无粘结RC加固铁路重力式桥墩抗震性能试验

(兰州交通大学 土木工程学院,甘肃 兰州 730070)

拟静力试验; 铁路重力式桥墩; 抗震性能; 震后加固; 无粘结RC

Experimental Study on the Seismic Behaviour of the Gravity Railway Bridge Pier Strengthened with Unbonded RC
LIU De'an,DING Mingbo,LU Jinhua,QIN Xuncai,HAO Yan

(School of Civil Engineering,Lanzhou Jiaotong University,Lanzhou 730070,Gansu,China)

quasi-static test; gravity railway bridge pier; seismic performance; post-earthquake reinforcement; unbonded RC

DOI: 10.20015/j.cnki.ISSN1000-0666.2022.0038

备注

为研究无粘结RC加固受损铁路重力式桥墩的抗震性能,制作1个配筋率为0.2%的桥墩缩尺模型进行拟静力试验,破坏后采用无粘结RC进行加固。对加固前后的模型进行低周往复荷载试验,对比分析桥墩加固前后的滞回曲线、骨架曲线、刚度退化及墩顶残余位移等抗震性能指标。结果表明:采用无粘结RC进行墩底局部加固可有效地提高桥墩的耗能能力,从而避免破坏面转移至未加固区; 采用无粘结RC加固,墩顶残余位移较小,桥墩模型的强度、承载能力、刚度和位移延性系数均得到了一定程度提高,无粘结RC加固使得损伤的铁路重力式桥墩抗震性能明显提高,该加固方案对震后桥墩的修复比较有利。
In order to study the seismic performance of the damaged gravity bridge pier of railways strengthened by unbonded RC,a scale model of the pier with reinforcement ratio of 0.2% is made,and a pseudo-static test on the pier is carried out.Low-cycle reciprocating load tests on the model are carried out before and after reinforcement,and the seismic performance indexes of the pier before and after reinforcement,such as hysteretic curve,skeleton curve,stiffness degradation and residual displacement of pier top,are compared and analyzed.The results show that:Local reinforcement of pier bottom with unbonded RC can effectively improve the energy dissipation capacity of the pier,thus keeping the failure surface from transferring to the unreinforced area.By unbonded RC reinforcement,the residual displacement of the pier top becomes small,and the strength,bearing capacity,stiffness and displacement ductility of the pier model are improved to a certain degree.The unbonded RC reinforcement can significantly improve the seismic performance of the gravity bridge pier of railways.This approach can serve as a reference for the repair of the earthquake-damaged piers.
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