煤矿掘进巷道爆破作业对通风构筑物的破坏作用

THE DAMAGE EFFECTS ON VENTILATION STRUCTURES IN MINE EXCAVATION ROADWAY DURING BLASTING OPERATION

本文利用爆炸力学、爆炸动力学、材料力学和结构力学等理论,建立了爆破作业过程中产生的冲击波在掘进巷道内传播的物理模型和数学模型。爆炸后波阵面是以超声速在传播;波阵面压力将衰减为当地大气压力,爆炸冲击波波阵面上的压力衰减强度基本上取决于巷道断面和巷道表面的粗糙性。当爆炸冲击波在平直巷道运动时,一些不可逆的损失和巷道表面摩擦会消耗传播过程中波的能量;而爆破作业中炸药爆炸时产生的冲击波对周围距离不同的通风构筑物产生不同程度的破坏和损伤。它不仅与冲击波的作用情况有关,而且与通风构筑物的形状、大小、自振周期等因素有关。为了避免爆炸冲击波对有明显作用的通风构筑物的破坏和人员的伤亡,井下应该减少不必要的障碍物和通风构筑物。

According to the theories of the dynamics of explosion, fluid mechanics, explosion mechanics and structural mechanics, this paper sets up the physical and mathematical models of shock wave propaga tion in the excavation roadway. Propagating at a supersonic speed after explosion, the pressure of shock wave front will degenerate to the atmospheric pressure gradually. Basically, the degree of pressure degeneration in the shock wave front is not only decided by the tunnel section but also by the roughness of the tunnel surface. Some parts of wave energy are consumed in such an irreversible loss as heating the air, and some are in the course of friction with the tunnel surface while the shock wave moves along the horizontal tunnel. While the shock wave reacts on the surroundings in different distances, the degree of damage differs widely. It is a very complicated problem that is not only related to the shock wave interaction, but also to the shape, size and natural frequency of the ventilation structure. These findings of the research have led to the conclusion that the unnecessary structures and obstacles should be moved in case of accelerating the shock wave to destroy the useful structures. Most important of all, measures should be taken to prevent the advantageous structures and workers from more serious damage.