大断面双层双跨平顶直墙暗挖地铁风道施工时具有开挖跨度相对较大，临时支护体系繁多，二次结构受力转换复杂的特点，针对北京地铁4号线石榴庄路站1#风道双层段的工程实践，分析总结大断面双层双跨平顶直墙结构中洞法开挖、受力转换、分块模筑等施工的几个关键技术环节，经实践检验，方案是合理的，可行的。

The construction of mined Metro ventilation gallery with large crosssection, double storey, double span, flat roof and upright wall has such features as relatively large excavation span, complex temporary support system and complex loadshifting of the secondary lining structure. Taking the construction of the doublestorey section of No. 1 ventilation gallery of Shiliuzhuang Road Station on Line 4 of Beijing Metro as example, the authors summarize the key construction technology for the ventilation gallery with large crosssection, double storey, double span, flat roof and upright wall in terms of central drift excavation method, load shifting and sectionbysection construction of the insitu cast concrete lining. The project practice shows that the construction plan is reasonable and feasible.