济南东站大跨拱结构多点输入地震反应分析

Time-history analysis of Jinan East Station under multi-support and multi-dimension seismic excitation

济南东站屋盖结构为全覆盖复杂双曲面落地拱结构体系,屋盖纵向长度为406. 6m,最大跨度为156m,有必要进行多维多点输入地震反应分析。本文介绍了多点输入地震反应分析的基本原理,对济南东站屋盖结构采用时程分析法,进行了考虑行波效应的水平双向多点输入地震反应分析,将多维多点输入结果与多维单点输入结果进行比较,得出结论为,多点输入的非同步性将增加结构的扭转效应,降低基底总剪力,且随着视波速的减小,扭转效应增大,基底总剪力减小。多点输入对竖向构件的影响较大,对边跨影响大于中间跨。施工图设计中针对不同类型和部位的构件,给出了考虑多点输入影响的地震作用效应调整系数,经验算,全部构件均满足规范要求。研究结果对大型铁路客站的抗震分析有指导意义。

Jinan East Station is an irregular in structural form, with longest dimension of 406.6 m in the long direction. Seismic analysis under multi-support and multi-dimension excitation is needed to be carried out. In this paper, the principle for multi-support and multi-dimension excitation seismic analysis is introduced. Time-history seismic analysis considering traveling effect and double direction input is carried out. The results from multi-support and multi-dimension seismic analysis are compared with the results from single-support and multi-dimension analysis, the conclusion shows that the torsional effect increases obviously and the total shear force of the base decreases significantly. The variation amplitude of the torsional effect increasing and the total shear force decreasing changes massively with the decrease of the apparent wave velocity. Multi-support excitation has larger effect on the vertical members, and the effect on the side span is larger than on the middle span. Some suggestions are put forward according to the analysis results. This article provides a method for the consideration of multi-support excitation in the large-sized structure in design.