The geotechnical effects of long human habitation (2000< years): Earthquake induced landslide hazard in the city of Zefat, northern Israel
The geotechnical effects of long human habitation (2000< years): Earthquake induced landslide hazard in the city of Zefat, northern Israel
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DOI：
10.1016/j.enggeo.2007.07.008
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发表时间：
2007-12
影响因子：
7.4
通讯作者：
O. Katz;O. Crouvi
中科院分区：
文献类型：
--
作者：
O. Katz;O. Crouvi
这项工作研究了长期人类居住对场地岩土条件的影响。它的重点是位于以色列北方死海变换边界的泽法特市。Zefat市在历史地震中遭受了严重的破坏和生命损失，这是地震诱发山体滑坡（EILS）的后果。在这项工作中，我们评估了当前的EILS危险的泽法特市使用基于GIS的区域纽马克分析，校准计算的纽马克位移（代表EILS危险）使用的现场证据和历史文件的地图证明，在历史上发生的地震斜坡不稳定。我们发现，Zefat的核心城市是建立在一个分层的人为材料，几米深，沉积作为超过2000年的人类居住的结果。人类活动产生的物质在机械上是脆弱的，易受斜坡破坏和地震震动放大的影响。它是造成这座城市在历史地震中遭受破坏的原因，也是目前高地震危险的根源。我们的模型表明，地震震级（Mw）5，6和7在距离高达10公里，50公里和100公里以上，分别有可能在Zefat的核心城市诱发山体滑坡。城市目前的工程状况很差，因此，除非做出重大的工程努力，否则在未来的地震中，由于EILS，预计会造成严重的破坏和生命损失。东地中海地区具有可比的长期居住历史的城市（例如，耶路撒冷、太巴列、纳布卢斯、安曼）的旧路段预计也会出现类似的岩土工程问题，建议采取适当的工程措施，以减少未来地震中的破坏和生命损失。然而，根据报告的当地破坏情况评估历史地震震级可能会导致高估震级，因为受损场地建在人为的岩屑堆上（死海转换附近的常见环境）。
This work studies the effects of long human habitation on site geotechnical conditions. It is focused on the city of Zefat that is located on the borders of the Dead Sea Transform in northern Israel. The city of Zefat, suffered severe damage and loss of life in historical earthquakes, as a consequence of earthquake induced landslides (EILS). In this work we evaluate the current EILS hazard for the city of Zefat using a GIS-based regional Newmark analysis, with calibration of the calculated Newmark displacement (representing EILS hazard) using maps of field evidence and historical documents testifying to slope instability that occurred in historical earthquakes. We found that the core city of Zefat is built on a layered anthropogenic material, few meters deep which, was deposited as a result of more than 2000 years of human habitation. The anthropogenic material is mechanically weak, susceptible to slope failure and to amplification of seismic-shaking. It is responsible for the city's devastation in historical earthquakes and it is the source for the current high seismic hazard as well. Our model shows that earthquakes of magnitudes (Mw) 5, 6 and 7 at distances of up to 10 km, 50 km and more than 100 km, respectively, are likely to induce landslides in the core city of Zefat. The current engineering status of the city is poor, and as a consequence severe damage and loss of life are expected in future earthquakes due to EILS, unless major engineering efforts are made. Cities in the Eastern Mediterranean with comparable long habitation histories (e.g., Jerusalem, Tiberias, Nablus, Amman) are expected to have similar geotechnical problems in their old sections and are advised to take appropriate engineering steps to reduce damage and loss of life in future earthquakes. Evaluation of historical earthquake magnitudes based on reported local-damage may, however, lead to overestimated magnitudes where the damaged sites are built on anthropogenic talus (a common setting in the vicinity of the Dead Sea Transform).