,给出了峰值强度、峰值应变与围压、应力之间的量化关系。研究了岩石峰值强度后的应变软化特点和残余强度,并建立了残余强度、初始残余应变与围压之间的量化关系,得出在准静态加载条件下大多数岩样峰后产生弹脆性"跌落式"软化的重要特点,为该矿深部岩体工程应用研究中的岩石本构模型理论研究提供依据。

Quasi-static uniaxial and triaxial compressive tests for the limestone from Fankou Zinc-lead Mine are carried out through MTS Testing System,and the stress-strain curves of limestone samples before and after the peak value under different confining pressures are obtained. According to the testing results,the loading-displacement behaviors of rock samples,and the characteristics between elastic moduli,peak-strength and confining pressures before peak value of the rocks are analyzed.The quantitative relationships between peak strength and peak strain,confining pressure and stress are proposed respectively.Then the further studies on strain-softening and residual strength of rock samples after peak strength are carried out,and the quantitative relationships between residual strength,initiating residual strain and confining pressures are established. An important strain-softening property of ＂ elastic-fragile drop＂ is obtained for most of the rock samples under the quasi-loading conditions. It offers the basis for theoretical study on constitutive model of deep rock of the mine in engineering application.