隧道开挖对边坡稳定性的影响规律

Inf luence of Tunnel Excavation on Side-slope Stability

隧道通过破碎带、边坡等不良地质段时,开挖过程中易发生边坡滑塌、隧道冒顶等灾害。以一高速铁路隧道下穿边坡工程为依托,通过模型试验和数值模拟研究隧道开挖过程中围岩、边坡的应力和位移变化,进而分析其对边坡稳定性的影响。分析结果表明:隧道开挖对边坡的位移影响明显,在开挖完成后拱顶处于临空状态时边坡和围岩的稳定性受到的影响最大,数值分析与模型试验结果有较好的一致性。建议先做好稳定边坡的工作,在隧道施工时应及时调整支护方案,减小开挖扰动,防止滑坡灾害。

While a tunnel is passing through unfavorable geology areas such as fracture zone,side slope and so on,the tunnel excavation often causes landslide,tunnel roof fall etc.On the basis of the example that a high speed railway tunnel will pass through a side-slope,the stress and displacement change of tunnel surrounding rock and side-slope during tunnel excavation were studied by model experiment and numerical simulation.The results show that tunnel excavation obviously affects side-slope displacement,the stability of tunnel and side-slope were reduced mostly while the excavation was completed but vault was still not supported.The result of numerical simulation agrees well with that of model experiment.It is suggested that measures should be taken to strengthen the side-slope stability before tunnel construction,and the support scheme should be adjusted timely to reduce the excavation disturbance and to avoid landslide.