高烈度区波纹管连接预制拼装桥墩抗震性能研究

Seismic performances of prefabricated assembled piers connected with corrugated pipes in high intensity seismic areas

为探究预制桥墩在高烈度区应用的可行性,提出一种新型的内外波纹管连接墩柱-盖梁节点。设计制作了2个相似比为1∶3的试件,分别为内外波纹管连接桥墩(internal and external corrugated pipe-connected pier,IOCPCP)和现浇桥墩(cast-in-place pier,CIP)。采用拟静力试验方法与有限元数值模拟结合的方法,分析试件的滞回性能、耗能能力、曲率等,并讨论其破坏模式。试验结果表明:试件破坏模式均为墩底塑性铰破坏;IOCPCP试件在承载力、滞回、耗能等方面与现浇桥墩类似,并具有更好的延性能力;IOCPCP试件在大纵漂率6%的作用下仍能保持峰值荷载88%以上的承载力;针对墩柱纵筋强度和内部补偿钢筋长度参数进行有限元模型分析,认为提高墩柱纵筋强度可以使墩底塑性铰区域略有减小,但对外围波纹管内灌浆料强度要求更高;内部补偿钢筋长度较短时,易出现双塑性铰现象。试验结果可为预制拼装桥墩在高烈度地区的工程应用提供参考。

In order to investigate the application feasibility of prefabricated assembled piers in high-intensity seismic areas,a new type of pier-cap joint connected with inner and outer corrugated pipes was proposed.Two specimens with a scale ratio of 1∶3 were designed and fabricated as the internal and external corrugated pipe-connected pier(IOCPCP)and cast-in-place pier(CIP),respectively.By using the method of quasi-static test and finite element numerical simulation,the hysteretic performance,energy dissipation capacity,curvature of the specimen,as well as the failure mode were analysed.The test results show that the specimens are all damaged in the plastic hinge zone at the bottom of the pier;the IOCPCP specimen is similar to the CIP in the performances of bearing capacity,hysteresis,and energy dissipation,whereas has better ductility;the IOCPCP specimen can still maintain the bearing capacity of more than 88%of the peak load under the drift ratio of 6%.The parameter analysis accounting for the strength of the longitudinal reinforcement and the length of the internal compensation reinforcement of the pier column was carried out.It is considered that the increase in the strength of the pier column longitudinal reinforcement can slightly reduce the plastic hinge area at the bottom of the pier,but requires higher strength of the grout in the peripheral corrugated pipes;when the length of the internal compensation reinforcement is short,double plastic hinges are prone to occur.The test results provide a reference for the engineering application of prefabricated assembled piers in high-intensity seismic areas.