新型焊接抗剪连接件试验研究与实桥计算分析

Experimental Research and Bridge Numerical Study of A New Type of Welded Shear Connector

采用静力推出试验,研究钢与UHPC(Ultra-high Performance Concrete)间新型钢筋网局部焊接抗剪连接件的静力性能。通过4个不同界面处理(有无界面粘结)的静力推出试验,测得焊接抗剪件的荷载-滑移曲线和抗剪承载力,试验结果表明焊接抗剪件极限承载力高,单个焊接抗剪件的抗剪承载力平均值达99.25 kN;钢-UHPC界面粘结对抗剪承载力无显著影响;以某大桥为工程背景,初步研究不同连接件布置方式对焊接抗剪件受力性能影响。计算结果表明随着布置间距增大,焊接抗剪件承担剪力增加,但剪力峰值仍处于较低水平;采用300 mm×400 mm(横桥向×纵桥向)焊接抗剪连接件的布置方式可满足界面静力与疲劳抗剪设计要求。

In order to study the static performance of an innovative welded rebar mesh shear connector used in the composite deck system of steel and thin UHPC(ultra-high performance concrete),static push-out tests were carried out.Through testing 4 push-out specimens with different interface adhesion(with or without interface bonding),the load-slip curves and shearing bearing capacities of shear connectors were obtained.The experimental results indicate that the ultimate bearing capacity of welded shear connectors is high and the average value of shearing capacity of single welded shear connector is 99.25 kN;The interfacial bonding of steel-UHPC has no influence on the shearing bearing capacity of specimens;Taking a certain large-scaled bridge as an engineering background,the influence of different arrangement methods on the mechanical properties of the welded shear connectors is preliminarily studied.The numerical results show that with the increase of the spacing of the layout,the shear force of the welded shear connectors grows.However,the peak shear force remains in a relatively low level;The arrangement of connectors,which is 300 mm×400 mm(transverse×longitudinal),can meet the interfacial static and fatigue shear-resistant design requirements under vehicle loads.