为揭示地震荷载作用下浅埋隧道的稳定性,基于极限分析上限法,结合拟静力法,构建了浅埋隧道刚性块体破坏模式,并推导了隧道顶部支护反力q的理论表达式。基于理论公式,编制了Matlab计算程序,计算分析了不同地震水平方向峰值加速度ah时浅埋隧道的稳定性。研究结果表明:隧道顶(底)板与侧墙支护反力随着地震水平方向峰值加速度增大而增大,且地震水平方向峰值加速度越大,变化趋势愈显著;隧道顶(底)板支护反力随着侧压力系数K增大而减小,而隧道侧墙支护反力随着侧压力系数足增大而增大。研究结果可为指导浅埋隧道极限抗震能力设计提供新的思路。
To reveal the stability of shallow tunnel under seismic loads,based on the limit analysis upper bound method and the pseudo static method, the failure mode of the rigid block in the shallow rec- tangular tunnel was constructed,and the theoretical expression of the rock pressure q was derived. Based on the theoretical formula,the Matlab calculation program was compiled, and the stability of the shallow tunnel was calculated by analyzing the peak acceleration ah of seismic horizontal direction. Research results show that:The supporting force of tunnel top(bottom) plate and side wall increased with the peak acceleration of seismic horizon- tal direction. Moreover,the peak acceleration of seismic horizontal direction is greater, and the change trend is more obvi- ous. At the top (bottom)of the tunnel, the supporting force decreased with the lateral pressure coefficient K, but the support- ing force increased with the lateral pressure coefficient K at the side wall of the tunnel. The research results can provide a new way for the design of the ultimate seismic capacity of shallow tunnels.