Investigation of soil structure in Uzungöl settlement area by Shallow Seismic Methods

Abstract

This study was performed to relase the soil structure of Uzungöl district of Trabzoncity, a vocational area, where had been formed by a historical landslide and lakedeposits and to evaluate its geotechnical characters by using seismic methods whichare noninvasive, rapidly applicable and provide substantial information about thestructure of investigated ground in a short time. For this purpose, seismic refraction,active-passive surface waves and seismic reflections in 16 profiles were gathered onfour sub-areas and and evaluated by current favorable numerical methods. Although itconsiderably varies between profiles, the depth of basement, depositional base ofdeposits, was averagely obtained as 13.5-15m at upper elevation and 25-50m at lowerelevation of the study area. Dynamic elastic parameters and average shear wavevelocity of the upper 30m (VS30) of soil in the area were calculated. The soilclassification of study area was interpreted as locally Z1 and Z2 class for TEC, B and Cclass for EC-8 code, C and D class for NERHP. According to VS30 (394-530m/s), groundamplification and predominant vibration period of the study area are respectivelyobtained as 1.5-2.1 and 0.23-0.30sec. On the other hand, all deposits are characterizedby stiffness-solid soil, excluding arable soil from surface to a few meters depth. Inaddition, the first meters of bedrock shows weathered character, but deeper parts arevery compact and hard. Therefore, a scientific infrastructure has been formed to carryout the engineering projects to be planned for Uzungöl settletment safely and withoutdamaging the environment.