地铁盾构侧穿既有铁路桥梁技术措施研究

Research on Technical Measure for Metro Shieldtunnel Lateral Crossing Below Existing Railway Bridge

依托地铁盾构侧穿既有铁路桥梁的工程实例,对盾构施工对铁路桥梁的影响进行了分析,介绍了不同规程、规范对铁路桥梁沉降的管理规定,采用三维有限元计算了在有无复合锚杆桩加固条件下盾构穿越铁路桥梁的沉降情况,并提出了控制沉降的技术措施:首先对铁路桥桩周围土体设置复合锚杆桩加固,以加强铁路桥桩周围土体的整体性,并对桥桩起到隔离保护作用;其次在盾构隧道设计上采用加强性管片,并增加施工预留注浆孔;最后应优化施工参数,加强监测和采用科学合理的信息化施工。

In this paper,based on the actual case of metro shield lateral crossing below the existing railway bridge,the influence between the shield construction and the railway bridge was investigated.The regulations and provisions on the settlement of bridge in different codes were introduced.Move over,analysis was made on the settlement of the shield tunneling across the existing railway bridge by means of 3D FEM in two cases,which used and no used composite anchor pile reinforcement and the following technical countermeasures were proposed：firstly,pre-reinforcement was made for the ground surrounding the pile of the bridge where shield passing through,so as to improve the ground＇s stability and isolate protection of the bridge pile;secondly,strengthened segments with preserved grouting holes are adopted in the tunnel design;thirdly,the construction parameters should optimize,strengthen monitoring and reasonable information construction should be used.