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Identification of liquefaction failures based on aerial images

Abstract:

One helpful tool to detect damages after an earthquake in cities is images analysis. Aerial images can be taken before and after an earthquake. By comparing both images it is possible to analyze the damages that are caused by the earthquake event. It is important to find out as soon as possible where the biggest damage to structures and lifelines has happened in order to start immediate help and reduce further risk. Especially in urban areas the analysis of the damage defines the remedial action. Certain damages can be referred clearly to the soil such as large ground deformations, ground failures or lateral spreading. One of the reasons is soil liquefaction. Based on soil-structure interaction, liquefaction can cause severe damage e.g. tilting and sinking of buildings next to sand volcanoes. Aerial photogrammetry, satellite images and SAR laser profiling data are utilized to supply many opportunities for determination of ground displacement and liquefaction failures depending on resolution and measuring accuracy. In this paper, first soil liquefaction and photogrammetric measures are explained, second, the process of analyzing the images with focus on building damage associated with liquefaction failure is described and third the knowledge is applied on a case study in Adapazari after the 1999 Kocaeli earthquake. Especially in the old city centre numerous liquefaction events were reported. Aerial images are available before and after the earthquake as well as soil information based on borings.

Authors:

Buchheister, Juliane and Rezaeian, Mehdi

Index Terms:

liquefaction; soil-structure interaction; aerial image; damage case study; photogrammetry; SoilGroup; Buchheister, Juliane; Rezaeian, Mehdi

Further Information:

Date published: 2008