【摘要】 考虑地震动的随机性及频率和强度非平稳性,利用作者所提出的基于强度和能量控制的随机地震动模型,建立了非平稳随机地震反应分析方法。以某特大型桥梁群桩基础为研究对象,将群桩-土-桥墩结构体系作为一个整体进行了特大型桥梁桩基非平稳随机地震反应分析。首先,基于目标加速度时程的强度和能量信息确定了作为输入的加速度时-频演变功率谱密度;其次,分析了非平稳随机过程激励下自由场和桥梁桩基相互作用体系的地震反应,探讨了非平稳随机过程激励下的群桩-土-桥墩结构动力相互作用;最后,通过比较强度非平稳随机过程和完全非平稳随机过程激励下桥梁桩基相互作用体系的地震反应,探讨了频率非平稳性对相互作用体系地震反应的影响。更多还原

【Abstract】 In this paper, the non-stationary stochastic seismic motion model presented by authors is used to analyze stochastic seismic response of a supergiant pile group foundation employed to support the bridge. The pile group-soil-pier structure is treated as a whole and the finite element method and complex response technique are used to perform the analysis. Firstly, the input time-frequency evolutionary power spectrum is defined according to the intensity and energy information of target acceleration time-history. Secondly, stochastic seismic responses of a free field and a pile group-soil-pier structure system under a nonstationary stochastic seismic excitation are analyzed respectively, and the dynamic pile group-soil-pier structure interaction is discussed. Finally, the effects of frequency nonstationarity on seismic responses of the interaction system are discussed.更多还原