基于小波能量的爆破震动巷道围岩稳定性判据

Stability criterion of surrounding rock in roadway under blasting vibration load based on wavelet energy

目前爆破震动荷载作用下地下围岩稳定性判别主要依靠单一强度因子的独立阈值稳定性判据,这类判据多为定性分析,没有同时考虑爆破震动三要素的综合作用效果,且未建立稳定性判据与巷道围岩破坏程度之间的定量关系,在实际工程应用中存在一定的缺陷和不足。通过建立爆破荷载作用下的不同类别巷道围岩有限元模型,提取巷道围岩的响应信号,基于小波变换理论建立时间能量密度函数分析巷道围岩响应信号的时、频域特征,进而将时间能量密度曲线与时间轴围成的面积TEDI作为评估爆破震动效应的判别指标,建立了TEDI与巷道围岩损伤程度的定量关系,为进一步完善基于小波能量理论的巷道围岩损伤预警体系奠定基础。

The stability assessment methods of surrounding rock roof under blasting load depend on the independent threshold safety criterion about the single intensity factor,which are mostly qualitative analysis without considering the three elements of the blasting vibration,so this kind of methods has some shortcomings and the insufficiency in engineering applications.The response signals are got through the numerical model of the different surrounding rock classes under blasting loads.The time-energy density function was used to analyze the time domain and frequency domain characteristics of the response signal;and the integral of the time-energy density served as eigenvalue was used to assess the blasting vibration effect.The quantitative relationship between the time-energy density integral(TEDI)and the roof damage degree of surrounding rock set the stage for improving the early warning system of rock roof damage based on the wavelet theory.