宁句城轨预应力预制桥墩抗震性能试验研究

Experimental Study on Seismic Performance of Prestressed Precast Pier of Ningju Intercity Rail Transit

采用预制拼装技术可以加快桥梁的施工速度和提高施工质量,近年来也逐渐受到地铁工程界的关注。由于对预制桥墩抗震性能的担忧,很难在重要工程和强震区采用。本文以宁句城际轨道预制拼装桥墩为背景,开展现浇、预制和预应力预制桥墩的抗震性能试验研究。结果表明:有粘结预应力可明显提高预制桥墩的强度、极限位移、位移延性和抗震自恢复性,减小单圈耗能能力,可有效地抑制预制桥墩的柱脚滑移。通过在纤维有限元模型中引入零长度滑动弹簧单元,解释了周期性的销栓-摩擦效应。预制桥墩的模拟滞回曲线与试验滞回曲线吻合较好,能有效模拟滞回曲线捏缩现象。当预制桥墩应用在中高地震区时,建议采用预应力筋。

Prefabrication assembley technology can accelerate bridge construction and improve construction quality.In recent years,it has gradually been paid more and more attention to in the subway engineering industry.It is difficult to use precast bridge piers in important engineering or meizoseismal area due to concern of the seismic performance.In this paper,experimental study on seismic performance of cast-in-place,precast and prestressed precast bridge piers is carried out with the precast bridge piers of the Ningju intercity rail transit as the background.The research results show that the bonded prestressing tendon can obviously improve the strength,ultimate displacement,displacement ductility and seismic resilience of the precast bridge pier,reduce the energy dissipation capacity of the single cycle,and effectively suppress the slip between the column foot and the foundation.The periodic dowel-friction effect is explained by introducing zero length sliding spring element into the fiber finite element model.The simulated hysteresis curve of the precast bridge pier is in good agreement with the experimental one,and the pinching phenomenon of the hysteresis curve can be simulated effectively.Prestressing tendon technology is preferred when precast bridge pier is used in medium-high seismic zones.