预制桥面板齿槽-U筋湿接缝受力机理分析

Analysis on Load Transfer Mechanism of Tooth-U Bar Wet Joint

为改善装配式桥梁预制桥面系连接性能,提升施工效率,提出一种新型齿槽-U筋湿接缝构造。通过非线性有限元模型,从混凝土应变、结合面接触应力、U筋应力等方面分析了其受力机理,并对抗弯性能影响因素开展了参数化研究。结果表明:新型湿接缝弯曲破坏过程中,依次发生预制板齿槽根部混凝土开裂、结合面渐进损伤脱黏、U筋受拉屈服,最终因顶部混凝土压溃导致结构失效。模型存在明显的弹性段、弹塑性段和屈服段。所提出的湿接缝构造U筋传力可靠,极限荷载时已发生屈服。有齿槽模型开裂荷载较无齿槽模型提高30.1%。湿接缝模型抗弯承载力受U筋直径、桥面板厚度影响较大。湿接缝长度对裂后刚度与延性存在影响。

This paper proposes a novel tooth-U bar wet joint(TUWJ)to improve the connection performance and construction efficiency of a prefabricated bridge deck.The load transfer mechanism was analyzed in detail through nonlinear finite element models in terms of concrete strain,interfacial contact stress,U bar stress,etc.a Parametric investigation of the critical factors of flexural performance was further conducted.The results indicated that the failure process of the TUWJ experiences concrete cracking at the root of the tooth,progressive degradation of the interface,yielding of U bar,and eventual concrete crushing.The evolution of load-deflection behavior could be separated into three phases,namely the elastic,elastic-plastic,and yielding phases.The yielding of the U bar at the ultimate load demonstrated that reliable force transfer was achieved by the proposed joint.Compared to the model without teeth,the model with teeth showed a 30.1%increase in cracking load.Furthermore,the diameter of the U bar and the thickness of the bridge deck were found to significantly affect the flexural strength of TUWJ,while the joint length mainly affected the post-cracking stiffness and the ductility of TUWJ.