不同剪力连接度下装配式钢-混组合箱梁受力性能试验研究

采用预制桥面板和集簇式栓钉连接的装配式钢-混组合梁桥,可减少现浇工序,加快施工速度。文中为研究剪力槽孔间距及剪力钉数量对组合梁共同工作程度的影响,制作4片采用不同簇钉群连接参数的钢-混组合箱梁,进行抗弯弹塑性全过程加载试验,研究剪力连接度对组合梁结构受力性能的影响。结果表明,当组合梁剪力连接度由1降低到0.65时,组合梁受弯承载力减少17%;当组合梁剪力连接度大于1时,受弯承载力基本未增加,而结构延性有所下降。在界面滑移方面,随剪力连接度增大,界面滑移量则明显减少。在破坏模式方面,剪力连接度越大,预制混凝土板的纵向劈裂及局部压溃,可能成为破坏控制条件;反之,栓钉剪断及钢梁破坏易成为结构失效控制条件。

Experimental Performance of Prefabricated Steel-Concrete Composite Box Girders under Different Degree of Shear Connection

Box-girder composite bridges connected by clustered stud connectors can accelerate bridge construction and reduce the cast-in-place workload.In order to investigate the influence of degree of shear connection and number of stud connectors on the performance of composite bridge,four composite box girder specimens connected by clustered studs with different parameters were designed and fabricated.The influence of shear connection degree on the mechanical properties of composite beam structure was studied by the full process loading test of elastic-plastic bending capacity.Results of four-point loading test have shown that when the degree decreased from 1 to 0.65,the ultimate bending capacity was reduced by 17%.For composite girder with a degree of shear connection greater than unit,the ultimate bending capacity did not increase,while the ductility of the beam would be reduced.In terms of interface slip,as the degree of shear connection increased,the interface slip significantly decreased.In terms of failure mode,as the degree of shear connection became larger,the longitudinal splitting and local crushing of precast concrete slabs might become critical.Otherwise,shear rupture of stud connectors or failure of steel beam was liable to suffer structure damage.