空心板梁桥整体化层厚度对受弯失效模式的影响

Influence of the Integral Layer Thickness on the Failure Mode of the Hollow Slab Beam Bridges

目前中小跨径桥梁中装配式空心板梁结构应用广泛。随着长期服役过程中车辆荷载等条件的变化,现役空心板梁结构产生了纵向开裂等桥梁损伤和病害问题。当下旧桥加固和改扩建工程中,整体化层厚度调整能够便捷高效地提升结构叠合共同工作性能和承载能力,但也存在失效模式转变的风险。本研究针对装配式空心板梁桥关键构造失效模式,考虑不同整体化层厚度影响,开展铰缝受弯性能足尺试验研究。基于铰缝模型破坏模式、荷载—挠曲关系以及关键荷载指标开展对比研究,对整体化层厚度参数进行优化,为后续装配式空心板梁设计以及在役结构改扩建提供参考。

Fabricated hollow slab beams are widely used in medium and small-span bridges at present.With the change of service condition like the vehicle load,the damage and defects problems like the longitudinal crack occur on the in-service hollow slab beam bridges.In the current maintenance and expansion projects of old bridges,the thickness adjustment of integral layer can improve the serving performance and the bearing capability with the structural composite effect,but there is also the risk of unexpected failure mode.Herein,in this study,aiming at the failure mode of the critical components in fabricated hollow slab beam bridges,the full-scale experimental study on the flexural performance on the hinge joint are conducted,considering the different thickness of the integral layer.Based on the comparative analysis on failure mode,load flexural relation and critical load of hinge joint model,the thickness of integrated layer is optimized through this study,and provides reference for the design of following fabricated hollow slab beams and the reconstruction projects on in-service structures.