某跨铁路桥设计方案优化研究

Research on Optimization of Design Scheme of a Railway Overpass Bridge

某跨铁路桥在初步设计阶段采用了变截面预应力混凝土现浇T型刚构而后转体跨越铁路的设计方案。施工图设计阶段,为了响应业主的进一步减低造价、减少施工难度的要求,项目组对该桥的方案做了大量调查、研究和比选工作,前后与业主会同该段铁路的主管铁路局就方案进行了多次的沟通交流。方案经历了多次优化调整,最终在各方的共同努力下达成一致,采用了3跨一次现浇而后整体顶推施工的预应力混凝土现浇箱梁方案。该方案具有施工难度相对较小、安全度高、总造价低的特点,同时将对铁路运营的不利影响降低至可以接受的范围。

In the preliminary design stage of a railway overpass bridge, the design scheme of variable section with PC cast-in-situ T-shaped rigid frame and then swivel crossing the railway is adopted. In the detailed engineering design stage,in response to the owner’s requirements to further reduce the cost and reduce the construction difficulty,the project team has conducted a lot of investigation,research and comparisons on the scheme of the bridge,and multiple communications with the owner and the relevant railway authorities are conducted for many times.The scheme has undergone many optimization and adjustment,and finally the agreement is reached under the joint efforts of all parties.The scheme of prestressed concrete cast-in-situ box girder with three spans and one cast-in-place and then overall jacking construction is adopted.The scheme has the characteristics of relatively small construction difficulty,high safety and low cost,and reduces the adverse impact on railway operation to an acceptable range.