近断层RC框架结构面向韧性的抗震设计方法研究

近断层脉冲型地震动对建筑结构具有很强的破坏作用，造成了严重的经济损失和人员伤亡。目前我国抗震设计规范并未充分考虑近断层脉冲效应，导致工程结构面临巨大的地震威胁。抗震设计谱是结构抗震设计的基础，主要由四个特征参数确定，而现有方法不能准确识别反应谱特征参数；目前对RC框架结构在不同强度的脉冲型地震动作用下的反应机理尚缺乏科学的认识，我国抗震规范的等效侧向力分布模式无法保证结构在强震作用下各楼层的材料充分发挥。抗震韧性为结构抗震设计提供了新的思路。鉴于此，本项目将开展以下工作：(1)建立近断层抗震设计谱；(2)揭示RC框架结构在不同强度的脉冲型地震动作用下的反应机理，确定相应的侧向力分布模式；(3)提出基于结构设计基准期的抗震韧性评价模型，以等效侧向力分布模式为切入点给出提高RC框架结构抗震韧性的设计方法。本项目对完善现有抗震设计理论，减少近断层震害损失，提高工程结构抗震韧性具有重要的现实意义。

Near-fault pulse-like ground motions have been known to impose significant demands on many engineered structures, causing serious economic losses and casualties. Unfortunately, the current Chinese seismic design code does not fully consider this effect. The seismic design spectra, which is determined based on four characteristic parameters, is the basis of the seismic design of structures. Existing methods cannot accurately estimate the characteristic parameters of response spectra. The dynamic mechanism of RC frame structures under pulse-like ground motions with different intensities is not well understood. In addition, the material properties cannot be fully utilized for structures designed based on the equivalent static seismic lateral force patterns in current seismic design codes. Resilience-based seismic design is becoming a trend in earthquake engineering. To this end, this project will conduct the following work: (1) constructing the near-fault seismic design spectra; (2) revealing the dynamic mechanisms of RC structures under near-fault pulse-like ground motions in different levels of intensity and the corresponding story lateral force pattern will be determined and (3) establishing the structural seismic resilience model based on the structural service life, and provides some suggestions of how to increase the structural resilience in seismic design. This project has significant practical meanings in improving the current seismic design, reducing the seismic losses in the near-fault region and in improving the structural seismic resilience.