爆破振动下围岩支护锚杆动力响应解析解

为了研究爆破掘进施工对巷道支护锚杆的影响，采用结构动力学理论，从理论上推导出了锚杆在爆破地震波作用下的振动规律，计算出锚杆上的位移、振速、轴力随时间的变化，研究了黏结式锚杆在爆破动荷载作用下的动力响应特征。结果表明：自由段锚杆的轴力和轴向振速呈现指数型衰减，而锚固段锚杆的轴力和轴向振速以及剪应力呈现正弦变化，整体表现为先增大后减小。锚固长度对锚杆振动效应影响较大，不同锚固长度时锚杆受力状态不同，在锚杆满足抗拉强度的前提下，可以适当减小锚固段长度。剪切刚度对锚杆的振动有一定的影响，剪切刚度越大，锚杆与锚固砂浆之间的剪应力也越大。故为了防止锚杆不发生剪切破坏，尽量选择剪切刚度较小的锚固剂材料。研究成果对掘进爆破安全技术的提高具有一定的指导意义。

Analytical solution of dynamic response of rock bolt under blasting vibration

Aim of this study is to investigate the influence of blasting excavation construction on roadway support bolt. Based on the theory of structural dynamics, the vibration law of bolt under blasting seismic waves is deduced theoretically, including the variation of displacement, vibration speed and axial force on bolt with time. The result shows that the velocity and axial force of the bolt in the free section decrease exponentially, while the axial force, the axial velocity and the shear stress of the bolt in the anchorage section change sinusoidally, and the overall performance increases first and then decreases. The anchorage length has a great influence on the vibration effect of the bolt. The stress state of the bolt varies with the anchorage length of the bolt. On the premise that the tensile strength of the bolt is satisfied, the length of the anchorage section can be reduced appropriately. Shear stiffness has a certain effect on the vibration of the bolt. The greater shear stiffness lead to the greater shear stress between bolt rod and anchoring mortar. Therefore, in order to prevent the bolt from shear failure, the anchorage material with smaller shear stiffness should be chosen as far as possible. The research results have some guiding significance for improving the safety technology in excavating blasting.