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为控制原位扩建隧道爆破开挖对邻近运营隧道结构安全的影响,以国内罕见的大帽山大断面小净距隧道原位扩建施工为背景,从炸药直接起爆的角度,利用ANSYS/LS-DYNA软件建立了邻近运营隧道情况下隧道原位扩建爆破效应的数值计算模型,分析了爆破应力波在围岩和运营隧道衬砌中的传播规律。数值分析表明:围岩破坏应变的大小对计算结果影响较大,通过数值模拟与爆腔尺寸经验公式计算结果的比较得到了围岩的合理破坏应变值;运营隧道迎爆面拱顶及侧墙中部动力响应显著,邻近运营隧道衬砌的破坏主要是由质点振速超过安全允许值造成的;通过不同装药量爆破数值模拟结果的分析,提出了大帽山隧道原位扩建爆破最大段的控制药量。
In order to control the impact of blasting excavation in situ on the structural safety of the adjacent tunnels, based on the in situ expansion of the Taihan Mountain large section and small clear distance tunnel in China, from the point of direct detonation of explosives, ANSYS / LS-DYNA The numerical simulation model for the blasting effect of the tunnel in situ adjacent tunnels is established by software. The propagation of blasting stress waves in the surrounding rock and tunnel lining is analyzed. The numerical analysis shows that the magnitude of the failure strain of surrounding rock has a great influence on the calculation results. The reasonable damage strain value of the surrounding rock is obtained by comparing the results of numerical simulation with the empirical formula of the cavity size. The central dynamic response is significant. The damage of the tunnel adjacent to the operating tunnel is mainly caused by the vibration speed of particles exceeding the allowable safety value. Based on the numerical simulation of blasting with different charges, the maximum section control of DaMaShan tunnel Dosage.