ABSTRACT
Group studs shear connectors is an important part of rapid construction steel-concrete composite bridge. Because of the spacing between every stud and stud in the group studs is too small under action of load, the stress interaction and overlapping influence among studs and the concrete makes the average shear bearing capacity and shear stiffness of every stud in group studs be lower than the calculated values of single stud. In this paper, aiming at the rapid construction steel-concrete composite small box girder and taking the diameter, depth of the studs, transverse and longitudinal spacing between the studs, number of the studs in the group studs and concrete strength grades as parameters, 22 push-out specimens with different stud group were analyzed by the finite element method. It was found that “stud group effect” could not be ignored. On this basis, according to analysis of the concrete stress distribution and mode in the arrangement of typical group studs, assuming the concrete stress to diffuse and transfer in the internal friction angle of concrete, the simplified calculation model for analyzing the “stud group effect” of the typical steel and concrete composite small box girder was proposed. The quantitative analysis of the proposed method and FEM and the comparison of their results were carried on, it shown there is in good agreement, the maximum error is among 11.4%.
