隧道围岩爆破地震累积效应研究

Study on Blasting Seismic Cumulative Effects of Road Tunnel and Its Surrounding Rocks

针对公路隧道施工循环爆破作业展开爆破震动累积效应研究。基于现场爆破震动监测与波与能量的相关理论,提出利用单位药量与距离条件下的爆破地震波面积(单位等效面积)分析评估单位药量与距离条件下的爆破震动对结构与围岩介质的影响,通过比较质点振动速度波形面积的变化可分析评估围岩介质体中的爆破震动能的分布与药量和距离的关系,以及围岩介质体物理力学性质的改变与爆破震动能衰减的关系。并提出了爆破地震波单位等效面积的计算方法,通过非药量和距离因素影响下质点振动速度波形单位等效面积分析,合理评估单位爆破震动能在围岩体中的分布状况,以及爆破震动作用下的介质体本身物理力学性质的改变,并可推断与阐述围岩介质体中不连续结构面(体)的总体分布状况,以及在爆破震动作用下的发生与扩展情况和与爆破地震波的互相作用。

In this paper, the blasting seismic cumulative effects is explored and studied mainly for the cycling blasting in road tunnel engineering. The seismic wave and its particle velocity are used to account for and resolve engineering problems caused by blasting vibration. It is shown that the cumulative damage will take place in rock mass under the dynamic loads of blasting seismic waves after analyzing the characteristic of blasting seismic wave in propagation, energy, frequency and magnitude, and rock mass dynamic characteristic. It is pointed out that the faults in rock mass and the blasting seismic waves propagation affect each other. And there are some decline that different faults affect mainly different wave propagation. At the same time,fracture series in rock mass can be treated as a fault interface. It is confirmed that the area of particle velocity wave in rock mass can be used to explain and comment energy of blasting vibration in rock mass. The magnitude of the area of particle velocity wave changed with charges of explosives and distance correspond to the change of blasting seismic energy. Furthermore, it is also used to illustrate the change of characteristic of rock mass and attenuation of the blasting vibration energy in rock mass. Similarly, the effective unit area of particle velocity on unit charges and distance can be used to comment unit blasting vibration energy in rock mass. Here, the calculation methods of the effective unit area have been put forward. And the information of faults and its' developing state in rock mass can also be illustrated through comparing the magnitude of the effective unit area of particle velocity.