INVESTIGATIONS WITH GEOPHYSICAL METHODS OF SOIL ENGINEERING PROBLEMS

First Parameters to associated with earthquake damage mitigation and vulnerability are active tectonics regime (as North Anatolian Fault Zone:NAFZ and Aegaen- Horst and graben normal faults system) and the proximity of fault zone, and thickness of soft soil and the quanlity of engineering structures. Before possible earthquakes occurs these sites, researchers try to understand degree of hazard or risk and thus some investigations performed interested sites. This can be briefly called the microzation study. We studied two different sites for this investigation. First, Dikili is located in the northern part of Izmir and second, Bursa is located in the southern part of Marmara Sea. Them of both have active tectonics regime with different structural model and stress loading and recorded many historical and instrumental earthquakes of both places.

Aim of this study, which possible soil problems may occur these sites to any possible earthquake. In the context, 121 and 75 profiles of multi-channel analysis of surface waves (MASW-REMI) measurements performed to determine the soil properties in Dikili and Bursa, respectively and the results of them have been tried to explained solution of soil problems by using different approaches and techniques. In order to achieve the shear wave velocity values to best characteristics of the geological structure collected the surface wave data. These records were evaluated individually for each profile, and measurement results were compared/combined for the same profiles and an average Vs30 value obtained for the profiles.

Possible soil problems solved or calculated with collected drilling data, together in study areas Potential soil engineering problems (liquefaction, soil settlement induced to liquefaction ground bearing capacity, soil amplification and soil rezonans period) analyzed and mapped by using Geographical Information Systems.