高应力下花岗岩双面剪切应力-应变及声发射特征

摘要

Three-axis servo testing machine,rock double shear device and acoustic eluission system were used to test the mechanical characteristics and acoustic emission characteristics of the whole failure process of granite under the action of double shear load.Test results show that:When normal stress is low (＜50 MPa),the double shea stress and strain of the rock are divided into 4 stages,named load adjustment section,elastico deformation section,elastico plastic deformation section and post-peak deformation section.When normal stress is higher (＞50 MPa),the double shear stress and strain of rock show one more section of plastic deformation strengthening section than those when the normal stress is low.The acoustic emission signals at different stages of rock shear failure have obvious characteristics.%利用真三轴伺服试验机、岩石双面剪切装置和声发射系统进行了花岗岩的双面剪切实验,测试了花岗岩在双面剪切载荷作用下破坏全过程的力学特征以及内部破裂的声发射特征.试验结果表明:当法向应力较低(＜50 MPa)时,岩石双面剪切应力应变全过程分为4个阶段,即加载调整段、弹性变形段、弹塑性变形段和峰后变形段.当法向应力较高(＞50 MPa)时,岩石双面剪切应力应变全过程比法向应力较低时多出一段塑性变形强化段.岩石剪切破坏各个阶段的声发射信号具有明显的特征.