中文摘要：

为了研究快速施工钢-混组合结构中群钉剪力连接件在复杂应力条件下的受力特性,探讨焊钉尺寸和不同应力条件对群钉推出试件受力特性的影响,基于混凝土和焊钉损伤塑性模型,考虑结构非线性行为,采用数值有限元法对设计的5组不同参数的群钉推出试件进行数值模拟及分析。在此基础上,进一步分析了不同横弯力和预压应力对焊钉周围的混凝土性能和焊钉失效模式的影响。结果表明：横弯力和预压应力对焊钉的滑移影响较小,但对焊钉的抗剪承载能力和抗剪刚度影响较大;增大横弯力和预压应力,焊钉的抗剪承载力最多可提高31%,抗剪刚度最多可提高61%;焊钉高度大于其直径的4倍时,其高度变化对群钉中焊钉的平均抗剪承载能力和抗剪刚度影响不大;基于混凝土和焊钉损伤塑性模型的有限元建模方法可以较好地用于钢-混组合结构群钉力学行为的参数分析;横向预应力的施加,能够有效改善群钉周围混凝土的性能,提高群钉剪力连接件的刚度和钢-混组合结构耐久性,为群钉在快速施工钢-混组合结构桥梁中的应用提供新的技术选择。

英文摘要：

In order to investigate mechanical characteristics of group studs in accelerated steelconcrete composite structures under complicated stress condition,and explore the influence of different stud sizes and stress conditions on grouped push-out specimens,the push-out simulation of five kinds of grouped studs with different parameters was conducted by finite element method（FEM）taken the nonlinear behavior of the composite structure into account,in terms of the damaged plasticity model of the concrete and stud.What＇s more,the effects of different lateral bending forces and prestressing on the failure mode of studs and the surrounding concrete were further analyzed.The results show the lateral bending forces and prestressing have a greaterinfluence on the shear capacity and shear stiffness,but less influence on slip of studs.With the increase of lateral bending forces and prestressing,the shear capacity and shear stiffness increases by 31% and 61% respectively at most.The effect of height changes on the shear capacity and shear stiffness is slight when the stud height is 4times greater than the stud diameter.Moreover,the proposed finite element simulate method based on damaged plasticity model is preferably used for the parametrical analysis of group studs in the steel-concrete composite structures.The application of lateral prestressing improves the performance of surrounding concrete obviously and enhances the shear stiffness of grouped studs and durability of the composite structure,to provide an alternative for the use of group studs in accelerated steel-concrete composite bridge construction.