本文主要利用理论分析和数值计算方法,研究浅埋无水砂卵石地层区间隧道的台阶法开挖方案优化设计,研究认为浅埋无水砂卵石地层隧道应采取短台阶开挖,以加快支护环的封闭。同时应减小土体一次暴露的长度,减少一次开挖量和出渣量,缩短开挖与支护的衔接时间。 In this paper, the theoretical analysis and numerical calculation are mainly used to study the optimization design of stepped excavation scheme for tunnels with shallow sand-free sand and gravel stratum. It is considered that the tunnel with shallow buried sand-gravel cobble stratum should be short-step excavation to speed up the support The ring is closed. At the same time should reduce the length of the soil once exposed to reduce the amount of excavation and the amount of slag, shorten the excavation and support of convergence time.