铁道科学与工程学报2024，Vol.21Issue(7)：2778-2789,12.DOI:10.19713/j.cnki.43-1423/u.T20231633
公铁合建斜拉桥钢桁-混凝土板组合梁受力特性
Mechanical characteristics of steel truss-concrete slab composite girder of a railway-cum-road cable-stayed bridge
摘要
Abstract
Taking the rail-cum-road new type steel truss-concrete slab composite girder cable-stayed bridge with a main span of 808 m,Hongqili Grand Bridge,as the background,the multi-scale whole bridge finite element model with fine local composite girder segments was established using ANSYS software.The mechanical properties,force transmission characteristics and load distribution ratio of the double-layer composite girder under different working conditions were analyzed.The influence of the thickness of the concrete bridge deck tb,the stiffness variation coefficient of the crossbeam λK and the elastic modulus ratio of steel and concrete λE on the stress of the composite girder was discussed.The results show that the most unfavorable Von Mises stress of steel truss is 183.6 MPa and the maximum tensile stress of concrete deck is 5.3 MPa under the most unfavorable working condition.The results can meet the requirements of structural force.Along the longitudinal path,the stresses of steel truss and concrete both wave between the inter-section crossbeams.The stresses on the top and bottom surfaces of both upper and lower concrete decks approximately illustrate the‘W'and‘M'shapes along the transverse direction,indicating that the concrete decks bear a certain un-uniform bending moment along the transverse direction.The maximum shear lag coefficients of highway and railway concrete decks are 1.45 and 1.36,respectively.The shear lag effect of wider highway concrete decks is more significant.The concrete decks of highway and railway bear 57.46%～79.99%and 33.21%～62.81%axial loads of the upper and lower structures respectively,which are the main force transfer components of the composite girder.The stress of the concrete deck increases with the increase of tb and λK and decreases with the increase of λE.The average load distribution ratio ξ of each layer of the concrete deck is proportional to tb,and inversely proportional to λK and λE.When the parameters of tb,λK and λE are in the range of 0.8～1.4,0.4～1.6 and 4～10,respectively,the stress and load distribution ratio of the main girder concrete deck are reasonable.关键词
大跨度公铁合建斜拉桥/钢桁-混凝土板组合梁/受力特性/传力特性/参数分析Key words
long-span rail-cum-road cable-stayed bridge/steel truss-concrete slab composite girder/stress characteristic/force transmission characteristics/parametric analysis分类
建筑与水利引用本文复制引用
施洲,赵旭泼,刘振标,夏正春,印涛..公铁合建斜拉桥钢桁-混凝土板组合梁受力特性[J].铁道科学与工程学报,2024,21(7):2778-2789,12.基金项目
国铁集团科技研发项目(N2021G034) （N2021G034）
中铁第四勘察设计院集团有限公司科技研发项目(2021K015) （2021K015）
