隧道锚洞室施工对高陡边坡稳定性影响分析

Analysis on Influence of Tunnel Anchor Cavity Construction on Stability of High and Steep Slope

为评价绿汁江特大桥隧道锚洞室开挖对仰坡整体稳定性的影响,建立FLAC3D数值分析模型,模拟隧道锚洞室开挖所产生的静力效应与爆破动力效应;将主缆设计荷载作用于模型,模拟围岩应力、位移与塑性区分布规律。结果表明:在降雨工况+左侧隧道锚洞室开挖条件下,隧道仰坡稳定性系数为1.35;降雨工况+主缆设计荷载作用时,隧道仰坡稳定性系数1.29。隧道仰坡围岩在隧道锚洞室开挖过程中最不利荷载工况下,整体处于安全稳定状态。

In order to evaluate the influence of anchor cavity excavation on the overall stability of the front slope of Lvzhijiang Large Bridge tunnel,a FLAC3D numerical analysis model was established to simulate the static effect and blasting dynamic effect of tunnel anchor cavity excavation.The design load of main cable is applied to the model to simulate the distribution of stress,displacement and plastic zone of surrounding rock.The results show that the stability coefficient of the tunnel front slope is 1.35 under the condition of rainfall and the excavation of the left tunnel anchor cavity.The stability coefficient of the tunnel front slope is 1.29 under the rainfall condition and the design load of the main cable.The surrounding rock of the tunnel front slope is in a safe and stable state under the most unfavorable load condition during the excavation of the tunnel anchor cavity.