光面爆破的岩石裂纹扩展规律研究

摘要

Smooth blasting is a controlled blasting technique.In order to achieve a more accurate control blasting effect,the law of rock crack propagation in smooth blasting was studied.In the stage of initial crack initiation of smooth blasting,the simplified model of elastic mechanics of smooth blasting was analyzed by means of numerical simulation.The starting point and the initial crack length of the initial crack were obtained,the crack was driven by the explosion gas,the initial crack expands secondarily.From the energy of crack propagation,the quantitative relationship between crack propagation velocity and crack length was analyzed.Based on the fracture mechanics,the crack secondary expansion condition and the secondary expansion range were theoretically analyzed,and the relationship between the crack secondary expansion length and pore pressure was quantitatively described.Based on the cognition of the mechanism of the smooth blasting,the calculation methods of the parameters such as the uncoupling coefficient,the distance between the blast holes and the thickness of the smooth surface in smooth blasting were proposed.%光面爆破是一种控制爆破技术,为了实现更为精确的控制爆破效果,需要对光面爆破的岩石裂纹扩展规律进行研究.在光面爆破的初始裂纹产生阶段,利用数值模拟的方法,对光面爆破的弹性力学简化模型进行分析,得到了初始裂纹的起裂点位置以及初始裂纹长度.在爆轰气体驱动下,初始裂纹二次扩展.从裂纹扩展的能量角度,分析了裂纹扩展速度与裂纹长度的定量关系.基于断裂力学对裂纹二次扩展条件和二次扩展范围进行理论分析,定量描述了裂纹二次扩展长度与孔壁压力的关系.最后,在对光面爆破致裂机理认知的基础上,提出光面爆破中装药不耦合系数、炮孔间距、光面层厚度等参数的计算方法.