混合梁斜拉桥主梁钢-混凝土结合段受力性能研究

Study on the mechanical performance of the main girder’s steel-concrete joint section of a hybrid girder cable-stayed bridge

以某混合梁斜拉桥为工程背景,分别采用Midas Civil和ANSYS建立全桥空间杆系有限元模型和钢混凝土结合段的精细实体有限元模型,进行最不利荷载组合作用下结构受力性能分析。研究表明:钢-混凝土结合段在最不利荷载组合工况下各组成部分受力均衡、变形连续协调;钢-混凝土结合段的钢箱梁应力满足要求,各钢板无屈曲现象发生;钢-混凝土结合段中混凝土箱梁节段在混凝土顶板与隔板结合部及翼缘倒角位置会出现较大的主拉应力,最大可达到4.84 MPa,超过C50混凝土抗拉强度,建议必要时应增加钢筋用量,进一步优化局部受力。

With a hybrid girder cable-stayed bridge as the engineering background, Midas Civil and ANSYS were used to establish the finite element model of the space bar system of the whole bridge and that of the fine solid model of the steel-concrete joint section, and the mechanical performance under the most unfavorable load combination was analyzed. Results show that under the most unfavorable load combination, the steel-concrete joint section had the stress of all its parts balanced and the deformation continuously coordinated. The stress of its steel box girder met the requirements of the specifications, and none of the steel plates had any buckling. In the joint of the concrete roof and the partition and the flange chamfering position, the main tensile stress of the concrete could reach a maximum of 4.84 MPa, exceeding the tensile strength of concrete C50. It is suggested that more steel bars should be used when necessary to further optimize the local force.