既有双链柔式钢索悬索桥承载力评估

Load Bearing Capacity Evaluation of Existing Suspension Bridges with Double Flexible Cables

通过实桥病害调查及静动载试验,结合有限元模型,提出了考虑疲劳及钢材锈蚀影响的承载能力系数进行既有悬索桥承载力评估的方法,并应用该方法对某双链柔式钢索悬索桥的承载力进行了评估。结果表明,该悬索桥在当前状态下能够满足安全性要求,加劲梁不需要进行加固,但主缆及桥面已发生变形,需对悬吊系统进行校正;索塔顶水平位移过大,应予以加固。此类评估为既有悬索桥的养护、维修和技术改造提供了科学依据。

Through defect investigation and static and dynamic load tests of real bridges and in combination with the finite element analysis （FEA）, a method for evaluating the load bearing capacities of existing suspension bridges by means of the coefficients of load bearing capacities is proposed. The coefficients take into consideration fatigue and steel rust. The method is applied in evaluation of a double flexible cable suspension bridge. It is demonstrated that the bridge is able to satisfy the safety requirements under the present conditions and the stiffening girder does not need any reinforcement. However, the suspension system needs to be rectified due to deformation of the main cable and decks the displacement of the cable tower top is so large that it should be strengthened. The evaluation provides scientific foundations for maintenance, rehabilitation and technical reconstruction of existing suspension bridges.