复杂条件下浅埋暗挖隧道变形监测与控制

Deformation monitoring and control of shallow underground tunnel under complex conditions

地铁出入口暗挖过街通道一般具有埋深较浅、交通动荷载大及周边管线复杂等特点。以南京地铁1号线北延工程二桥公园站2号出入口过街通道为例,对暗挖施工过程中的变形进行监测分析。结果表明:暗挖通道的结构变形与地面动荷载有着直接关系,通过路面铺设钢板和洞内加固措施确保掌子面稳定性;CRD预留核心土分步开挖法,有效的减少了通道底部浅埋污水管卸载变形风险;及时封闭成环是控制暗挖通道变形和污水管变形渗漏的有效途径。

The characteristics of subway underground crossing generally is shallow depth,large dynamic load and complex surrounding pipelines.This paper takes Erqiao park-station’s No.2 entrance of Nanjing Metro Line 1 North Extension Project as an example,monitoring analysis of the deformation in the process of underground excavation.The results show that:ground dynamic load directly affects the structural deformation of underground tunnels,the laying of steel plate and reinforcement in the hole can ensure the stability of the palm face.CRD method can effectively reduce the deformation risk of the shallow buried sewage pipe at the bottom of the channel.Closed loop is to control the deformation of underground running tunnel deformation and sewage pipe leakage.