近断层地震动下摇摆-自复位桥墩地震反应分析

发布时间：2018-12-14 15:45

【摘要】：为讨论摇摆自复位(Rocking Self-Centering,RSC)桥墩在近断层地震动下的地震反应,基于Open Sees数值分析平台建立了RSC桥墩抗震分析模型。同时建立了普通钢筋混凝土(Reinforced Concrete,RC)桥墩,配置竖向无粘结预应力筋(Unbonded Prestressed Reinforced Concrete,PRC)桥墩的抗震分析模型作为对比。对各模型输入近断层地震动记录,进行增量动力分析。以墩顶最大位移角、残余位移角、预应力筋最大应力为考察目标,对比分析了不同墩高(剪跨比分别为2、4和6)、不同桥墩类型(RSC、RC和PRC桥墩)时各桥墩的地震反应。结果表明:随着耗能钢筋配筋率增加,RSC桥墩墩顶最大位移角和预应力筋最大应力均减小;RSC和PRC桥墩均可有效减少桥墩震后残余位移角。耗能钢筋配筋率与PRC桥墩纵筋配筋率接近的RSC桥墩,两者的最大墩顶位移角、残余位移角和预应力筋应力水平均接近。无论是RSC桥墩还是PRC桥墩,当剪跨比大于等于6.0时,易发生预应力筋失效。为避免预应力筋失效引起RSC桥墩产生过大的墩顶残余变形,RSC桥墩中耗能钢筋配筋率不宜低于0.75%。
[Abstract]:In order to discuss the seismic response of rocking self-reset (Rocking Self-Centering,RSC) pier under near-fault ground earthquake, the seismic analysis model of RSC pier is established based on Open Sees numerical analysis platform. At the same time, the seismic analysis model of normal reinforced concrete (Reinforced Concrete,RC) pier with vertical unbonded prestressed tendons (Unbonded Prestressed Reinforced Concrete,PRC) pier is established as a comparison. The incremental dynamic analysis is carried out for each model by inputting the near fault ground seismic records. Taking the maximum displacement angle of pier top, residual displacement angle and maximum stress of prestressed tendons as the targets, the seismic responses of different piers with different height (shear / span ratio of 2 ~ 4 and 6) and different pier types (RSC,RC and PRC piers) are compared and analyzed. The results show that the maximum displacement angle at the top of the RSC pier and the maximum stress of the prestressed tendons decrease with the increase of the ratio of energy dissipation reinforcement, while the residual displacement angle of the pier can be effectively reduced by RSC and PRC piers. The maximum top displacement angle, residual displacement angle and stress level of prestressed tendons are close to the maximum displacement angle of PRC piers, where the reinforcement ratio of energy dissipation steel bar is close to that of longitudinal reinforcement ratio of PRC pier. Whether RSC pier or PRC pier, when the shear span ratio is greater than or equal to 6. 0, prestressing tendons are liable to fail. In order to avoid excessive residual deformation at the top of RSC pier caused by failure of prestressed tendons, the ratio of energy dissipation reinforcement in RSC pier should not be lower than 0.75.
【作者单位】：大连理工大学建设工程学部;防灾科技学院防灾工程系;
【基金】：国家自然科学基金项目(51678150) 地震科技星火计划攻关项目(XH17064) 河北省高等学校科学技术研究项目(ZD2017306)
【分类号】：U442.55

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