挡块界面连接形式对装配式桥梁横向抗震性能的影响

Influence of the Interface Connection Form of the Shear Key on the Lateral Seismic Performance of the Assembled Bridge

针对地震作用下挡块易损伤问题,设计并制作了整体现浇式挡块试件A1和植筋后浇式挡块试件A2。采用6通道MTS仪器开展低周反复拟静力试验,探究界面连接形式挡块对桥梁横向抗震性能的影响,分析了两种界面连接类型挡块的破坏特征、滞回曲线、骨架曲线、耗能能力等。试验结果表明,挡块A1为典型的剪切破坏,挡块A2表现为界面剥离破坏;挡块A1骨架曲线具有典型的三阶段特征,在荷载作用下具有较好的延性;低周反复荷载导致挡块A2界面连接钢筋滑移,挡块抗震能力持续降低,增加植筋数量和锚固深度能有效提升后浇式挡块横向抗震性能。

In view of the problem that the retaining block is easy to be damaged in earthquake,the integral cast-in-place retaining block specimen A1 and the post-pouring retaining block specimen A2 are designed and fabricated.The low-cycle quasi-static test is carried out by the 6-channel MTS instrument to explore the influence of the interface connection block on the lateral seismic performance of the bridge.The failure characteristics,hysteresis curve,skeleton curve and energy dissipation capacity of the two types of interface connection blocks are analyzed.The test results show that the block A1 is a typical shear failure,and the block A2 is an interfacial debonding failure.The skeleton curve of block A1 has typical three-stage characteristics and has good ductility under load.Low cyclic loading leads to the slip of the connecting steel bar at the A2 interface of the retaining block,and the seismic capacity of the retaining block continues to decrease.Increasing the number of planting bars and anchoring depth can effectively improve the lateral seismic performance of the post-pouring retaining block.