【摘要】 为研究结构面岩体在压剪荷载作用下的声发射特征和规律,利用水泥砂浆作为模型材料制作具有不同起伏高度的不规则锯齿形结构面,研究不同起伏高度、不同剪切速率和不同法向压力下声发射参数的变化规律和发生机制。试验结果表明:结构面剪切时理想的累积撞击曲线可以划分为平静期、缓慢上升期和急剧上升期3个阶段;随结构面起伏高度的增大,发生宏观剪切破坏时能量率峰值变大、累积撞击数变小;随剪切速率的增大,能量率曲线和撞击率曲线在剪切过程中波动性增强,能量率峰值、撞击率峰值和累积能量随剪切速率的增大有减小的趋势;声发射参数随法向压力变化规律性不强,但随法向压力的增大,破坏时对应的能量率峰值和累积能量有减小的趋势,撞击率峰值和累积撞击数有增大的趋势。研究成果可为声发射技术用于监测和预报现场结构面岩体的静力或动力剪切破坏提供指导。更多还原

【Abstract】 To investigate the acoustic emission(AE) characteristics and laws of rock discontinuity under compression-shear stress,irregular serrated discontinuities with different asperity height were made of cement mortar and change laws of AE parameters and their mechanism of the discontinuities at different asperity height,shearing velocity and different normal stress are studied. Experimental results indicate that the ideal cumulative hits of discontinuity during shearing can be divided into three stages——quiet period,slow rise period and sharp growth period. It can be found that the peak energy rate increases while cumulative hits decrease with the increase of discontinuity asperity height when macroscopic shear failure occurs. With increase of shearing velocity,curves of energy rate and hit rate become higher volatility and peak energy rate,peak hit rate and cumulative energy tend to decrease. Change laws of AE parameters is not very obvious with the change of normal stress,but peak energy rate and cumulative energy tend to decrease while peak hit rate and cumulative hits increase with the increase of normal stress. Research results can provide guidance for applications of acoustic emission techniques into monitoring and prediction of the static or dynamic shear failure of in-situ rock discontinuities.更多还原