膨胀性黄土隧道洞口稳定性的可靠度分析

Reliability Analysis for Stability of Tunnel Entrance in Expansive Loess

针对山西太原小河沟膨胀性黄土隧道塌方事故,采用毕肖普法对隧道洞口仰坡塌方原因进行了分析。结合收敛约束法与蒙特卡洛法,提出了一种新的隧道可靠度分析方法,进一步分析了隧道洞口仰坡塌方原因及隧道稳定性。结果表明:隧道洞口仰坡塌方原因是仰坡滑塌推倒隧道支护,而非隧道支护承载力不足;隧道可靠度与膨胀力呈线性关系,随着膨胀力的增大,隧道失稳风险增加。

According to the tunnel collapse accident in the expansive loess of Xiaohe gully in Shanxi Taiyuan,the front slope collapse causes of tunnel entrance was analyzed by bishop method. A new analysis method of tunnel reliability was proposed by combining the convergence constraint method and Monte Carlo method,and front slope collapse causes of tunnel entrance and the stability of the tunnel were further analyzed. The results show that front slope collapse causes of tunnel entrance is not insufficient supporting capacity of tunnel support,but the front slope sliding and tunnel support collapsing,there is a linear relationship between the reliability of the tunnel and the expansive force,and the risk of tunnel instability increases with the increase of expansion force.