【摘要】 冲击地压巷道爆破卸压产生的爆破应力波在巷道围岩中会产生高频扰动，使锚杆承受瞬态循环冲击，易诱发锚杆疲劳损伤和失效。针对上述问题，利用理论推导、数值模拟与井下实测相结合的手段，系统研究了爆破动载作用下锚杆的动态响应特征，通过构建爆破动载作用下锚杆一维自由振动模型，结合锚杆固有模态分析了锚杆在端锚与全锚两种锚固条件下的振型差异，建立了动载作用下的锚杆疲劳损伤演化方程，揭示了冲击动载对锚杆疲劳寿命的影响机理。研究结果表明：爆破动载会持续冲击锚杆，致使疲劳损伤累积，其损伤累积过程表现为裂纹萌生、扩展直至整体破断失效的演化规律；当动载幅值越大、频率越接近锚杆固有频率时，锚杆疲劳寿命衰减越明显；端锚相较全锚在动载作用下更易出现共振效应，导致爆破应力波振幅放大与早期失效；锚杆工作阻力损失率随至爆破源距离增加呈负指数趋势减小，爆破帮和顶板锚杆相较非爆破帮工作阻力下降明显，该研究成果为锚杆在爆破动载下的振动响应机理解析提供了新思路，对深部矿井支护系统设计、爆破参数优化及灾害防控具有重要的理论意义和工程应用价值。更多还原

【Abstract】 The blasting stress waves generated by blasting pressure relief in rock burst roadways induce high-frequency disturbances in the surrounding rock of the roadway. This subjects the bolts to transient cyclic impacts, which easily trigger fatigue damage and failure of the bolts. To address this issue, a combination of theoretical derivation, numerical simulation, and underground field measurement was employed to systematically study the dynamic response characteristics of bolts under blasting dynamic loads. A one-dimensional free vibration model of bolts under blasting dynamic loads was established, and the differences in vibration modes of bolts under two anchorage conditions(end anchorage and full anchorage) were analyzed by combining the natural modes of the bolts. Additionally, an evolution equation for bolt fatigue damage under dynamic loads was constructed, revealing the influence mechanism of impact dynamic loads on the fatigue life of bolts. The research results indicate the following: blasting dynamic loads continuously impact the bolts, leading to the accumulation of fatigue damage. This damage accumulation process follows the evolutionary law of crack initiation, propagation, and eventual overall fracture failure. The greater the amplitude of the dynamic load and the closer its frequency is to the natural frequency of the bolt, the more significant the attenuation of the bolt’s fatigue life. Compared with full anchorage, end anchorage is more prone to resonance effects under dynamic loads, resulting in the amplification of blasting stress wave amplitude and early failure of the bolts. The loss rate of bolt working resistance decreases in a negative exponential trend as the distance from the blasting source increases. The working resistance of bolts in the blasting side and roof decreases more significantly than that in the non-blasting side. The research findings provide new insights for analyzing the vibration response mechanism of bolts under blasting dynamic loads, and hold important theoretical significance and engineering application value for the support system design of deep mines, the optimization of blasting parameters, and disaster prevention and control.更多还原