基于荷载试验及有限元分析的斜拉杆钢箱梁式人行天桥的安全性研究

Study on safety of tension-diagonal pedestrian bridge with steel box girder based on the load test and the finite element analysis

采用荷载试验结合有限元分析的方法是一种重要的桥梁安全性评估手段。以实际工程为背景,对一种采用较少的斜拉杆钢箱梁式人行天桥进行了荷载试验及有限元分析。首先通过理论分析和有限元模拟,确定了现场静载试验的加载工况、加载与卸载的过程与量级以及主控制截面和截面中的测点空间位置分布。在试验荷载作用下测定人行天桥控制截面的应力、挠度或位移值,并将测试结果与有限元分析结果进行对比,以验证是否符合规范与设计要求。最后综合评估了该人行天桥的安全性能,为维修加固和后续使用维护提供依据。

Method that combining the load test with the finite element analysis is important to evaluate the safety of bridges. An actual project is taken as the background; moreover the load test and finite element analysis are used to a tension- diagonal pedestrian bridge which girder is steel box. Firstly,the loading conditions,loading and unloading process and the magnitude,as well as the main control section and the spatial distribution of the measuring point in the cross section are determined through theoretical analysis and finite element simulation in the static load test. After the stress and deflection or displacement are measured and recorded when the pedestrian bridge is in the test loads,the measured values are compared with the theoretical values to verify if the structure satisfy the specifications and design requirements. Finally,the safety performance of the pedestrian bridge is comprehensively assessed. Furthermore,the basis for repair,reinforcement and the following maintenance are provided.