Investigation of Seismic Hazard in Nile Delta Area

尼罗河三角洲地区地震灾害调查

基本信息

批准号：
16404010
负责人：
SATO Tadanobu
金额：
$ 8.38万
依托单位：
Kobe Gakuin University (2006)Waseda University (2005)Kyoto University (2004)
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2004
资助国家：
日本
起止时间：
2004 至 2006
项目状态：
已结题

项目摘要

To conduct seismic hazard analyses in Nail delta area we need the information of ground structure and amplification effect of seismic motion in the area. However earthquake observations and detail ground explorations have not been conducted in Nail delta. The information to be used for determining fault rupture parameters of a future earthquake has not also been corrected although the seismic activities and crust structure and its movement as well as gravity anomaly in the area surrounding Cairo city has surveyed form the beginning of 1950The purpose of this study is to collect data of historical and recent seismic activities surrounding Cairo city for estimating fault mechanisms of earthquakes which caused sever damage to infrastructures in Cairo city. Based on these data we proposed future earthquake scenarios for simulating proper seismic design earthquake motions. The soil exploration data were also collected.Using collected data earthquake motions of a future event are synthesized by superposing stochastic small earthquake motion. To developed a method for synthesize stochastic small earthquake motions using the AR-MA process we collected observed small earthquake motions at several places in Cairo city. The effect of strike, dip angle of the fault and a starting point of rupture on an attenuation of peak acceleration was investigated. The attenuation characteristic of peak accelerations obtained from simulated earthquake motions were studied in order to investigate the relation between peak accelerations and positions of the fault to the observation points. The peak acceleration at the region near the fault was much influenced by the difference of the starting point of rupture as well as the magnitude and the epicenter distance.

为了对钉子三角洲地区进行地震危险性分析，需要了解该地区的地面结构和地震放大效应等信息。然而，钉子三角洲尚未进行地震观测和详细地面勘探。尽管从 1950 年初开始就对开罗市周边地区的地震活动、地壳结构及其运动以及重力异常进行了测量，但用于确定未来地震断层破裂参数的信息也尚未得到纠正。这项研究的目的是收集开罗市周围历史和近期地震活动的数据，以估计对开罗市基础设施造成严重破坏的地震断层机制。基于这些数据，我们提出了未来的地震情景，用于模拟正确的抗震设计地震运动。还收集了土壤勘探数据。利用收集到的数据，通过叠加随机小地震来合成未来事件的地震运动。为了开发一种使用 AR-MA 过程合成随机小地震运动的方法，我们收集了开罗市多个地点观测到的小地震运动。研究了走向、断层倾角和破裂起点对峰值加速度衰减的影响。研究了模拟地震运动得到的峰值加速度的衰减特性，以探讨峰值加速度与断层相对观测点的位置之间的关系。断层附近区域的峰值加速度受破裂起始点、震级和震中距差异的影响较大。