Based on the design of a typical steel cell of the joint section of an original bridge , a full-scale model test of shear studs and PBL shear connector group was built to study the mechanical properties of steel-concrete composite joint .Static and fatigue loading was carried out on the test model based on the principle of equivalent stress . The test results indicate that the shear studs and the PBL connectors are in linear stress state under de-sign load .Because of the group stud effect , the stress level of the first five rows of the shear studs near the stressed end is comparatively high ,while the stress level of the PBL and the rest of shear studs is low .After the fatigue verification and failure tests , the stress of PBL connectors increases but is still in elastic stress stage .Meanwhile ,the shear studs under greater stress near the stressed end are in plastic stress stage . The transfer of shearing is rearranged for stiffness degradation of the shear studs resulting in the increase of the shear distribution ratio of PBL connectors . The design of the shear connectors of the joint section is safe and reliable , w hich can provide a reference value for the application of the shear connector in practical engineering .%为研究钢-混结合段剪力连接件群的力学性能,根据原桥结合段中典型钢格室设计制作剪力钉和PBL剪力键群足尺试验模型,按照应力等效原则对试验模型进行静力及疲劳加载.试验结果表明:在设计荷载作用下,两种剪力键的应力与应变仍为线性关系;由于群钉效应,靠近施荷端前五排的剪力钉群应力水平较高,PBL剪力键和其余部分剪力钉应力水平较低;疲劳验证和破坏试验后PBL剪力连接件应力水平增大但仍处于弹性受力阶段,靠近施荷端(端部)受力较大的剪力钉已进入塑性受力状态,剪力钉群刚度降低,PBL剪力键传递荷载比例有一定增加;该桥结合段剪力连接件设计安全可靠,可为今后结合段连接键群在实际工程的应用提供参考.
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