装配式钢-薄层超高性能混凝土组合梁大直径群钉连接件抗剪性能数值分析

Numerical Study on Shear Performance of Grouped Large Headed Stud Connectors in Prefabricated Steel-Thin UHPC Composite Girder

为研究大直径群钉连接件在装配式钢-薄层超高性能混凝土组合梁桥中的抗剪性能,通过有限元软件ABAQUS建立了19个推出试件模型。着重分析了浇筑方式、栓钉间距、键群间距和键群数量对试件抗剪承载力、抗剪刚度和荷载-滑移曲线的影响规律。研究结果表明:试件破坏模式主要表现为栓钉根部的剪断以及混凝土的局部压碎;使用预制超高性能混凝土板推出试件的抗剪承载力比现浇试件降低10%以内;栓钉间距小于2.5倍栓钉直径时,试件抗剪承载力明显下降;随着键群间距和数量的增加,键群中单个栓钉的抗剪承载力以及抗剪刚度减小。针对装配式钢-薄层超高性能混凝土大直径群钉连接件提出了预测其荷载-滑移关系的理论模型,并将抗剪承载力试验结果与规范计算结果进行了比较,得到了适用于装配式钢-薄层超高性能混凝土组合梁桥大直径群钉连接件的计算方法。

In order to study the shear performance of grouped large headed stud connectors in prefabricated steel-thin UHPC composite girder,19 push-out specimens were established by finite element software ABAQUS to study the influence of casting method,stud spacing,key group spacing,and key group number on the shear bearing capacity,shear stiffness,and load-slip curve of the specimens.The results showed that the failure mode of specimens was mainly the shear failure at the root of studs and the local crushing of concrete slabs.The shear bearing capacity of prefabricated specimens was reduced by 10%compared with the cast-in-place specimens.The shear bearing capacity of the specimens decreased significantly when the spacing of studs was less than 2.5 times the diameter of studs.The shear bearing capacity and shear stiffness of individual stud in the key group were reduced by the increase of the spacing and number of key groups.The theoretical model for predicting the load-slip relation of the prefabricated steel-thin UHPC grouped large headed stud connectors was proposed.Moreover,the results of the shear capacity from ABAQUS were compared with the calculated results from the code,and a design method for prefabricated steel-thin UHPC composite girder bridge grouped large headed stud connectors was obtained.