地铁车站小直径管幕工法开挖变形规律

沈阳地铁市府大路站是采用小直径管幕工法施工的地铁暗挖车站.通过有限差分软件FLAC^3D建立车站结构-地层三维模型，分析总结了小直径管幕工法动态开挖过程引起的地层及主体结构的位移变形规律.结果表明:小直径管幕工法开挖过程引起的地表沉降具有明显的阶段性，沉降槽形态在群洞效应和管幕预支护作用的影响下变化频繁，横导洞间土体开挖阶段引起的地表沉降占到了最终沉降的50.54%，该阶段是地表沉降控制的关键阶段；管幕-梁-桩-柱施工完成后，主体结构变形表现出良好的协同作用，横梁竖向变形表现为车站两端小中间大，边桩及中柱的水平位移在负二层施工期间增长显著，占到了水平位移最大值的47.1%和55.8%，该阶段是控制主体结构变形的关键阶段.

Deformation Law of Subway Station Constructed by Small Diameter Tube Curtain Method

Shifudalu station of Shenyang Metro is constructed by small diameter tube curtain construction method. The three-dimensional model of station structure and stratum was built by using FLAC^3D. The deformation laws of stratum and the main structure caused by dynamic excavation of small diameter tube curtain were analyzed and summarized. The results show that the surface settlement caused by small diameter tube curtain excavation takes on staged characteristics. Under the influence of group hole effect and pre-support of the pipe curtain， the shape of the settlement tank changes frequently. The ground surface settlement caused by soil excavation between transverse guide tunnels accounts for 50.54% of the final settlement， which is the key stage of ground surface settlement control. After the completion of tube curtain-beam-pile-column construction， the deformation of the main structure shows a good synergistic effect. The vertical deformation of the beam is small at both ends of the station and large in the middle. The horizontal displacement of the side pile and the middle column increased significantly during the negative second storey construction period， and accounts for 47.1% and 55.8% of the maximum horizontal displacement respectively. This stage is the key stage in controlling the deformation of the main structure.