富水岩溶区隧道循环爆破所致围岩累积损伤的超声检测

Ultrasonic testing of cumulative damage of surrounding rocks caused by cyclic blasting in water-rich karst areas

为研究富水岩溶区隧道爆破开挖带来的围岩损伤累积规律,对多次循环爆破作用下的隧道围岩进行累积损伤超声检测和振动监测试验,分析了其累积损伤演变规律、影响范围以及质点峰值振速与爆源距离的关系。试验结果表明,爆破对隧道围岩的影响深度为1.2 m,在相同装药量情况下,随着隧道掌子面的推进,爆破对围岩的扰动在第5次爆破后逐渐减弱,距离爆源23 m内为爆破作用的影响范围。该试验结果可为穿越富水岩溶区隧道的安全开挖、支护结构稳定性分析提供参考。

To study the cumulative damage law of surrounding rock caused by tunnel blasting excavation in watery karst area, the nondestructive testing field test based on ultrasonic detection and vibration monitoring is used to monitor the cumulative damage and vibration of tunnel surrounding rock under multiple cyclic blasting, and the evolution law of cumulative damage of tunnel surrounding rock under multiple blasting is analyzed. The experimental results show that the influence depth of the blasting on the tunnel rock is 1.2 meters. With the same loading amount, the disturbance of the blasting on the tunnel surrounding rock gradually weakens after the fifth blasting, within 23 meters from the blasting source. The test results can provide a reference for the safe excavation of tunnel blasting and the stability analysis of support structure through watery karst area.