摘要
土工结构在地震荷载下的滑动位移是评估结构安全性能的重要参数。采用一种新型的地震波选择方法,在强震数据库中选择修改地震波,以有效地在结构动力分析中引入不同特征地震波的影响。通过一个简单的土工结构地震滑移模型,系统地分析了结构基本周期和滑动面屈服系数对地震滑移概率及相应滑移距离的影响,并提出了滑动体在不同地震场景和基本周期条件下的滑移概率和累积滑动位移的统计模型,对基于性能的土工结构抗震设计具有重要的参考意义。
Earthquake-induced sliding displacement is an important parameter for seismic design of earth structures.Using a novel ground motion selection method,we select and modify ground motions from a strong motion database to capture the median,standard deviation and correlations of response spectra of an earthquake scenario,making it an effective method to incorporate ground motion variability into dynamic time-history analysis of earth structures.Using the selected ground motions and a simple analytical model,the statistical properties of permanent sliding-displacement of earth structures were studied under various earthquake scenarios.The study revealed the influence of structural periods and yielding coefficients of the sliding interface on the statistical distributions of the earthquake-induced sliding displacements.Finally,a model is proposed for the sliding probability and sliding displacements of earth structures conditioned on various earthquake magnitude and rupture scenarios and different fundamental periods.It is demonstrated that the ground motion selection method can effectively represent ground motion variability of different earthquake scenarios.The results have important implications in performance-based earthquake design of earth structures.
引文
[1]顾淦臣.土石坝地震工程[M].南京:河海大学出版社,1989:208-280.
[2]BAKER J W,JAYARAM N.Correlation of spectral acceleration values from NGA ground motion models[J].Earthquake Spectra,2008,24(1):299-317.
[3]WANG G.A ground motion selection and modification method capturing response spectrum characteristics and variability of scenario earthquakes[J].Soil Dynamics and Earthquake Engineering,2011,31:611-625.
[4]ABRAHAMSON N A,AKINSON G,BOORE D,et al.Comparisons of the NGA ground-motion relations[J].Earthquake Spectra,2008,24(1):45-66.
[5]NEWMARK N M.Effects of earthquakes on dams and embankments[J].Géotechnique,1965,15(2):139-160
[6]MAKDISI F I,SEED H B.Simplified procedure for estimation dam and embankment earthquake induced deformation[J].Journal of the Geotechnical Engineering Division,ASCE,1978,104(GT7):849-868.
[7]RATHJE E M,BRAY J D.Nonlinear coupled seismic analysis of earth structure[J].Journal of Geotechnical and Geoenvironmental Engineering,2000,126(11):1002-1215.
[8]BRAY J D,TRAVASAROU T.Simplified procedure for estimating earthquake-induced deviatoric slope displacements[J].Journal of Geotechnical and Geoenvironmental Engineering,2007,133(4):381-392.
[9]RATHJE E M,BRAY J D.An examination of simplified earthquake induced displacement procedures for earth structures[J].Canadian Geotechnical Journal,1999,36(1):72-87.
[10]CHOPRA A K.Dynamics of Structures[M].New Jersey:Prentice Hall,2001:309.