盾构下穿新建铁路站场地基预处理技术研究

研究目的:某地铁区间隧道工程为双线隧道,按规划线路需要下穿沪宁铁路轨道,盾构推进施工将引起上方铁路线路的轨面变形,影响铁路行车安全或速度,同时铁路行车也影响地铁隧道的安全。因此本文提出了采取"桩+板"方案地基预处理方案解决施工困难,并为同类下穿项目提供借鉴。研究结论:研究表明,对本地铁隧道采用"桩+板"方案加固,且采用加强配筋管片,有效控制了盾构时的铁路地面变形;施工过程中,同步注浆是关键,比正常注浆量增加0.1～0.2 m3为宜,且及时进行二次注浆,以保证地面建筑物的安全。

Research on Pretreatment Approach of Foundation for Shield Under - passing Newly- built Railway Station

Research purposes:A interval tunnel of subway is adouble-track tunnel,and it has to under-pass the Shanghai-Nanjing Railway.The shield construction will cause the deformation of the rail surface of the railway to impact the running speed and safety of the train,and also the railway transportation will influence the tunnel safety.For solving these problems mentioned above,this paper presents the"pile +plate" pretreatment approach of the foundation for providing the reference to the similar works. Research conclusions:The studies show that using the "pile +plate" pretreatment approach along with the reinforced segment for this subway tunnel can effectively control the ground deformation.In the course of construction,the synchronous grouting is a key element.And its grouting volume should be more than usual by 0.1-0.2 m3 and the second grouting should be conducted timely to guarantee safety of the ground buildings.