重复爆破荷载作用下岩石动态疲劳损伤特性研究

本课题针对岩石开挖工程广泛关注的爆区附近围岩稳定问题,开展重复爆破荷载条件下岩石动态疲劳损伤特性研究。通过设计一套实现重复爆破荷载加载试验装置进行试验，研究重复爆破荷载弹性波作用下岩体疲劳损伤特征、裂纹分形演化和疲劳强度变化规律，将裂纹扩展规律和疲劳累积损伤演化统一起来，定义与多次爆破载荷相对应的"疲劳损伤因子"；并进一步分析研究疲劳参数对岩石疲劳劣化的机理和对岩石疲劳损伤寿命的影响。通过编制XFEM（扩展有限元）程序对岩石动态疲劳损伤特性、断裂特性和裂纹扩展进行数值模拟研究，为岩石开挖工程围岩安全控制提供科学依据和实用手段。

This topic is about the problem of the stability of the rock surrounding near the blasting area which caught many attentions by the engineering of rock excavation, and studied the dynamic fatigue damage characteristics of the rocks under many times of blasting load. We studied the fatigue damage characteristics of the rock, the fractal evolution of crack and the fatigue strength under blasting load elastic wave characteristics through designed a testing apparatus which can do many times blasting load experiments. The law of crack propagation and the fatigue cumulative damage evolution were unified, and we defined “Fatigue damage factor” to correspond with Many times blasting load, and further analyzed the influence from Fatigue parameters to the mechanism of rock fatigue degradation and Rock fatigue damage life. The numerical simulation is researched on Dynamic fatigue damage characteristics of rock, fracture characteristics and crack propagation combining with XFEM simulation technique, which provide the scientific basis and practical methods to Rock excavation engineering safety control of surrounding rock.