基于PBL-栓钉组合剪力键的钢-UHPC组合桁式拱桥节点拉拔性能研究  

Research on Pull-Out Behavior of Joints with PBL-Studs Composite Shear Connectors of Steel-UHPC Composite Truss Arch Bridge

作　　者：邵旭东[1,2] 陈玉宝 何广 赵旭东 SHAO Xu-dong;CHEN Yu-bao;HE Guang;ZHAO Xu-dong(School of Civil Engineering,Hunan University,Changsha 410082,China;Key Laboratory of Wind Engineering and Bridge Engineering,Hunan University,Changsha 410082,China)

机构地区：[1]湖南大学土木工程学院,湖南长沙410082 [2]湖南大学风工程与桥梁工程湖南省重点实验室,湖南长沙410082

出　　处：《桥梁建设》2022年第1期33-40,共8页Bridge Construction

基　　金：国家重点研发计划项目(2018YFC0705406);国家自然科学基金重点项目(52038003)。

摘　　要：为研究概念设计的1000 m钢-UHPC组合桁式拱桥新结构中拱肋-腹杆节点构造形式、UHPC强度对节点拉拔性能的影响,及新型PBL-栓钉组合剪力键应用于拱肋-腹杆节点的有效性,设计制作缩尺比为1∶5的4种采用不同剪力键形式(1对PBL剪力键+2排栓钉、2对PBL剪力键+3排栓钉、2对PBL剪力键、3排栓钉)的拱肋-腹杆节点模型进行拉拔试验,并进行缩尺、足尺模型有限元分析。试验和缩尺有限元分析结果表明:采用PBL-栓钉组合剪力键、仅采用PBL剪力键、仅采用栓钉的拉拔试件的破坏模式分别为UHPC拱肋剪切破坏、锚固区UHPC拔出、栓钉拉断;采用PBL-栓钉组合剪力键的试件最大安全系数为2.43,满足设计要求。根据足尺有限元模型结果,采用PBL-栓钉组合剪力键的拱肋-腹杆节点总用钢量少,拉拔性能好,设计合理;UHPC的抗压强度对节点的拉拔性能影响不大;适当提高UHPC的抗拉强度可提高节点的拉拔极限承载力。The steel-UHPC composite truss arch bridge is of feasibility in concept design.In this paper,the PBL-studs composite shear connectors for arch rib-web member joints are proposed,the effects of patterns of arch rib-web member joints as well as the strength of UHPC on the pull-out behavior of the joints are investigated and the applicability of the PBL-studs composite shear connectors to the arch rib-web member joints are verified.The 1∶5 scale-down mockups of arch rib-web member joints with four different types of shear connectors are prepared,one with a pair of PBL connectors and two rows of studs,one with two pairs of PBL connectors and three rows of studs,one with just two pairs of PBL connectors and one with mere three rows of studs.Moreover,the scale-down and full-scale models are numerically simulated.In the tests and scale-down and full-scale finite element analysis,the specimens with PBL-studs composite shear connectors,with just PBL connectors or studs exhibit the damages of shear failure of UHPC arch rib,pull-out of UHPC in anchorage zone and break of studs,respectively.The maximum safety factor of the specimen with PBL-studs composite shear connectors is 2.43,which meets the design requirements.According to the full-scale finite element analysis,by using the PBL-studs composite shear connectors,the arch rib-web member joints exhibit excellent pull-out resistance,but consume less steel,proving the feasibility of the design idea.The compressive strength of UHPC contributes little to the pull-out resistance of the joints.However,appropriate enhancement of the tensile strength of UHPC can lead to the improvement of the ultimate pull-out resistance of the joints.

关 键 词：钢-UHPC组合桁式拱桥 拱肋-腹杆节点 PBL剪力键 栓钉 组合剪力键 拉拔试验 抗拔性能 有限元法 

分 类 号：U448.224[建筑科学—桥梁与隧道工程]