Seismic strong motion estimation with risk evaluation in Mexico City

墨西哥城地震强震估计与风险评估

基本信息

批准号：
09041127
负责人：
MOCHIZUKI Toshio
金额：
$ 5.76万
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：
1997
资助国家：
日本
起止时间：
1997 至 1998
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09041127/
关键词：
Mexico City Soft ground Long-period strong motion Wavefield 3-D nonlinear building response Soil-building interaction system Seismic risk evaluation system

项目摘要

We investigate large-amplitude long-period strong motions with long duration, which caused much building damage in the lakebed zone of Mexico City during the 1985 earthquake. We estimate strong motions reasonably, and perform a building response analysis in the lakebed zone. We evaluate seismic risk in Mexico City, and summarize countermeasures for earthquake disaster prevention. For these purposes, we performed the following 3 research themes.1.Strong motions. (1) We analyzed strong motions recorded at a 3-dimensional, small array station in the lakebed zone of Mexico City. We estimated a theoreticalwavefield, using a shallow and deep structures. Also, we separated body andsurface waves theoretically. Furthermore, we performed a numerical simulation for body-wave propagation, considering nonlinearity and subsidence of soils. (2) We analyzed strong motions recorded at several borehole stations in Mexico City, and investigated wavefields in different geotechnical zones. We estimated some theoretical wavefields using deep structures, and indicated that surface waves were excited by the Mexican Volcanic Belt.2.Buildings. (1) We developed a 3-dimensional nonlinear soil-building interaction analysis, which considered characteristics of strong motions. We performed the interaction analysis for low- to high-rise buildings in the lakebed zone of Mexico-City during the hypothetical Guerrero earthquake, which is similar to the 1985 earthquake. We interpreted much damage to mid-rise buildings during the 1985 earthquake. (2) We conducted the same analysis in different geotechnical zones of Mexico City, and interpreted local differences in damage level.3.Urban disaster prevention. We started to improve an existing seismic risk evaluation system for Mexico City, by considering strong-motion characteristics and building responses. Also, we are estimating economical damage in Mexico City due to some earthquakes.

我们研究了1985年地震期间墨西哥城湖床区大振幅、长周期的强运动，该运动对建筑物造成了很大的破坏。我们合理地估计了强烈的运动，并对湖床区的建筑进行了响应分析。对墨西哥城地震风险进行评估，总结地震防灾对策。为此，我们进行了以下3个研究主题：1.强烈运动。 (1) 我们分析了墨西哥城湖床区 3 维小型阵列站记录的强运动。我们使用浅层和深层结构估计了理论波场。此外，我们从理论上分离了体波和表面波。此外，我们还考虑了非线性和土壤沉降，对体波传播进行了数值模拟。 (2)我们分析了墨西哥城几个钻孔站记录的强运动，并调查了不同岩土区域的波场。我们利用深层结构估计了一些理论波场，并表明表面波是由墨西哥火山带激发的。2.建筑物。 (1) 我们开发了三维非线性土壤-建筑物相互作用分析，其中考虑了强运动的特征。我们对墨西哥城湖床区的低层到高层建筑在假设的格雷罗地震期间进行了相互作用分析，该地震与 1985 年的地震类似。我们对 1985 年地震期间中层建筑的大量损坏进行了解释。 (2)对墨西哥城不同岩土工程区进行了同样的分析,解释了当地受损程度的差异。3.城市防灾。我们开始考虑强震特征和建筑反应，改进墨西哥城现有的地震风险评估系统。此外，我们正在估计墨西哥城因地震造成的经济损失。