煌水河双曲拱桥的病害诊断与力学性能研究

以某四孔钢筋混凝土空腹式连续双曲拱桥为例,结合目前既有双曲拱桥的典型病害调研和国内外旧桥承载力的评定方法,对其进行了全面的健康检测,根据现场拱肋线形的实测结果,建立了该桥原设计与现行状态的全三维有限元分析模型,从理论上分析了该桥产生病害的主要原因,理论分析结果得到了现场调研数据的验证。得到了桥梁长期单方向超载以及拱肋横向联系弱、横向分布效应差,造成一侧拱肋应力长期处于高水平而产生徐变变形,主拱肋偏离原悬链线拱改变了其主要承压设计思想,加之年久失修造成恶性循环,从而成为“危桥”的结论,为该桥的加固设计提供了科学依据。

Disease Diagnosis and Mechanical Performance Study of Double-curve Arch Bridge on Huangshui River

Taking one 4-span steel reinforced concrete open spandrel double-curve arch bridge as an example, and combined with the investigation and study of the typical disease of the double-curve arch bridge at present and the evaluation method of the old bridge bearing capacity at home and abroad, the overall health examination is carried out for the bridge. Based on the measured result of the arch rib alignment in the field, the full three-dimensional finite element analysis model of the original design and the present status for this bridge is set up. The article theoretically analyzes the main reasons of causing disease in the bridge. The theoretical analysis result has been verified by the field investigation and study data. The conclusion has been obtained that one-way overload of the bridge for a long time, weak transverse connection of the arch rib and bad effect of the transverse distribution cause the arch rib stress at one side being placed at the high level for a long time so as to create the creep deformation, the main bearing design idea of the arch has been changed because of the main arch rib departing from the original catenary plus vicious circle by having long been out of repair so as to cause the "danger bridge". The above provides the scientific basis for the design to reinforce the bridge.