资料简介: Seismic Collapse Safety of Reinforced Concrete Buildings:I. Assessment of Ductile Moment Frames,Curt B. Haselton1, Abbie B. Liel2, Gregory G. Deierlein3, Brian S. Dean4, Jason H. Chou5Ground motions used for the nonlinear dynamic analyses are recordings from largemagnitude earthquakes (magnitude 6.5 to 7.6) recorded at moderate fault rupturedistances (10 to 45 km). The 39 ground motion record pairs (each with two orthogonal horizontal components) and their selection criteria are documented in Haselton and Deierlein (2007). This ground motion set is an expanded version of the far-field ground motion set utilized in the FEMA P-695 (FEMA 2009).
Ground motion records are selected and scaled without considering the distinctivespectral shape of rare (extreme) ground motions, due to difficulties in selecting andscaling a different set of records for a large set of buildings having a wide range of first-mode periods. To account for the important impact of spectral shape on collapseassessment, shown by Baker and Cornell (2006), the collapse predictions made using thegeneral set of ground motions are modified using a method proposed by Haselton et al.
(2009). The expected spectral shape of rare (large) California ground motions isaccounted for through a statistical parameter referred to as epsilon (ε), which is a measure of the difference between the spectral acceleration of a recorded ground motion and the median value predicted by ground motion prediction equation. A target value of ε=1.5 is used to approximately represent the expected spectral shape of severe ground motions that can lead to collapse of code-conforming buildings (Appendix B of FEMA P-695 2009; Haselton et al. 2010).
钢筋混凝土建筑的抗震安全设计;I.延性框架的分析,Curt B. Haselton1, Abbie B. Liel2, Gregory G. Deierlein3, Brian S. Dean4, Jason H. Chou5应用于非线性动态分析的地面运动是中等深度(10 到45 千米)断层错动引起的震级为6.5至7.6的大地震。Haselton和Deierlein(2007)上记录了这39对地面运动(每两个之间是互相垂直的关系)和他们的选择标准。这些地面运动概况是一个在联邦紧急事务管理局的P -695使用的远场地面运动扩大版本。
由于在选择和调整大量建筑的第一振型时期的记录中遇到了很多难题,所以在选择和调整地面运动记录时没有考虑罕见(极端)的地震频谱形状。为了说明频谱形状对倒塌的重要影响 ,如贝克和康乃尔(2006)所说,预测倒塌使用的是由Haselton等人在2009年提出的一种对一般地震进行修正的方法。加利福尼亚地面运动频谱形状是通过计算一个小量统计参数(ε)来说明的,这方法用来区分记录到的地面运动频谱加速度与由地面运动预测方程式得出的平均值的不同。ε= 1.5的目标值用来粗略代表可能导致建筑物倒塌的剧烈地面运动的频谱形状。(联邦应急管理局P-695 (2009)的附录B ;Haselton et al. 2010)
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