A Study on Earthquake Response Characteristics of Small Sedimentary Basin

小型沉积盆地地震响应特征研究

基本信息

批准号：
17560510
负责人：
MIURA Kenji
金额：
$ 1.66万
依托单位：
HIROSHIMA UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2005
资助国家：
日本
起止时间：
2005 至 2006
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-17560510/
关键词：
sedimentary basin site response underground structure finite element method

项目摘要

The purpose of this research is set on the evaluation of site response characteristics for the small sedimentary basins such as Mihara and Kure city, Hiroshima prefecture, Japan. Based on the results of observations of microtremors and the compiled boring data, the precise underground structure models for these regions were constructed. The models were simplified and employed for the numerical simulation analyses. The parameters for the analyses were the dip angle of slant strata, soil property and so on. The concluding remarks of the study are summarized as follows:・Boring data collected in Mihara and Kure city were arranged and compiled into a database.・Distributions of predominant period of ground in the target area were estimated based on H/V spectral ratios of microtremors.・Empirical relation between the predominant period of ground and the depth down to the engineering bedrock was proposed.・Deep underground structures down to bedrock layer of Vs= 2 km/sec were estimated by array observations of microtremors.・Response velocity calculated by the FEM for period ranges of 0.5-2 seconds in the coastal area are 3-5 times larger than that in the mountainous area.・Seismic motions calculated by the FEM is larger than those by 1-D analysis in area where underground structures rapidly shift from horizontally layered to slope. This tendency depends on the dip angle of the slant layer.・Increase of the dip angle of the slant layer brings expansion of the area where earthquake motions influenced by the slant layer are observed.・Seismic motions are amplified greatly in the area above the bottom of the gorge due to valley structure like character "V". This tendency becomes remarkable with increase of the dip angle.

这项研究的目的是评估日本广岛博览会的Mihara和Kure City等小型沉积贝司的现场响应特征。基于微晶体的观察结果和编译的无聊数据的结果，构建了这些区域的确切基础结构模型。简化了模型并用于数值仿真分析。分析的参数是倾斜地层，土壤特性等的倾角。总结了该研究的结论如下：・在Mihara和Kure City中收集的无聊数据被安排并编译到数据库中。・基于h/v的频谱基于h/v的光谱比率，估计了目标区域中主要的基础周期的分布。至vs = 2 km/sec的基岩层，我们通过阵列的微晶体观测值估计。・源vem在沿海地区的周期范围0.5-2秒计算出的响应速度比山区大的3-5倍。在山区中，由FEM计算出的地震运动比1-D在区域中较大的层次转移，而在区域中，较大的层次分析范围是较大的，而在区域中，较大的位置范围较大。这种趋势取决于倾斜层的倾角。・倾斜层的倾角增加带来了观察到受倾斜层影响的地质运动的区域的膨胀。・地震运动在峡谷底部以上的区域在峡谷底部的底部大大扩展。随着倾角的增加，这种趋势变得显着。