预张预应力-承插式预制桥墩抗震试验数值仿真

Numerical simulation of seismic tests for pre-tensioned prestressing precastbridge columns with socket connection

为充分利用承插式桥墩施工容差大、无黏结预应力桥墩震后可自恢复的优势,同时减少现场预应力张拉施工,提出一种承插式连接和工厂预张无黏结预应力筋连接的混合连接预制拼装桥墩。采用ABAQUS软件建立了该桥墩的三维有限元模型,基于已开展拟静力试验结果验证了该数值模型的精确性,并分析了桥墩的局部损伤、滞回行为、骨架曲线、耗能能力以及预应力筋张拉力、接缝开口等行为。结果表明:该研究建立的数值模型可以较好地再现拟静力结果,混合连接预制拼装桥墩力-位移曲线表现为“旗帜型”;当墩顶偏移率为5%时,墩柱仅出现横向裂缝,无其他明显结构损伤;当承插深度为0.4D时,承台出现轻微裂缝,当承插深度为0.7D时,承台可以提供足够的抗拔力且无明显损伤;外包钢管和钢垫板存在应力集中现象。

In order to make full use of the advantages of the large construction tolerance of socket piers and the self-resetting ability of unbonded prestressed piers after earthquakes,and reduce the on-site prestressed tensioning construction,a kind of hybrid connection prefabricated pier furnished with socket connection and factory pretensioned unbonded prestressed reinforcement was proposed.A three-dimensional finite element model of the bridge pier was established by using the ABAQUS software.The accuracy of the numerical model was verified based on the quasi-static test results.The local damage,hysteretic behavior,skeleton curve,energy dissipation capacity,prestressed tendon tension,joint opening and other behaviors of the bridge pier were analyzed.The results show that the numerical model established can reproduce the quasi-static results well,and the force-displacement curve of the precast pier with hybrid connection is“flag type”.When the deviation rate of pier top is 5%,only transverse cracks appear on the pier column,without other obvious structural damage.When the socket depth is 0.4 D,the cap has slight cracks,and when the socket depth is 0.7 D,the cap can provide sufficient uplift resistance without obvious damage.There is stress concentration in the outer steel pipe and steel backing plate.