Seismic strong motion with long path and risk evaluation in Mexico City

墨西哥城长路径强震及风险评估

基本信息

批准号：
07041111
负责人：
MOCHIZUKI Toshio
金额：
$ 4.42万
依托单位：
TOKYO METROPOLITAN UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for international Scientific Research
财政年份：
1995
资助国家：
日本
起止时间：
1995 至 1996
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07041111/
关键词：
Strong-motion database Long path Wavefield of Mexico Valley Very soft ground Microtremor measurement Seismic risk evaluation system Soil-structure interaction

项目摘要

The 19 September 1985 Hichoacan earthquake (Hs=8.1) caused very severe damage in Mexico City inside the Mexico Valley, which is approximately 400 km from the epicenter in the Pacific Ocean. Whereas the earthquake produced very low accelerations at epicentral stations, seismic waves were amazingly amplified inside the valley, especially in the lakebed zone, and the long duration of the lakebed seismograms was a real surprise. We hypothesize that the long coda in the lakebed zone are produced by multipathing due to the long-distance path and the vibration characteristics, which depend on the valley configuration and the very soft surficial layrs. The following 3 study subjects have been performed. The first subject is the interpretation of wave field in the Mexico City and is composed of 4 topics. The first topic is the construction of database software for strong-motion records. The second topic is the estimation of the long-path effects by basic analysis of strong-motion records along the long path. The third topic is the analysis of array records in Mexico City. The fourth topic is the microtremor measurements along the long path to examine site effects of strong-motion stations. The second subject is the development of general seismic risk evaluation system for Mexico City. Thirdly, we estimate the response of structures on the soft ground of Mexico City, considering soil-structure interaction.

1985 年 9 月 19 日的希却坎地震（Hs=8.1）对墨西哥谷内的墨西哥城造成了非常严重的破坏，距太平洋震中约 400 公里。虽然地震在震中站产生的加速度非常低，但地震波在山谷内部，特别是在湖床区域却惊人地放大，而且湖床地震记录的持续时间之长真是令人惊讶。我们假设湖床区的长尾波是由于长距离路径和振动特性而由多路径产生的，这取决于山谷的构造和非常软的表层。已进行以下 3 个研究课题。第一个主题是墨西哥城波场解读，由4个主题组成。第一个课题是强震记录数据库软件的构建。第二个主题是通过对沿长路径的强运动记录的基本分析来估计长路径效应。第三个主题是墨西哥城数组记录的分析。第四个主题是沿着长路径的微震测量，以检查强运动站的场地效应。第二个课题是墨西哥城通用地震风险评估系统的开发。第三，考虑到土壤与结构的相互作用，我们估计了墨西哥城软土地基上结构的响应。