基于不同结构形式新型桥墩抗震性能对比分析

Contrastive Analysis of the Seismic Performance for New Bridge Pier Based on Different Structure Forms

研究目的:在高地震烈度的山岭和峡谷地区高墩大跨连续刚构桥被大量建造的同时,探索和寻求适用于高烈度区该类桥型高墩的新型结构形式非常必要。本文以二郎河特大桥为工程背景,根据该桥双肢薄壁高墩截面(RC墩),基于承载力和墩顶刚度相同的原则,优化设计两种新型高墩截面:钢板连接的钢管混凝土高墩截面(CFS-1墩)和双波折腹板连接的钢管混凝土高墩截面(CFS-2墩);运用OpenS ees建立模型,采用Pushover方法研究这三种高墩截面结构的滞回曲线、累积滞回耗能、等效粘滞阻尼系数、骨架曲线、延性性能、刚度特性,对比分析三种高墩结构抗震性能的优劣。研究结论:(1)相同轴压比条件下,基于滞回曲线、累积滞回耗能、等效粘滞阻尼系数的对比分析,CFS-1墩和CFS-2墩耗能能力远远高于RC墩,CFS-2墩耗能能力略高于CFS-1墩;基于骨架曲线、位移延性系数、等效刚度退化系数的对比分析,CFS-1墩和CFS-2墩塑形变形能力明显高于RC墩,CFS-2墩塑形变形能力略好于CFS-1墩;(2)优化设计的新型CFS-1墩和CFS-2墩的抗震性能总体优于RC墩;(3)CFS-2墩的抗震性能略强于CFS-1墩,说明钢管混凝土柱间的连接方式对整个桥墩的抗震性能有影响,本研究中双波折腹板连接优于钢板连接;(4)本研究成果可供类似桥梁结构体系设计时参考和借鉴。

Research purposes： A large number of long - span continuous rigid frame bridges with high pier were built in the high seismic intensity of the mountain and canyon area, and it is necessary to explore and seek a new type of bridge pier for high seismic intensity area. The Erlang River Super Major Bridge was taken as the engineering background of this paper, according to the double limb thin - walled high pier section （ RC pier） of this bridge and the principle of same bearing capacity and pier - top ＇s stiffness, two new kinds of high pier sections are optimally designed： one is connected by steel plate （CFS -1 pier）, another is connected by double corrugated steel web （CFS -2 pier）. A finite element model was established by OpenSees to study three kinds of high pier structure ＇s characteristics with Pushover method, such as hysteretic loops, accumulative hysteretic energy dissipation, equivalent viscous damping coefficient, skeleton curves, ductility performance, and stiffness characteristics. And their seismic performances were compared and analyzed. Research conclusions： （ 1 ） At the same axial compressive ratio, based on the comparative analysis of hysteretic loops,accumulative hysteretic energy dissipation and equivalent viscous damping coefficient, the result is that CFS - 1 and CFS -2 piers＇energy dissipation is far higher than that of RC while CFS -2＇s energy dissipation is slightly higher than CFS - 1. Based on the comparative analysis of skeleton curves, displacement ductility coefficient and equivalent stiffness degradation coefficient, CFS - 1 and CFS - 2 piers＂ plastic deformation capacity is significantly higher than that of RC and the plastic deformation ability of CFS - 2 is slightly better than that of CFS - 1. （2） The seismic performance of the new optima - designed CFS - 1 and CFS - 2 piers is better than that of RC. （3） The seismic performance of CFS - 2 is slightly better than the performance of CFS - 1, which shows that the connection between piers of concrete - filled steel has impact on piers＇ seismic performance and the connection of double corrugated steel web is better than the connection of steel plate in this study. （4） The research results can provide references and guidances for the design of future similar bridge structural system.