中国铁道科学2025，Vol.46Issue(5)：138-148,11.DOI:10.3969/j.issn.1001-4632.2025.05.12
公铁两用斜拉桥钢混板-桁组合梁钢-混结合段受力特性
Stress Characteristics of Steel-Concrete Joint in Steel Truss-Concrete Slab Composite Girder of a Cable-Stayed Combined Highway and Railway Bridge
摘要
Abstract
To investigate the mechanical characteristics of steel-concrete joints in a long-span cable-stayed railway-highway hybrid bridge with novel steel truss-concrete slab composite girders,this study employed the 808 m main-span Hongqili Grand Bridge as a prototype.Through nested finite element simulations integrating global truss modeling and local spatial solid modeling of composite joints,comprehensive analyses were conducted on the structure stress,longitudinal-transverse stress distribution laws,and load transfer mechanisms of upper and lower deck steel-concrete joints.The results demonstrate that under the most unfavorable working condition of the main and additional load combination,the bearing plates of the upper and lower steel-concrete composite joint and the lower chords of the main truss exhibit the most critical stress states,and the local most unfavorable stress of the steel structure reaches 280 MPa.The concrete components display a maximum tensile stress of 4.5 MPa,indicating insignificant tensile behavior compared with the C60 steel fiber concrete.The maximum flexural angles of highway and railway deck composite joints are measured as 0.93×10-3 rad and 1.09×10-3 rad,respectively,both complying with code-specified stiffness requirements.Distinct stress discontinuities observed in steel top/bottom plates near bearing plates indicating that the bearing plate has obvious concentrated force transmission effect,while diaphragm plates significantly influence stress distribution patterns in railway deck.Transverse stress non-uniformity coefficients reach peak values of 1.4 and 2.7 for steel plates and concrete in upper and lower composite joints respectively,indicating significant nonuniformity.The paths with"uneven"stress distribution in the concrete of composite joints account for 33.3%,which is higher than the proportion(16.7%)of the steel plates,and have more obvious unevenness.The steel plates of the upper and lower composite joints mainly transfer the force through shear studs,transmitting 47.4%and 64.5%of the axial force respectively.The direct application of the bearing plates also serve as an crucial load-transfer path.The longitudinal distribution curve of the structural load-transfer ratio exhibits a smooth gradient,indicating efficient and uniform load transfer.关键词
公铁两用斜拉桥/钢混板-桁组合梁/钢-混结合段/受力特性/应力分布/传力机理/仿真分析Key words
Cable-stayed combined highway and railway bridge/Steel truss-concrete plate composite girder/Steel-concrete joint/Mechanical characteristics/Stress distribution/Force transfer mechanism/Simulation analysis分类
交通运输引用本文复制引用
施洲,李嘉辉,李英铭,姜家琛,刘振标,夏正春..公铁两用斜拉桥钢混板-桁组合梁钢-混结合段受力特性[J].中国铁道科学,2025,46(5):138-148,11.基金项目
中国国家铁路集团有限公司科技研究开发计划课题(N2021G034) （N2021G034）
