钢筋混凝土整体式空心板桥的开裂机理和性能评估方法

Crack Mechanism and Performance Evaluation Method of Monolithic Reinforced Concrete Hollow Slab Bridge

研究了整体式空心板桥在服役过程中的裂缝和性能评估方法。通过ANSYS软件建立精细空间实体模型,分析了设计荷载作用下整体式空心板桥开裂的机理;在弹性分析的基础上,考虑材料非线性的影响,对荷载试验的结果进行评估,并与刚接板法和弹性有限元分析结果进行比较;引入钢筋的锈蚀模型,对整体式空心板的时变极限承载力进行分析。研究结果表明:车辆偏载引起的横向挠曲是桥梁纵向开裂的主要原因,建议对整体式空心板桥进行评估时应同时考虑材料非线性和钢筋锈蚀的影响。

Crack mechanism of reinforced concrete hollow slab bridge and its performance evaluation method are studied.A refined spatial solid model is established by ANSYS to investigate the crack mechanism of bridge under design loads.And then on the basis of the elastic analysis,the load test results are evaluated,with the consideration of the nonlinear performance of concrete material.The load test results are compared with the results got by rigid-connection slab and elastic linear finite method.The corrosion model of steel bar is introduced for the long term performance evaluation,and the time-dependent carrying capacity of the bridge is analyzed.The study results indicate that the horizontal deflection caused by the vehicles＇ eccentric load is the main cause of the longitudinal cracking of bridge.It is suggested that the nonlinear performance and corrosion should be included in the evaluation of hollow slab bridge.