市域铁路梁式桥跨结构设计参数研究

Study on Design Parameters of Girder Bridge Span Structure in City Railway

[目的]TB 10624—2020《市域(郊)铁路设计规范》在编制的过程中,沿用了GB 50157—2013《地铁设计规范》和TB 10623—2014《城际铁路设计规范》的大部分内容。为了验证TB 10624—2020中梁式桥跨结构的挠跨比、自振频率及动力系数等设计参数制定的合理性,需对其进行深入研究。[方法]根据市域铁路与其他类型铁路在桥梁设计标准上的差异,基于车桥耦合动力仿真的理论计算,分析了市域铁路梁式桥跨结构的挠跨比、自振频率和动力系数的合理设计限值。[结果及结论]由于荷载的差异,市域铁路梁式桥跨结构挠度设计限值不宜沿用TB 10623—2014中的规定,需制定满足市域铁路自身的刚度的设计标准;提出了适合市域铁路梁式桥跨结构的自振频率设计限值;市域铁路桥梁采用TB 10002—2017《铁路桥涵设计规范》中客货混运铁路桥梁的动力系数是合理的,且有一定的安全保证。

[Objective]The compiling of TB 10624—2020 Urban(Suburban)Railway Design Code follows most of the content of GB 50157—2013 Subway Design Code and TB 10623—2014 Intercity Railway Design Code.In order to verify the reasonability of the design parameters of girder bridge span structure in TB 10624—2020,such as deflection-span ratio,natural vibration frequency and dynamic factor,further research is needed.[Method]According to the differences in bridge design codes between city railway and other types of railways,the reasonable design limits of deflection-span ratio,natural frequency and dynamic factor of city railway girder bridge span structure are analyzed on the basis of the theoretical calculation of train-bridge coupling dynamic simulation method.[Result&Conclusion]Due to the train load differences,the deflection design limits for girder bridge span structure in city railway should not follow TB 10623—2014 and the design standard that meets the rigidity requirement of city railway itself should be formulated.The natural frequency design limit applicable to the girder bridge span structure of city railway is proposed.The dynamic coefficient of city railway bridge following that of mixed passenger/freight transport railway bridge in TB 10002—2017 Code for Design of Railway Bridges and Culverts is reasonable and has certain safety guarantee.