小净距隧道爆破振动效应数值模拟分析

Numerical Simulation Analysis of Blasting Vibration Effect in Small Clear Distance Tunnel

为了分析小净距隧道爆破围岩动力响应,通过数值仿真模拟了不同中夹岩厚度和施工超前距离下隧道爆破,分析了围岩及先行洞隧道衬砌的应力、振动速度变化规律。结果表明:不同中夹岩厚度隧道,围岩应力随着中夹岩厚度的增大而较小,且主要分布在中夹岩墙和拱底部位;不同施工超前距离的隧道,随着超前距离的增大,先行洞隧道衬砌不同部位的振动速度呈"V"型分布,得出了安全合理的小净距隧道爆破施工超前距离,可供同类工程参考。

In order to analyze the dynamic response of surrounding rock in small-space tunnel blasting, the blasting of tunnels under different tunneling thickness and construction lead distance is simulated by numerical simulation. The variation of stress and vibration velocity of surrounding rock and lining of prior tunnel is analyzed. The results show that the surrounding rock stress is smaller with the increase of the thickness of the middle-slung tunnel, and the stress is mainly distributed in the middle-clip rock wall and the bottom of the arch. With the increase of the lead distance, the vibration velocity of different parts of the tunnel of the first tunnel is "V" type distribution,and the safe and reasonable advance distance of the blasting construction of the small clear tunnel is obtained, which can provide reference value for similar projects.