t - Süleyman Demirel Üniversitesi

ABSTRACT
Ph.D. Thesis
SHEAR WAVE VELOCITY (Vs30) MAPPING OF İZMİR-MENEMEN
SETTLEMENT AREA BY USING SURFACE WAVE INVERSION
Bekir TÜZEL
Süleyman Demirel University
Graduate School of Applied and Natural Sciences
Department of Geological Engineering
Supervisor: Prof. Dr. Ali BİLGİN
The average shear-wave velocity (Vs30) of the top 30 m of the Earth is specified as the
most important parameter that needs to be determined for the evaluation of dynamic
response of soil according to the earthquake resistant design codes of Turkey and
other countries. Measurement or estimation of the shear-velocity profile of sediments
overlying geological basement is a vital part of site zonation studies for earthquake
hazard prediction, and more generally for geotechnical studies. Research studies
reveal that Vs is the most effective parameter for one dimensional (1-D) space.
Classical boring method to obtain this parameter is an expensive method that causes
damage to the environment. Near surface S wave velocity structure can be estimated
from the dispersion curves derived from the Rayleigh waves. For this aim, several
methods based on surface waves inversion analysis have been developed. In spite of
conventional methods, Surface waves analysis methods are important for being nonintrusive,
cost effective and less time consuming. Their use is becoming more popular
worldwide.
In the scope of this thesis study; by using the surface waves inversion analysis
methods of Multichannel Analysis of Surface Waves (MASW) and Spatial
Autocorrelation (SPAC), shear wave velocity (Vs30) maps of the existing settlement
fields as well as the future settlement fields of Menemen district, which is in the main
developing axis of İzmir province are developed. Soil predominant frequency and soil
amplification values have been also mapped for the same region using H/V
(Nakamura) method. Besides, by comparing the information obtained using surface
waves analysis method with the boring information, reliability of the surface waves
analysis method in its ability to resolve layering and the capability of penetration
depth was analyzed. Moreover, in the scope of this study, by comparing the 1-D earth
model obtained using surface waves analysis method and the frequency spectra of
micro-tremor measurements, relationship between the fundamental soil frequency and
the bedrock depth for the investigated region is developed.
Key Words: Surface waves analysis, shear-wave selocity (Vs30), soil predominant
frequency and soil amplification
2009, 230 pages
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