不同类型地震波作用下非线性场地的行波效应分析
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摘要
目前有关场地的非线性行波效应分析,大多是基于场地土的等效线性化模型.本文通过对ANSYS软件的二次开发,采用双曲线模型模拟场地土的非线性,分别选取长周期基岩地震波和普通地震波作为输入,对某深覆盖土层场地进行了行波效应分析,探讨不同类型地震波作用下深覆盖土层场地的非线性行波效应问题.本文算例结果表明:在长周期基岩地震波作用下土层地表加速度放大系数值明显大于普通地震波作用下的结果;随着视波速的减小,土层对地震波的水平加速度放大效应也是减小的,但是对于竖向加速度放大系数而言,随着视波速的减小,其放大系数是增大的;一致输入相比于行波输入有放大土层特征周期响应而抑制非特征周期区段的响应的作用.
Most of the analysis of traveling waves effects for nonlinear sites is based on equivalent linear model at present.In this study,a hyperbolic model is used to simulate the nonlinearity of soil sites by the secondary development of ANSYS.This study investigates the traveling wave effects for nonlinear soil layer with deep deposit under both long-period bedrock seismic excitation and general seismic excitation.It is shown that acceleration amplification coefficients of soil layer under long-period bedrock seismic excitation are bigger than those under general seismic excitation.With the seismic wave velocity decreases,horizontal acceleration amplification coefficients of soil layer under traveling wave excitation are smaller,while the vertical acceleration amplification coefficients get bigger.General seismic excitation amplifies the effects of soil layer on characteristic periods but restrains the others more than traveling wave excitation
Most of the analysis of traveling waves effects for nonlinear sites is based on equivalent linear model at present.In this study,a hyperbolic model is used to simulate the nonlinearity of soil sites by the secondary development of ANSYS.This study investigates the traveling wave effects for nonlinear soil layer with deep deposit under both long-period bedrock seismic excitation and general seismic excitation.It is shown that acceleration amplification coefficients of soil layer under long-period bedrock seismic excitation are bigger than those under general seismic excitation.With the seismic wave velocity decreases,horizontal acceleration amplification coefficients of soil layer under traveling wave excitation are smaller,while the vertical acceleration amplification coefficients get bigger.General seismic excitation amplifies the effects of soil layer on characteristic periods but restrains the others more than traveling wave excitation
引文
[1]齐文浩,薄景山,张忠利.土层地震反应分析的研究现状[J]:世界地震工程.2010,26(增刊):368-372.
[2]卢滔,周正华,霍敬妍.土层非线性地震反应一维时域分析[J]:岩土力学.2008,29(8):2170-2176.
[3]潘旦光,楼梦麟,范立础.多点输入下场地非线性地震反应分析计算模型[J]:同济大学学报.2002,30(12):1411-1416.
[4]Robert Pyke.Nonlinear Soil Models for Irregular Cyclic Loadings[J].Journal of the Geotechnical Engineering Division,ASCE,1979,105(GJ6):715.
[5]徐植信,翁大根.上海地区抗震设计反应谱研究[J]:同济大学学报(自然科学版).1993,21(1):9-16.
[6]乔冠东,楼梦麟.大型沉井基础地震反应分析中侧向边界的影响[J]:工程力学.2012,29:111-114.
[7]金星,孔戈,丁海平.水平成层场地地震反应非线性分析[J]:地震工程与工程振动.2004,24(3):38-43.
[2]卢滔,周正华,霍敬妍.土层非线性地震反应一维时域分析[J]:岩土力学.2008,29(8):2170-2176.
[3]潘旦光,楼梦麟,范立础.多点输入下场地非线性地震反应分析计算模型[J]:同济大学学报.2002,30(12):1411-1416.
[4]Robert Pyke.Nonlinear Soil Models for Irregular Cyclic Loadings[J].Journal of the Geotechnical Engineering Division,ASCE,1979,105(GJ6):715.
[5]徐植信,翁大根.上海地区抗震设计反应谱研究[J]:同济大学学报(自然科学版).1993,21(1):9-16.
[6]乔冠东,楼梦麟.大型沉井基础地震反应分析中侧向边界的影响[J]:工程力学.2012,29:111-114.
[7]金星,孔戈,丁海平.水平成层场地地震反应非线性分析[J]:地震工程与工程振动.2004,24(3):38-43.
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