大跨径简支双层桥面复合桁梁桥钢-混凝土节点试验研究

Experimental Study on Steel-concrete Joint of Large Span Simple-support Double-deck Composite Truss Bridge

双层复合桁梁桥钢-混凝土节点体积大、钢筋密、空间小,构造复杂,是纵横向预应力索的交汇点,也是受力的关键点。为更好地指导施工,在施工前,采用1∶1的比例模拟实桥结构钢-混凝土结合节点的纤维混凝土浇筑试验,待节点混凝土达到强度后,对节点进行切割。通过对节点纤维混凝土的密实度和钢与混凝土的结合度进行检查,结果表明节点混凝土密实度较好,钢与混凝土结合密贴。可为后续实桥的施工提供经验和参考,使之达到国家相关质量规范要求。

The steel-concrete joint of the double-deck composite truss bridge has the characteristics of large volume,dense concrete,small space and complicated structure. It＇s a key pressure point and an intersection of vertical and horizontal prestressed cable. Fiber concrete pouring test of the joint was performed by simulation of bridge structure,and the component was cut at a certain strength level. The compactness of fiber reinforced concrete and the connection between steel and concrete were analyzed. The results show the concrete compactness was increased to a great extent and the steel-concrete connection was enhanced. The experiment provides instruction and guidance for the construction of real bridge to meet its national unified quality standard.