连续刚构桥地震反应分析

Seismic Analysis of a Continuous Rigid Bridge

研究目的:为检验双线连续刚构铁路桥在多遇地震和罕遇地震下的抗震性能,参照《铁路工程抗震设计规范》要求,对连续刚构桥进行自振特性分析、多遇地震下的弹性地震反应分析和罕遇地震下的弹塑性地震反应分析。分析过程也可作为高墩铁路桥地震反应分析的一种方法。研究结论:通过自振特性分析,得到该桥的主要自振周期与振型。弹性地震反应分析包括反应谱分析和弹性时程分析,根据分析结果,采用容许应力法对桥墩截面进行抗弯验算。弹塑性地震反应则首先采用纤维模型进行桥墩截面的弯矩-曲率分析,得到截面弹塑性弯曲能力曲线,将其转化为等效的折线模型,作为桥墩相应位置的等效分布塑性铰弯曲特性,进行弹塑性动力分析,得到桥墩截面的弯矩-曲率滞回曲线,从而判定该桥在罕遇地震作用下的抗震性能。分析结果表明该桥满足规范"小震不坏,大震不倒"的抗震设防要求。

Research purposes： In order to verify the seismic performances of the double - line continuous rigid railway bridge, modal analysis, elastic seismic analysis under lowlevel earthquake and elasto- plastic seismic analysis in high - level earthquake are given to a continuous rigid bridge, based on the requirements of the ＂ Code for Seismic Design of Railway Engineering＂. The analysis procedure could be a method in the seismic analysis of high - pier railway bridges. Research conclusions：The vibration modes and periods are acquired in the modal analysis. The elastic seismic analysis includes response spectral analysis and linear time -history analysis. The piers are checked using the allowed stress method. In the elasto - plastic seismic analysis, M - ~b curves of the specified sections of the piers are acquired and hysteresis response curves are calculated so that the seismic performances are obtained. The result shows that the bridge can meet the requirements.