Integrated use of geological, geophysical and geotechnical data in microzonation studies (Northern Adana case)

Main purpose of this study is to provide the integrated use of geological, geophysical and geotechnical data in context of microzonation in Northern Adana (Turkey). Study area has morphologically variable topography. Geologically, the investigation area is occupied by Handere Formation and caliche and alluvial units. Shear wave velocity (Vs30) of these formations are between 238 and 742 m/s values. In the study area, Handere formation, caliche and alluvial units are generally composed of fine grained soils such as CH, CL, ML types and coarse grained soils with fine grains such as SM, SC, GC, GM types and coarse grained soils such as GW, GP types. Handere formation is unstable inclined areas.For the study area, the probabilistic seismic hazard analysis was determined by using Poisson probabilistic approach. In the second phase of seismic hazard analysis, by using deterministic seismic hazard analysis, the magnitudes were estimated by the several rapture models of East Anatolian and Ecemiş Fault Zones in Adana region. By using both analysis (deterministic and probabilistic), magnitude of design earthquake were estimated for several distances by several attenuation relations. In the second phase of the study, soil amplification factors and site characteristic periods were determined and estimated by geophysical (seismic) measurements for the study area. From shear and compressional wave velocities, several soil properties were determined and presented. Geotechnical test data from boreholes and laboratory measurements were evaluated with geological and geophysical data. Soil amplification values estimated by empirical relationships by shear wave velocities. Seismic slope stability analysis was made for the study area.Seismic microzonation can be considered as the preliminary phase of earthquake risk mitigation studies. It requires multi-disciplinary contributions as well as comprehensive understanding of the effects of earthquake generated ground motions on man made structures. In general, three zones are defined for every earthquake effect (such as soil amplification, liquefaction and slope instability). In the study area, each earthquake effect (soil amplification, liquefaction and slope instability) were mapped. The final map of microzonaton was prepared in tree zones (A: High, B: Medium and C: Low).In the microzonation map of the study area there is the high hazard for landslides/slope stability.