正交异性钢板-薄层RPC组合桥面基本性能研究

Research on Basic Performance of Composite Bridge Deck System with Orthotropic Steel Deck and Thin RPC Layer

为了解决正交异性钢桥面铺装层破损及钢桥面结构疲劳开裂2类病害问题,提出了一种新型正交异性钢板-薄层超高性能活性粉末混凝土(RPC)组合桥面结构体系。基于某大桥建立有限元模型,并对比计算了纯钢梁和组合桥面结构中桥梁主缆索力和桥面系应力状态;同时,开展了足尺条带模型静载试验。研究结果表明:采用新型钢-RPC组合桥面结构后,钢面板及纵肋中应力明显降低且最大降幅超过70%,而主缆索力几乎不增加;RPC层开裂前的拉应力可达42.7MPa,远高于其在实桥荷载作用下10.08MPa的拉应力;该新型钢-RPC组合桥面结构可提高桥面系的刚度,降低钢桥面结构中的应力,从而能够基本消除钢桥面疲劳开裂的风险。

In order to deal with the problems of damage in orthotropic steel deck and fatigue crack in steel deck structure,an innovative composite bridge deck system with orthotropic steel plate and thin reactive powder concrete（RPC） layer was presented.Finite element models were established on the basis of a certain bridge.Pure steel girder and composite girder were created respectively to compute tension force in the main cable and stress state in bridge deck system.Then,static load experiment of full-scale composite beam model was carried out.The results show that tensile stresses in steel deck decrease obviously when the innovative steel-RPC composite deck system is adopted and the maximal reducing amplitude is over 70%.But the tensile force in main cable can hardly increase.Tensile stress of the RPC layer is up to 42.7 MPa before tiny cracks appear,which is much greater than 10.08 MPa in calculation.Stiffness of original orthotropic steel deck can be improved by the composite bridge deck system.Consequently,stress in orthotropic steel deck decreases greatly,which will effectively eliminate the risk of fatigue cracking in steel deck.