Numerical modeling of seismic microzoning for Apsheron peninsula of Azerbaijan

Category Tectonic & Seismotectonic
Group GSI.IR
Location 4th internetional Conference on Seismology
Holding Date 11 March 2008
     The basic point in seismic microzoning study is to provide strong seismic motions over the areas and vulnerability to destructive earthquakes. Seismic microzoning maps allow conducting estimations of the seismic hazard, evaluating probable damages to infrastructures due to earthquake disasters. For carrying out these aspects successfully, it is fundamentally necessary to determine careful investigation of a researching area in tevms of not only seismicity, but also surface and base geology, geomorphology, topography and soil conditions. In this study, ApsheronPeninsula, including BakuCity-the capital of AzerbaijanRepublic was researched by seismicity, target earthquakes, attenuation, . soil and rock properties, geological crossection, the boring data of measured shear-wave velocity, ground modeling, amplifications and base rock and surface ground motions. The process of research was done using visualization techniques applying SHAKE program (Japanese version) and MapInfo Professional 4.5 (USA). Defming an amplification factor of the each geological unit through shear wave velocity was important and necessary in order to apply attenuation formula for calculating Peak Ground Acceleration (PGA) at base rock, because calculating PGA at surface seismic motion was proceeded by multiplication PGA at the base rock with amplification parameter of each surface layers all the way through 3800 meters. The result of data processing, modeling, mapping, interpreting made it possible to identify certain regularities in the attenuation of the earthquake intensities, to classify soil conditions, to determine peak ground acceleration at base rock and ground surface caused by target earthquakes. In this approach, Quaternary type of deposits were examined in detail, because for the areas with living objects, villages, small towns Quaternary outcrops represent the fact of risk with increasing PGA value at the surface. In this paper, there was an attempt to apply the relationship between PGA values with MSK scale of seismic intensity. Finally, seismic microzoning numerical models of PGA value was drawn which gives the possibility for estimating a level of a seismic motion, the visual seismic intensity picture of the researched area for countermeasures plans, for future assessment and for mitigating the level of future disasters.

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