考虑底部隆起的浅埋隧道围岩压力计算分析

针对浅埋隧道开挖后底部隆起变形现象，应用极限分析上限法构造了考虑底部隆起变形的围岩压力计算模型，结合线性Mohr-Coulomb准则等推导出极限围岩压力的理论表达式。通过约束条件将围岩压力的计算转化为数学中的最优化问题，编制程序进行了优化计算。将计算结果与工程实测数据及文献计算结果进行了对比，验证了当前方法的可靠性。同时，指出在运用极限分析法处理浅埋隧道围岩压力问题过程中应将隧道底部一同考虑，对隧道底部支护会对整个围岩压力产生影响，有助于隧道结构的整体稳定。研究可以为浅埋隧道的开挖、支护提供一定的理论指导.

Limit Analysis of Surrounding Rock Pressure for Shallow Tunnels Considering Floor Heave

For the floor heave phenomena after excavation of shallow tunnels,the limit analysis upper bound method was applied to build a surrounding rock pressure calculation model of rigid bodies in view of tunnel floor heave effects.Then,according to the linear Mohr-Coulomb criterion and the associated flow rule,the theoretical expression of the surrounding rock limit pressure was deduced.Through constraints,the calculation of surrounding rock pressure was transformed into an optimization problem in mathematics so that a computer program was compiled to conduct the optimal computation.The calculated results were compared with the measured data and the reference results,to verify the reliability of the proposed method.The results show that,in the application of the limit analysis upper bound method to deal with the surrounding rock pressure problems of shallow tunnels,the tunnel floor heave effects shall be fully considered;the supporting of the tunnel floor has significant influence on the surrounding rock pressure.The research provides a theoretical reference for the excavation and supporting of shallow tunnels.