高速铁路跨度40m与32m简支箱梁建造技术对比研究

为了对高速铁路跨度40 m和32 m简支箱梁建造技术进行对比分析,分别建立5跨40 m和32 m简支箱梁计算模型,从结构动力特性、车桥耦合动力响应两个方面,对两个计算模型进行对比研究,最后以一项工程实例为背景,从经济性角度对40 m和32 m简支箱梁方案进行对比。结果表明:对于5跨40 m和32 m简支梁计算模型,40 m简支梁模型的自振频率偏低,而梁体横向加速度和梁体位移比32 m简支梁模型偏大;墩高变化对两个计算模型的梁体横向加速度和横向位移的影响规律保持一致;对于25 m左右墩高的桥梁,采用40 m简支梁进行方案设计时,工程总造价比32 m简支梁方案偏低1.2%,并且下部工程造价明显低于32 m简支梁方案,墩高越高,这一优势越明显。

Comparative Study on Construction Technology of Simply Supported Box Girders of 40 m and 32 m Spans for High-Speed Railway

In order to compare the construction technology of simply supported box beams(SSBB) of 40 m and 32 m spans for high speed railway,the calculation models of SSBG of five spans of 40 m and32 m are set up respectively.The two calculation models are compared and analyzed from the two aspects of structural dynamic characteristics and vehicle/bridge coupling dynamic response.Finally,an engineering project is taken as the background to study the 40 m and 32 m SSBB schemes from the economic point of view.The results show that for the SSBB calculation model of five 40 m and 32 m spans,the self-vibration frequency of the 40 m SSBB is lower.The transverse acceleration and the displacement of the beam body of the 40 m beam model are larger than those of the 32 m beam model.The influence of pier height variation onthe lateral acceleration and lateral displacement of the two models is consistent.For the bridge with 25 m high piers,the total cost of the project with 40 m SSBB is 1.2% lower than that with 32 m SSBB and the cost of the substructure project is also obviously lower than that of the 32 m SSBB,and the higher the pier,the more obvious its advantage.