爆破掘进巷道支护锚杆的振动响应研究

摘要

In order to study the influence of underground blasting seismic waves on the bolt supporting structure, in this paper, the dynamic response characteristics of the end anchored bolt under blasting load are studied by using the structural dynamics theory. Bolt stress state is different when the bolt length is different. The vibration will induce axial deformation and bending deformation in the bolt. For same bolt length, the bending deformation was bigger than axial deformation. Thus, the bending deformation was the leading deformation in the bolt. The bolt segment near the tunnel may be under pressure or tension, but the whole bolt is under tension when the bolt is longer. Whether axial force or shear in bolt is relatively small, which means that blasting vibration generally does not cause bolt damage and failure. The results have some significance to improve safety blasting technology.%为了研究爆破掘进施工对巷道支护锚杆的影响,本文采用结构动力学理论,从理论上推导出了锚杆在动荷载作用下的运动规律,计算出锚杆上的轴力与剪切力变化;分析研究了端锚式锚杆在爆破动荷载作用下的动力响应特征.结果表明:不同锚杆长度时锚杆受力状态不同,锚杆会产生的轴向变形和弯曲变形,对于同一长度的锚杆,弯曲变形要大于轴向变形,因此锚杆是以弯曲变形为主导形式.靠近巷道的锚杆段可能受压也可能受拉,但锚杆较长时锚杆整体受拉,且无论轴力还是剪力都比较小,也就是说爆破振动扰动一般不会使锚杆产生破坏失效.成果对掘进爆破安全技术的提高具有一定的指导意义.