近断层脉冲型随机地震动模拟方法及结构动力可靠度研究

Simulation method of pulsed random ground motion of near fault and study on structural dynamic reliability

中文关键词: 近断层脉冲地震动  随机模拟  高层框架结构  直接概率积分法  动力可靠度

英文关键词: Near fault pulse ground motion  Stochastic simulation  High-rise frame structure  Direct probability integration method  Dynamic reliability

中文摘要:

      本文以台湾集集脉冲型地震动为数据集建立了一种改进的参数化近断层脉冲型随机地震动模型，首先采用MP03模型和人工蜂群算法从实际地震记录提取低频脉冲部分，建立随机低频脉冲模型；采用谱表示-随机函数法生成高频部分，二者叠加生成近断层脉冲型随机地震。然后，采用蒙特卡洛模拟法和直接概率积分法分别研究非线性单自由度体系和高层框架结构在不同类型地震动作用下的动力可靠度。研究表明：直接概率积分法（DPIM）和蒙特卡洛模拟法（MCS）计算结果基本吻合，但计算效率得到较大提升，可以很好地用于非线性结构的时变可靠度研究；脉冲型地震动与非脉冲型地震动相比能够对结构造成更大的变形，极大降低了结构的可靠度，且近断层距越小影响越显著，低频脉冲是使结构可靠度降低的主要因素，而高频成分对结构可靠度的影响较小。

英文摘要:

      In this paper, an improved parametric near-fault pulse-type stochastic ground shaking model is established using the Taiwan set of pulsed ground shaking as the dataset. First, the low-frequency pulse part is extracted from the actual earthquake records to establish a stochastic low-frequency pulse model, and then the high-frequency part is generated using the spectral representation-random function method, and the two are superimposed to generate the near-fault pulse-type stochastic earthquake. Then, Monte Carlo simulation method (MCS) and direct probability integral method (DPIM) are used to study the dynamic reliability of nonlinear single-degree-of-freedom system and high-rise frame structure under the action of different types of ground shaking, respectively. It is shown that the calculation results of direct probability integral method (DPIM) and Monte Carlo simulation method (MCS) basically match, but the calculation efficiency is greatly improved, which can be well used for the study of time-varying reliability of nonlinear structures; pulsed ground shaking can cause greater deformation to the structure compared with non-pulsed ground shaking, which greatly reduces the reliability of the structure, and the smaller the near-fault distance, the more significant the effect is; low-frequency pulses are the main factor to reduce the reliability of the structure, while high-frequency components have less influence on the reliability of the structure