法兰连接预制装配桥墩力学性能分析

Mechanical capacity analysis of prefabricated bridge piers with flange connection

本文提出一种新的预制混凝土桥墩内嵌式法兰拼装方案。基于精细化有限元分析,对潜在拼接位置下的墩柱承载能力、损伤范围、最终失效模式等性能进行了研究。结果表明,法兰位于墩柱塑性铰区以外时,预制墩柱力学性能接近现浇墩柱性能;法兰位于塑性铰区以内时,墩柱承载力随法兰高度的降低而减小,相对于现浇结构,墩柱承载力在达到峰值后下降速率更快,且下降速率受法兰盘位置影响较小;墩柱最终失效破坏主要集中在法兰部位,法兰与下部墩柱接触面出现了撬动分离现象。基于上述结果,对法兰连接预制拼装桥墩的实桥应用给出了相应建议。

A novel connection scheme for prefabricated bridge piers with embedded flange was proposed. High-precision finite element analysis of this kind of piers was conducted. The bearing capacities, damage ranges and final failure modes of the piers with different positions of flange connection were analyzed.The results indicated that once the flange was out of the plastic hinge zone, the mechanical capacity of the prefabricated pier is almost identical with that of the cast-in-place pier. While, once the flange was within the plastic hinge zone, the bearing capacity of the pier decreases with the decrease of flange position. Comparing with the cast-in-place pier, the bearing capacity of the prefabricated pier decreases more rapidly versus lateral displacement after reaching the peak value. The rate of degeneration is independent with the position of flange. Besides, the final failure of the prefabricated pier is mainly due to the failure of flange connection, where the flange separated with the pier and an obvious gap could be observed between the surfaces of these two parts. Based on the above results, some suggestions were proposed to guide the actual design of this bridge.