超载作用下空心板梁铰缝疲劳损伤分析

Fatigue Damage Analysis of Transverse Joint of Hollow Slab Bridges Subject to Overloading

为了深入研究超载作用下空心板梁铰缝破损开裂病害的原因,从疲劳角度出发对横向弯曲应力及其引起的疲劳损伤进行分析。调研分析了沈海高速公路的超载运营状况及空心板梁铰缝破损开裂现象,通过对比国内外规范中的疲劳荷载模型,选用我国规范中的疲劳荷载模型Ⅱ,进行了基于ANSYS空间实体模型的横向应力计算。结果表明,车辆加载位置处铰缝横向弯曲应力大,疲劳损伤显著。通过引入超载疲劳放大因子,发现超载对空心板梁铰缝受拉疲劳十分敏感,随着荷载线性增加,其疲劳损伤效应呈超线性增加。因此,超载运输是致使空心板梁铰缝开裂破坏的一个主要因素。

In order to research the causes of the damage of the hinge seam of the hollow girder under overload,transversebending stress and its fatigue damage has been analyzed from perspective of fatigue. The research from Shenhai Highwayabout the overloading conditions and the phenomenon of cracking at transverse joint was conducted. The fatigue loadmodel 域from the highway bridge design codes of China was selected by comparing several fatigue load models of othercountries. A finite element solid model is established to calculate the transverse bending stress based on the softwareANSYS. The results showed that the bending stress at the position corresponding to the vehicle locate was obviouslylarger,which was prone to cause fatigue danmage. By introducing overloading amplification factor of fatigue,overloadingwas sensitive to the tensile fatigue damage effect of transverse joint of hollow slab bridges. With the linear increase ofload,the corresponding fatigue damage effect was superlinearly increased. Therefore,the overloading traffic is a majorfactor causing the cracking and spalling at transverse joint of hollow slab bridges.