大跨径钢箱梁斜拉桥静载试验研究

Static Load Test of Long-span Cable-stayed Bridge with Steel-box Girder

以象山港大桥斜拉桥为背景,通过实桥荷载试验分析,研究斜拉桥在静力荷载作用下结构的应力水平和变形。研究表明,在相当于设计汽车荷载水平的试验荷载作用下,大桥结构处于线弹性工作状态,变形增量与荷载增量呈线性关系;结构总体变形、应力、索力的理论值与实测结果较为接近;钢箱梁应力水平较低,受剪力滞效应、横坡及车轮局部效应等影响,钢箱梁顶、底板应力沿横截面呈纵向不均匀分布,尤其顶板U肋出现集中现象,这在桥梁健康监测中值得关注。

The paper presents a numerical analysis of the styesslevel、deflkection and distribution of Xiangshangang Bridge of China on the basis of the field static load tests.The results show that the bridge under the planned load test conditions is of good overall static properties and linear superposition characteristics,and incremented deflection is observed to be linearly proportional to incremental load.A good agreement is achieved between the experiential and analytical results such as displacements,stresses and cable forces.The stress level of the steel-box girder under static loads is low,the longitudinal stress distributions of the slab and floor beam are non-uniform,the reasons for these phenomena include the shear lag effect and the influence of transversal slope of steel box girder as well as local stress effect of wheel load.And the U-shape ribs are of critical importance in bridge health monitoring because of its stress concentration.