A microzonation study for coastal zone land-use planning: Kandira, Izmit (Turkey), case study

Abstract

Determination of the safe and risky areas in terms of soil properties is highly important in the planning of residential areas when considering natural hazard risks such as earthquake, landslide, etc. It is necessary to perform detailed soil investigations for safe constructions in most new settlement areas and also old cities which have a suitable topography. In this study, soil characteristics of coastal zone in Kandira district were investigated by in-situ and field survey data in order to prepare microzonation maps of the study area. The study area is covered by quaternary aged alluvium and upper cretaceous aged micritic limestones and located on the northern part of Izmit province and within a second-degree earthquake zone of Turkey. Determined Vs30 values and the soil amplifications are ranged from 77.8 m/s to 367.9 m/s and 1.67 to 4.12, respectively in the study area and SPT blow count values are less than 10 in the alluvium units. The obtained results in this study indicate that the west and east parts of the study area have better soil features. Considering the earthquake hazard of the study area, liquefaction analyses were performed and it was determined that some local areas in the alluvium have liquefaction risk.