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，Hichoacan地震（HS = 8.1）在墨西哥山谷内造成了非常严重的破坏，墨西哥山谷距离太平洋的震中约400公里。尽管地震在地下中央站产生了非常低的加速度，但地震波在山谷内部，尤其是在湖床区域内被惊人地放大，而湖泊地震图的长时间是一个真正的惊喜。我们假设，由于长距离路径和振动特征，湖床区的长尾码是通过多路径产生的，这些特性取决于山谷的构型和非常柔软的表面层。以下3个研究对象进行了。第一个主题是对墨西哥城波浪场的解释，由4个主题组成。第一个主题是构建用于强运动记录的数据库软件。第二个主题是通过沿着长路径对强运动记录的基本分析来估计长期路径效应。第三个主题是对墨西哥城阵列记录的分析。第四个主题是沿着长途途径的微晶状体测量值，以检查强度动作站的位点效应。第二个主题是墨西哥城一般地震风险评估系统的发展。第三，考虑土壤结构的相互作用，我们估计墨西哥城柔软地面上的结构的响应。