一种测量岩石压缩裂纹扩展过程声波波速的连续测量方法

A CONTINUING MEASURE METHOD FOR ACOUSTIC WAVE VELOCITY MEASUREMENT DURING CRACKING PROCESSES OF ROCK

中低围压或单轴压缩荷载条件下,可以将脆性岩石材料的裂纹扩展过程划分为原生裂纹压密、新生裂纹起裂并稳定扩展、不稳定裂纹扩展和交互贯通以及峰后5个主要发展阶段。含预制裂纹试样的直接观测法、应变监测、声发射(AE)监测、声波波速测试、CT(computerized tomography)扫描、微电镜观察等间接监测方法被用来研究裂纹起裂和扩展过程。本文基于在中、低围压以及单轴压缩荷载条件下,脆性岩石材料首先产生张拉裂纹,并优先沿加载方向发育的规律,提出采用声波波速连续测量方法进行岩石加载过程波速的连续观测,有助于分析裂纹扩展过程中声波波速的变化,为研究裂纹扩展过程提供一种间接测量手段。

At medium and low confining stress of triaxial and uniaxial compressive load,five stages as being（ 1）crack closure,（ 2） linear elastic deformation,（ 3） crack initiation and stable crack growth,（ 4） critical energy release and unstable crack growth,and（ 5） failure and post peak behavior can be defined for brittle rock material. Direct observation on the surface of flaw contained specimens,indirect observation techniques such as strain monitoring,Acoustic emission（ AE） monitoring, acoustic wave velocity monitoring, computerized tomography scanning,microscopic observation（ SEM/ESEM） etc,. Under the compressive load,tensile cracks are the first and primary cracks,which propagate generally along the loading direction. A continuing measure method for acoustic wave velocity measurement during cracking processes of rock was proposed based the discipline of crack propagation. The method will benefit for the indirect observation of cracking processes by monitoring the changes of acoustic wave velocity.