爆破振动下围岩支护锚杆动力响应解析解  

Analytical solution of dynamic response of rock bolt under blasting vibration

作　　者：胡帅伟[1] 陈士海[1,2] HU Shuai-wei;CHEN Shi-hai(College of Civil Engineering,Huaqiao University,Xiamen,Fujian 361021,China;Fujian Research Center for Tunneling and Urban Underground Space Engineering,Huaqiao University,Xiamen,Fujian,361021,China)

机构地区：[1]华侨大学土木工程学院,福建厦门361021 [2]华侨大学福建省隧道与城市地下空间工程技术研究中心,福建厦门361021

出　　处：《岩土力学》2019年第1期281-287,共7页Rock and Soil Mechanics

基　　金：国家自然科学基金(No.11672112);爆炸冲击防灾减灾国家重点实验室开放课题(解放军理工大学)(No.DPMEIKF201307);华侨大学科研基金项目(No.13BS402)~~

摘　　要：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。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.

关 键 词：爆破振动 地下工程 锚杆支护 动力响应 

分 类 号：TU435[建筑科学—岩土工程]