地震研究

以Turkey Flat标准试验场为基准场地,以Toro剪切波速模型为基础,进行Monte Carlo模拟,生成剪切波速、层厚和密度随机样本各200条,将各土层随机参数组成4个工况作为不确定分析的基础。采用常用的四分之一波长法和传递函数法计算场地放大因子,分析放大因子以及特征周期对4种工况的敏感度。结果表明:土层剪切波速、层厚和密度的随机性对2种方法计算得到场地放大因子有相同的影响; 剪切波速的随机性对放大因子和特征频率的影响比其他参数大; 四分之一波长法得到的放大因子和特征频率对土层各参数的敏感性弱于传递函数方法。

According to the Toro share velocity model,we use the Monte Carlo method to generate 200 shear velocities,thickness and density random samples for uncertainty analysis,based on soil structure from the Turkey Flat site.Computing the quarter-wavelength(QWL)method amplification factor as well as transfer function(TF)and estimating their sensitivity under four conditions made up of random soil samples mentioned above.The results show that uncertainties of shear velocity,thickness and density have same impact on the spectrum characteristics using two methods.The influence of shear velocity on both amplification factors and fundamental frequency is predominant among different soil parameters.In addition,amplification factors and fundamental frequency of QWL are less sensitive to random soil parameters than that of TF's.

引言
1 研究方法
2 土层随机模型
3 分析和结果
4 结论

表1 Toro(1995)剪切波速模型参数<br/>Tab.1 The parameters of shear-wave velocity of the model from Toro(1995)

表1 Toro(1995)剪切波速模型参数
Tab.1 The parameters of shear-wave velocity of the model from Toro(1995)

表2 基准场地结构和土层随机分布参数<br/>Tab.2 Structure of basic field and random distributed soil parameters

表2 基准场地结构和土层随机分布参数
Tab.2 Structure of basic field and random distributed soil parameters

图1 随机土层参数样本<br/>Fig.1 Samples of randomized soil properties

图1 随机土层参数样本
Fig.1 Samples of randomized soil properties

图2 四分之一波长法计算的4种工况的放大因子曲线<br/>Fig.2 Amplification factor curves of quarter-wavelength method under four conditions

图2 四分之一波长法计算的4种工况的放大因子曲线
Fig.2 Amplification factor curves of quarter-wavelength method under four conditions

图3 传递函数法计算的4种工况的放大因子曲线<br/>Fig.3 Amplification factor curves of transfer function method under four conditions

图3 传递函数法计算的4种工况的放大因子曲线
Fig.3 Amplification factor curves of transfer function method under four conditions

图4 4种工况下2种方法得到的放大因子的标准差随频率的变化曲线<br/>Fig.4 The variations of standard deviation of amplication factors with frequency using two methods under four conditions

图4 4种工况下2种方法得到的放大因子的标准差随频率的变化曲线
Fig.4 The variations of standard deviation of amplication factors with frequency using two methods under four conditions

图5 4种工况对2种方法计算的第一特征频率的影响<br/>Fig.5 The influence on fundamental frequency under four conditions using two methods

图5 4种工况对2种方法计算的第一特征频率的影响
Fig.5 The influence on fundamental frequency under four conditions using two methods

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备注

引言

1 研究方法

2 土层随机模型

3 分析和结果

4 结论

期刊信息