基于损伤模型的聚碳酸酯板桥异常裂缝成因分析及处置

预应力钢筋混凝土简支板桥由于自身结构简单、便于施工、较强的适应性以及较为经济等优点,如今仍被用作桥梁首选的桥型设计之一。但其也存在一些不足之处,许多桥梁在通车不久就相继出现不同的病害,其中梁板横向裂缝与纵向裂缝病害较为常见,将会对桥梁结构的安全性及耐久性产生较大影响。以一个先张法预应力混凝土空心板桥梁作为依托工程,分析了该桥梁端异常横缝产生的原因,通过有限元分析软件ABAQUS建立单梁的1/4模型进行分析,探讨预应力空心板梁在超载及预应力逐渐损失的情况下,对梁端产生横向裂缝的影响。结果表明:随着荷载的增大和预应力的不断损失,梁端附近混凝土损伤较为严重,且应力应变最先达到最大,先于其他部位出现开裂。在此基础上,通过TRM加固方法对损伤梁进行加固处理,整体承载能力显著提高,破坏形态明显改善。

Cause Analysis and Treatment of Abnormal Cracks in PC Slab Bridge Based on Damage Model

Prestressed reinforced concrete simple supported slab bridge is still used as one of the preferred bridge type designs because of its simple structure, easy construction, strong adaptability and relatively economic advantages. But there are also some shortcomings. Many bridges have different diseases shortly after opening to traffic. The transverse and longitudinal cracks of beam and slab are more common, which will have a greater impact on the safety and durability of bridge structures. Based on a pre-tensioned prestressed concrete hollow slab bridge, this paper analyses the causes of the abnormal transverse joints at the end of the bridge. Through the finite element analysis software ABAQUS, a 1/4 model of a single beam is established to analyze the effect of the transverse cracks at the end of the beam under overload and progressive loss of prestress. The results show that with the increase of load and the continuous loss of prestressing force, the damage of concrete near the end of beam is more serious, and the stress and strain reach the maximum first, and crack occurs before other parts. On this basis, TRM reinforcement method is used to reinforce damaged beams. The overall bearing capacity and failure mode of damaged beams are improved significantly.