Development of Comprehensive Guidelines for Preprocessing Simulated Acceleration Time Histories

摘要目前，考虑空间变异性的生命线系统地震反应评价仅依赖于模拟地震动。数值（有限元）代码允许空间可变运动作为结构支撑的激励，需要位移时程作为输入激励。通过模拟加速度时程的直接二重积分得到的位移时程不能显示出真实的波形，因为纯粹由于数值原因，加速度在低频范围内可能包含较大的随机振幅变化。因此，这种模拟的加速度时程也需要预处理。然而，对于它们的预处理没有商定的方法，预处理方案留给研究者自行决定。本研究将利用地震学的最新发展，将其扩展到模拟和条件模拟时程的特定需求，并为其预处理提供指导。将采取以下步骤：(i)从文献中可用的模拟方案中选择常用的模拟方案，以供本研究调查；（ii）应用地震学界开发的最先进的预处理方案来模拟地震运动；（iii）通过评估一个简单结构模型在空间可变激励下的响应统计量来量化步骤（ii）的结果。指引的发展，连同用户友好的（MATLAB）代码，将在万维网上公布，供社区直接使用。

AbstractAt the present time, the seismic response evaluation of lifeline systems incorporating spatial variability relies solely on simulated ground motions. Numerical (finite element) codes permitting spatially variable motions as excitations at the structures supports require displacement time histories as input excitations. Displacement time histories obtained through direct double integration of simulated acceleration time histories do not exhibit realistic waveforms, because, due to purely numerical reasons, accelerations can contain large random amplitude variability in the low frequency range. Hence, such simulated acceleration time histories also require preprocessing. There is, however, no agreed-upon approach for their preprocessing and the preprocessing scheme is left to the discretion of the investigator.This study will utilize recent developments in seismology, extend them to the specific needs of simulated and conditionally simulated time histories, and provide guidelines for their preprocessing. The following steps will be undertaken: (i) selection of commonly used simulation schemes from the ones available in the literature to be investigated in this study; (ii) application of state-of-the-art preprocessing schemes developed by the seismological community to simulated motions; and (iii) quantification of the results of step (ii) through the evaluation of the response statistics of a simple structural model subjected to spatially variable excitations. The development of the guidelines, along with user-friendly (MATLAB) codes will be posted on the World Wide Web for direct use by the community.