An IDW-based GIS application for assessment of geotechnical characterization in Erzincan, Turkey

Abstract

Preparing maps for geotechnical characterization in earthquake-prone areas is significantly important for decision-makers and local-planners in order to reduce loss of lives. This study presents a series of maps for Erzincan city, which is mostly located in a deep alluvial basin in nearby area of North Anatolian Fault Zone (NAFZ). The maps for addressing certain physical properties of soils Atterberg’s limits, classification, standard penetration test (SPT), shear wave velocity (Vs), and primary wave velocity (Vp) findings in the region have been prepared using field-based methods and geotechnical data of 92 available boreholes in Erzincan. The geological units underlying the city is consisted of various amounts of silt, clay, gravel, and sand, while it is predominantly classified as either low plastic clay (CL) or medium plastic silt (SM). Liquid limit (LL) and plastic limit (PL) values varied between 28–45% and 5–24%, respectively. The lowest SPT blow counts were found to be in southern part of the Erzincan city. The northern parts with the highest Vs values (higher than 1000 m/s) have been determined as very dense cohesionless soils. Furthermore, a correlation performed via NN between the unconfined compression testing results and dynamic elastic modulus from field studies yielded a very high correlation coefficient (R2=0.97). Evidently, the GIS maps produced by inverse distance weighting (IDW) method could be efficiently used by engineers as well as researchers for the purpose of land-use planning and urban development in earthquake-prone regions.