新型高速铁路客站多维抗震分析的实用反应谱法

A practical response spectrum method for behavior analysis of a novel high speed railway station under multiple earthquake excitations

针对"房桥合一"高速铁路客站不同阻尼比构件、大跨构件较多,对其阻尼模型和多维实用反应谱法进行了研究。首先通过位能加权阻尼和振型分解法的原理,得出位能加权阻尼的激励为各振型响应,并基于单元刚度矩阵推导了位能计算公式。接着在结构自振周期不超过4.5倍场地特征周期的条件下,对水平与竖向加速度互功率谱的表达形式进行了替代。基于两者,利用随机振动理论与反应谱理论推导了能合理考虑各向振型间相关性的实用反应谱公式。最后,以天津西站Ⅱ区为例加以应用,并与时程分析、多种常用多维反应谱组合法进行了比较,说明该公式的合理性,可供同类结构抗震设计与分析作参考。

A high speed railway station with structure-bridge integrated was a complex structure with members having different damping ratios and those with large-span, its damping model and a practical response spectrum method were investigated. Firstly, based on the principles of damping with potential energy weighted and modal decomposition, it was obtained that the excitation of the damping method is the response of each mode and the potential energy calculation formula is deduced based on an element stiffness matrix. Secondly, a rational substitution of cross-power spectrum between X or Y-direction and Z-direction was proposed, if the natural period of the structure was not greater than 4.5 times of the characteristic site period. Then, a practical response spectrum formulation was proposed based On random vibration theory and response spectrum theory. Last, all the calculation formulas were used in a typical case of Tianjin West Railway Station-Ⅱ, comparisons among the results from the formulas, time-history analysis and some commonly used multidimensional response spectra combined method were done, they verified the effectiveness of the proposed method and the formulas provided a reference for design and analysis of the same kind of structures under seismic excitations.