CAJ | 학술논문

为深入研究双面剪切荷载作用下岩石断裂过程声发射特性，利用自主研发的煤岩双面剪切试验装置及 PCI–2型声发射系统，分析砂岩声发射特性随含水率增高声发射特性曲线变化趋势。试验结果表明：砂岩试件在不同含水率条件下，其剪应力随时间变化趋势一致，剪应力达到峰值所需时间随含水率增加呈减少趋势；双面剪切荷载作用下，砂岩的Hit率–时间曲线、累计Hit数–时间曲线均可分为3个阶段，且Hit率峰值滞后于剪应力峰值；砂岩在双面剪切荷载作用下，内部微裂纹萌生、扩展主要始发生于剪应力达到抗剪强度的1/2时，此时砂岩试件处于微破裂稳定发展阶段；砂岩声发射事件幅值由低到高随剪应力增加呈阶梯状分布；砂岩内部微裂纹扩展方式以绕晶而过为主，穿晶破裂为辅。
위심입연구쌍면전절하재작용하암석단렬과정성발사특성，이용자주연발적매암쌍면전절시험장치급 PCI–2형성발사계통，분석사암성발사특성수함수솔증고성발사특성곡선변화추세。시험결과표명：사암시건재불동함수솔조건하，기전응력수시간변화추세일치，전응력체도봉치소수시간수함수솔증가정감소추세；쌍면전절하재작용하，사암적Hit솔–시간곡선、루계Hit수–시간곡선균가분위3개계단，차Hit솔봉치체후우전응력봉치；사암재쌍면전절하재작용하，내부미렬문맹생、확전주요시발생우전응력체도항전강도적1/2시，차시사암시건처우미파렬은정발전계단；사암성발사사건폭치유저도고수전응력증가정계제상분포；사암내부미렬문확전방식이요정이과위주，천정파렬위보。
For thefurther study of acoustic emission characteristics of rock breaking under double shear loading condition,this paper will use independent developed coal rock double shear test device and PCT–2 acoustic emission system to explore the sandstone′s acoustic emission characteristics with the increase of water content. The results show that under different rates of water content the changes of the shear stress are same with the time trend. The time reaching the peak decreased when the rate of water content increased. Under the double shear loading,sandstone Hit rate-time curve and accumulative Hit number-time curve can be divided into three stages, the Hit rate peak lags behind the peak value of the shear stress and the extreme points of Hit rate increased when the rate of water content heightened. Under the double shear loading,the internal micro crack initiated and expended when the shear stress is at the 1/2 of the shear strength. At that time the sandstone is in the steady micro rupture development stage and the expending mode of the internal micro crack is mainly around the crystal and the rupture.The extension of internal micro cracks was mainly around the crystals and the last small passed through them.