大跨度钢-混凝土组合梁桥静载试验及初应力分析  

Field Test and Initial Stress of Large-Span Steel-Concrete Composite Bridges

作　　者：王庆贺 杨永琛 刘瑞鑫 王超[1] WANG Qinghe;YANG Yongchen;LIU Ruixin;WANG Chao(School of Civil Engineering,Shenyang Jianzhu University,Shenyang,China 110168)

机构地区：[1]沈阳建筑大学土木工程学院,辽宁沈阳110168

出　　处：《沈阳建筑大学学报（自然科学版）》2022年第1期95-101,共7页Journal of Shenyang Jianzhu University：Natural Science

基　　金：国家自然科学基金项目(51808351);天津市科技计划项目(18ZXGDGX00030);辽宁省科技厅博士科研启动项目(2019-BS-193);沈阳市中青年科技人才项目(RC200143)。

摘　　要：目的研究桥梁在服役荷载下的混凝土及钢梁初始应力,评价大跨度钢-混凝土组合桥梁成桥阶段的混凝土开裂风险。方法进行桥梁成桥阶段的静载试验,实测不同工况下桥梁典型截面的挠度和应力水平;采用MIDAS/Civil软件建立钢-混凝土组合梁桥有限元模型,并采用静载试验数据验证模型的可靠性。结果桥梁各截面的应力和挠度均低于理论计算值,应力校验系数为0.78~0.82、挠度校验系数为0.55~0.91;桥梁产生一定的残余应变与残余变形,最大残余应变为1.87%,残余变形为18.0%;有限元结果与试验结果相差较小,实测值与理论值大多相差在20%以内,在设计荷载作用下,钢-混凝土组合梁的中部支座附近的混凝土将发生开裂,开裂约为桥梁跨度的16%~38%,槽型钢梁的应力水平约为屈服强度的36%。结论桥梁抗扭性能较好且实际应用状态优于设计状态,有限元模型可以较好地模拟静力荷载作用下的组合结构桥梁的应力与挠度,在正常服役荷载作用下,大跨度钢-混凝土组合桥梁中混凝土存在开裂风险,但开裂范围有限。The initial stress state on concrete component and steel component under design loads are obtained based on which the cracking possibility of concrete component is evaluated for large-span composite bridges.With this aim,static load tests were carried out to measure the deflection and stress levels of typical bridge sections under different working conditions.Midas/Civil software was used to establish the finite element model of steel-concrete composite bridge,and static load test data were used to verify the reliability of the FE model.The static load test results show that the stress and deflection of each section of the bridge are lower than the theoretical calculation values,and the stress check coefficient is 0.78~0.82,and the deflection check coefficient is 0.55~0.91.In addition,the residual strain and residual deformation of the bridge are limited,the maximum residual strain 1.87%and the residual deformation 18.0%.The difference between the finite element results and the experimental results is small,and the difference between the measured values and the theoretical values is mostly within 20%.Under the design load,the concrete near the central support of the steel-concrete composite beam will crack,the crack range about 16%~38%bridge span,and the stress level of the channel steel beam about 36%yield strength.Static load tests show that this kind of bridge has good torsional resistance and the actual application state is better than the design state.The finite element model can simulate the stress and deflection of the composite structure bridge under static load.Under the service load,the concrete in the long-span steel-concrete composite bridge has the risk of cracking,but the cracking range is limited.

关 键 词：钢-混凝土组合结构 静力荷载试验 有限元分析 初应力 

分 类 号：TU398[建筑科学—结构工程]