针对平顶直墙条件下浅埋暗挖通道开挖和二次衬砌施工风险，对平顶直墙结构断面适用条件进行分析。结合国内某城市地铁车站暗挖通道设计实践，综合考虑跨度、开挖方法、风险、工期等因素，对3种不同二次衬砌施工方法进行综合比较，对其优缺点及适用条件进行总结。结合工程实施，提出不拆撑条件下的平顶直墙暗挖结构二次衬砌施工方法和步骤，总结了平顶直墙暗挖设计要点，并提出节点处理原则。

The excavation and secondary lining of flatroof straightwall tunnels with shallow overburden have great risks. In the paper, the applicability of the flatroof straightwall tunnels is analyzed. Three methods for the installation of the secondary lining of flatroof straightwall tunnels are compared in terms of span, excavation method, risk and construction period, with a mined flatroof straightwall underpass of a Metro works as an example. The advantages, disadvantages and application conditions of the mentioned three methods are summarized. The installation method and steps for the secondary lining of mined flatroof straightwall structures under the condition that the support is not removed are proposed. The key points of the design of mined flatroof straightwall tunnels are summarized and the principle for the node treatment is proposed.