针对高速铁路客站具有跨度大、节点多、单元多、构件阻尼比差异大等特点,提出实用多维虚拟激励法,从理论上阐明了振型阻尼法求解原理和方法。任取振型,采用修正过滤白噪声谱,利用反应谱能合理考虑激励非平稳性的优点,根据单自由度平稳激励虚拟激励法求得的位移均方差与位移反应谱值相等的原则确定各振型对应的功率谱强度因子。利用多维激励矩阵分解和振型分解原理,提出实用多维虚拟激励法,并以天津西站II区为例将上述理论和方法加以应用。经比较表明:计算结果较常用反应谱组合值大,较时程响应值小,证明该计算方法合理,可供复杂结构的抗震设计与分析参考。
The practical multi-dimension pseudo excitation method was proposed in view of the fact that a highspeed railway passenger station was featured by large span,lots of nodes,multi-number of elements and members with damping ratios of great differences.Firstly,the solving principle and method of the vibration mode damping ratios and other relevant parameters were expounded theoretically.Then,the intensity factor corresponding to every vibration mode,was gotten according to the principle that the displacement variance though the stationary pseudo excitation method with modified white noise spectrum mode for single freedom system,was equal to that using the displacement response spectra reflecting non-stationary property of earthquake.Based on the intensity factor,the practical multi-dimension pseudo excitation was deduced with the decomposition of excitation matrixes and the principle of mode decomposition.Lastly,taking the Tianjin Railway StationII as an example,the above theory and calculation formula were put into application.The computational results were greater than the combinational values of ordinarily used response spectra and smaller than the time-histories responses values.The comparison shows the proposed method is rational and can be seen as references to seismic design of complicated structures.