混合桥面横向连接构造静力性能

Static Performance of Transverse Connection Detail of Hybrid Deck

将大跨度桥梁外侧车道及车道以外部分桥面的正交异性钢板替换为超高性能混凝土(UHPC)华夫板而形成混合桥面系统,提出连接2种桥面的横向连接构造。对横向连接构造进行静力弯曲试验和理论分析,得到正、负弯矩作用下的破坏模式、极限承载力、抗裂性能、两侧桥面的协同受弯性能。最后,给出了考虑UHPC开裂后残余应力的断面塑性极限承载力计算方法。结果表明:该横向连接构造有较好的塑性变形能力并协同两侧桥面共同受力,弹性阶段横向连接构造两侧的正交异性钢板和UHPC华夫板断面应变符合平截面假定。由提出的断面承载力理论计算方法预测的正弯矩作用试件极限承载力误差在8%以内,负弯矩作用试件承载力由板件局部屈曲控制,断面承载力理论计算方法须考虑局部稳定的影响。

By substituting the orthotropic steel desk(OSD)of nearside lane and emergency lane with a ultrahigh performance concrete(UHPC)waffle deck for a large-span bridge,a hybrid deck system was formed.Thus,a transverse connection detail to link the two types of decks was proposed.Specifically,positive and negative bending specimens of the transverse connection detail were designed and tested to determine the failure mode,ultimate bearing capacity,anti-cracking performance,and cooperative moment bearing performance.Lastly,a method of calculating the bearing capacity after cracking was presented by taking into account the residual stress of UHPC.The bridge decks on both sides are able to cooperate with each other in bearing the external load through the transverse connection detail,indicating better plastic deformation capability.The OSD and UHPC waffle decks conform to the plane section assumption in elastic stage.With the proposed bearing capacity calculation method,the bearing capacity of the positive bending specimen can be predicted with satisfactory accuracy and the error is within 8%.Local buckling is an important factor in determining the ultimate bearing capacity of the negative bending specimen,which should be considered when calculating the bearing capacity.