钢筋混凝土圆截面桥墩抗震加固方式对比分析

为研究不同加固方式对钢筋混凝土(RC)圆截面桥墩抗震性能的影响,利用OpenSees有限元软件建立了普通RC桥墩以及分别采用钢套管、碳纤维增强聚合物(CFRP)、体外预应力筋进行加固的桥墩数值分析模型,对模型输入远断层地震动,进行增量动力分析。以墩顶峰值位移角与震后残余位移角为指标,对比分析了桥墩加固前后的地震响应。结果表明:采用钢套管、体外预应力筋和CFRP加固后,RC桥墩的峰值位移与震后残余位移均减小,钢套管加固方式对桥墩峰值位移的降低幅度最大,体外预应力筋加固方式对抑制桥墩震后残余位移的效果最好;随着剪跨比的增大,3种加固方式对桥墩在地震动作用下位移响应的抑制作用均逐步减小;随着轴压比的增大,3种加固方式对RC桥墩峰值位移的抑制作用逐步降低。

Comparison and analysis of seismic reinforcement methods for circular reinforced concrete bridge piers

In order to study the effect of different reinforcement methods on seismic performance of circular reinforced concrete (RC) bridge piers, the numerical models of RC bridge piers and piers strengthened with steel tube, carbon fiber reinforced polymer (CFRP) and external prestressed tendons were established by using OpenSees finite element software. The incremental dynamic analysis was conducted for all the models under the far-fault ground motions. The seismic response of RC bridge piers and strengthened bridge piers were compared and analyzed based on the maximum drift ratio and the residual drift ratio. The results show that the maximum displacement and residual displacement of RC bridge pier are reduced after retrofitted with steel tube, external prestressed tendons and CFRP. The steel tube reinforcement method has the largest reduction of the maximum displacement of the pier, and the restraint effect of external prestressed tendon reinforcement method on residual displacement of pier is the best. With the increase of the shear span ratio, the restraint effect of the three reinforcement methods on the displacement response of piers under ground motion is gradually reduced. With the increase of axial compression ratio, the restraining effect of the three reinforcemen methods on the peak displacement of RC bridge pier gradually decreases.