某高速铁路主跨176m混合连续梁方案设计

Scheme Design of 176m Main Span Hybrid Continuous Beam for a High-speed Railway

某高速铁路合肥至武汉段跨越黄花涝府河采用(78.18+176+78.18)m混合连续梁。文中介绍了该桥工程概况、结构构造、施工方法。并采用有限元模型的方法对桥梁进行结构计算,比较了不同边跨长度对桥梁刚度、支反力的影响。结果表明:桥梁各项指标满足规范要求,中跨88m范围内采用钢-混组合梁,降低了结构自重,提高了跨越能力,有利于解决传统预应力混凝土连续梁跨中下挠严重的问题。混合连续梁减少了边跨长度,提高了桥梁刚度。为满足较小的边中跨比,在边支点处配有压重段以消除支座负反力。组合梁采用分离双槽型钢梁,便于运输。采用悬拼法施工钢混组合梁,极大的缩短了工期,提高了经济性。

The(78.18+176+78.18)m hybrid continuous beam is used to cross the Huanghualaofu River in the Hefei to Wuhan section of a high-speed railway.This paper introduces the general situation,structure and construction method of the bridge.The finite element model is used to calculate the structure of the bridge,and the effects of different side span lengths on the stiffness and support reaction of the bridge are compared.The results show that the various indexes of the bridge meet the requirements of the specifications,and the steel-concrete composite beam is adopted within the range of 88m of the midspan,which reduces the dead weight of the structure,improves the crossing capacity,and is conducive to solving the serious problem of the midspan deflection of the traditional prestressed concrete continuous beam.The hybrid continuous beam reduces the length of side span and improves the rigidity of the bridge.In order to meet the smaller side to mid-span ratio,the side fulcrum is equipped with a ballast section to eliminate the negative reaction of the support.The composite beam adopts separated double-channel steel beam,which is convenient for transportation.The construction of steel-concrete composite beams by using the cantilever method has greatly shortened the construction period and improved the economy.