依据岩爆发生时的力学状态,岩爆可以分为应变岩爆和冲击岩爆两大类型。冲击岩爆是深部岩体受静荷载和冲击动荷载共同作用所致,其试验系统的研发是岩石力学界的难题之一。设计并研发冲击岩爆试验系统,并进行冲击岩爆试验。该试验系统设计16种简谐波,通过其组合叠加,可以实现对开挖爆破、顶板垮落、断层滑动等冲击扰动波的模拟。试验采用加载至三向不同应力状态下的带圆形贯穿孔洞的立方体砂岩试样,在σ1方向施加扰动波,σ2,σ3保持在恒定应力水平的加载方式,通过伺服控制系统,实时采集砂岩试样冲击岩爆过程中的力和位移数据,获得全过程三向应力-应变曲线。通过图像采集系统,实时拍摄砂岩冲击岩爆全过程,获得该类型岩爆过程剥离、弹射等特征现象。并进行类似的静力加载破坏试验,观察其破坏现象与冲击岩爆过程的差异。通过对巷道单元岩体动应力和能量的分析,建立冲击岩爆的动应力和能量判别方法。
Rockbursts can be classified into the strain and impact ones according to the mechanical state upon occurring. Impact rockburst is caused by the combined static and dynamic loads in deep excavation. To develop an experimental system for simulating the impact rockburst is a very challenging issue in rock engineering. 16 simple harmonic waves together with their combinations and superimpositions were implemented in the experimental system developed and described here so that the impact wave disturbance due to the excavation blasting,the roof collapse and the fault slip etc.,could be simulated. The cubic sandstone with a circular-through-hole was initially loaded with triaxial stresses in different directions. The dynamic cyclic loading was then applied inσ1 direction, keeping the loads inσ2 andσ3 directions at constant stress level meanwhile. The data of forces and displacements during the process of impact rockburst were collected in real-time through the servo control system,so that the curve of triaxial stress-strain was obtained. The image acquisition system recorded the whole process of impact rockburst in real-time for analyzing the characteristics of spalling and ejection. The rockburst due to the static loading was carried out and was compared with the one caused by the dynamic loading. A discriminant of dynamic stress and energy for impact rockburst were established through the analysis of the dynamic stress and energy of the rock mass element in roadway.