作为当前铁路客站建设中经常采用的一种结构形式,“房桥分离”结构在地震激励下存在客站建筑与桥梁结构发生碰撞的隐患,而规范中缺少对于此类结构形式最小安全间距的相关规定。基于此,作者根据客站建筑与桥梁结构的结构形式,并考虑客站建筑的非比例阻尼特征,通过引入虚拟激励法,推导用于碰撞分析的随机表达式,该计算表达式可以实现准确高效的随机运算。在此基础之上,作者进一步提出一种改进差异谱方法,该反应谱组合公式町用于计算地震作用下相邻结构的相对位移,从而提供避免房桥结构震致碰撞的最小安全间距,相比传统方法其可以考虑建筑物非比例阻尼特征,具备坚实理论基础,形式简洁方便,适于工程应用。最后通过数值算例验证本文所提出改进差异谱方法的准确性和有效性。
As an often adopted structural style in current railway station constructions, the separated structure-bridge station under earthquake excitation involves risks of collision between the station and the elevated bridge, meanwhile, there are not corresponding regulations about the safety spacing in the seismic code. Thereby, according to structural style and dynamic properties of the separated structure-bridge station, a stochastic expression for pounding analysis based on the pseudo-excitation method is proposed, and it takes into account of the non-proportional damping characteristics. Accordingly, the spectral difference method is improved for calculating the relative displacement of adjacent buildings in earthquake and thus providing the minimum spacing between the structure and the elevated bridge for avoiding pounding due to earthquakes. Comparing with the conventional method, the improved spectral difference method can explain the non-proportional damping characteristics with solid theoretical foundation and simplicity. Finally, numerical analysis is carried out to verify the spectral difference method.