U 型 Twin-PBL 剪力键极限承载力的数值分析

根据端部承压混凝土可提高Twin-PBL剪力键承载能力的特点，提出一种新型的可用于装配式钢混组合结构的间断式U型Twin-PBL剪力键。通过3组推出试验试件的非线性数值模拟分析，研究了这种新型剪力键的极限承载特点和承载力。结果表明：U型Twin-PBL剪力键极限承载能力较普通承压型Twin-PBL剪力键有显著提高，且提高主要来源于端部混凝土承压面积增大，所以混凝土强度的提高对该剪力键承载能力影响明显，而孔中混凝土榫和贯穿钢筋两部分对承载力贡献无明显变化，故而通过修正端承压混凝土面积得到了这种剪力键承载力计算公式。研究结果为装配式钢-混凝土组合梁桥的间断式剪力键提供了新的思路。

Numerical Analysis on Ultimate Bearing Capacity of U-type Twin-PBL Shear Connector

According to the characteristic that the bearing capacity of Twin-PBL shear connector can be improved by the end-bearing concrete, a new type of discontinuous U-type Twin-PBL shear connector able to be used for prefabricated steel-concrete composite structure is proposed. Through the nonlinear numerical simulation analysis of three groups of push-out test specimens, the ultimate bearing characteristics and bearing capacity of this new hear connector are studied. The results show that the ultimate bearing capacity of U-type Twin-PBL shear connector is significantly higher than that of common pressure-bearing type Twin-PBL shear connector, and the improvement mainly comes from the increase of end-bearing area of concrete. Therefore, the improvement of concrete strength has a significant influence on the bearing capacity of this shear connector. However, the contribution of concrete tenon and penetrating steel to the bearing capacity has no obvious change. Therefore, the computational formula of the bearing capacity of U-type Twin-PBL shear connector is presented by modifying the area of the end-bearing concrete.