PBL和PZ组合销剪力连接件承载力试验研究

Experimental Study on Bearing Capacity of Shear Connector for PBL and PZ Composite Dowels

为了研究剪力连接件在波形钢组合桥面板中的抗剪承载力性能,给钢混组合结构的设计提够参考,采用了推出试验方法,考虑了贯穿钢筋、椭圆孔、黏结摩擦力等影响因素,设计并制作了8组试件,得出了荷载-滑移曲线,分析了两类剪力连接件的承载力、滑移量、抗剪刚度、延性系数等静力性能指标。考虑组合销本身及椭圆孔的作用,提出了应用在波形钢组合桥面板中带椭圆开孔的PZ剪力连接件承载力计算公式。结果表明:两类剪力连接件均为混凝土剪切破坏,破坏时出现贯通裂缝,PZ连接件钢销及椭圆孔和PBL(开孔板)连接件圆孔均未发生明显变形,但贯穿钢筋变形明显。两类剪力连接件有着相同趋势的荷载-滑移曲线,相同条件下PZ剪力连接件的极限承载力高于PBL剪力连接件,而且开椭圆孔会明显提高PZ剪力连接件的极限承载力。钢板与混凝土之间的黏结摩擦力对剪力连接件的抗剪性能发挥着重要的作用。PZ剪力连接件的抗剪刚度高于PBL剪力连接件,贯穿钢筋会提高抗剪刚度,但开椭圆孔会使抗剪刚度降低。两类剪力连接件均为延性破坏,但PZ剪力连接件延性优于PBL剪力连接件。钢销下部应变幅变化较大,为PZ组合销剪力连接件应力集中区域。提出的带椭圆开孔的PZ剪力连接件承载力公式与试验结果吻合度较好。

In order to study the shear bearing capacity of shear connector in corrugated steel composite bridge deck and provide reference for the design of steel-concrete composite structure,by using push-out test method and considering the influencing factors such as penetrating reinforcement,elliptical holes and bonding friction forces,8 groups of specimens are designed and produced,the load-slip curves are obtained,and the static performance indicators of 2 types of shear connectors such as bearing capacity,slip amount,shear stiffness,ductility coefficient are analyzed.Considering the roles of the composite pin itself and the elliptical hole,the formula for calculating the bearing capacity of the PZ shear connector with elliptical openings in the corrugated steel composite bridge deck is proposed.The result shows that(1)both types of shear connectors show concrete shear failure,and penetrating cracks appeared during the failure,the steel pins and elliptical holes of the PZ connectors and the round holes of the PBL connectors are not significantly deformed,but the penetrating steel bars are deformed significantly;(2)the load-slip curves of the 2 types of shear connectors have the same trend,the ultimate bearing capacity of PZ shear connectors is higher than that of PBL(perforated plate)shear connector under the same condition,and elliptical hole can significantly improve the ultimate bearing capacity of PZ shear connector;(3)the bonding friction between steel plate and concrete plays an important role in the shear performance of the shear connector;(4)the shear stiffness of PZ shear connector is higher than that of PBL shear connector,the penetrating reinforcement can improve the shear stiffness,but the elliptical hole will reduce the shear stiffness;(5)both types of shear connectors are ductile failure,but the ductility of PZ shear connector is better than that of PBL shear connector;(6)the strain amplitude at the lower part of the steel pin changed greatly,which is the stress concentration area of PZ combining pin shear connector;(7)the proposed formula for calculating the bearing capacity of PZ shear connector with elliptical holes is in good agreement with the test result.