Internationa 
# PESREF 
  
Figure 6. A three-dimensional model of the alluvium thickness 
of the studied area 
Using this theoretical information, Vay obtained from the 
locations undergoing SCPT applications and values of the 
thickness of the alluvium, the fundamental vibration period of 
the ground of the study area was determined and mapped 
accordingly (Figure 7). 
  
  
4 " "t 
rd e und res ES Tr ms Ire i IL 
Cist Heckckos EU rer BRE To 1h Eat ZH ne 
BENE tra rima rra d pria 
cts 4 rem Hr es Fats t d EE Prae 
es Mem abwiteg HE Irüis ip gp La inis 
Figure 7. Fundamental vibration period map of the ground of 
the studied area (Ty) 
The minimum value of the fundamental period of the ground 
was 0.18 and the maximum value was 0.61 for the 32 different 
locations in the studied area. All the data were determined to 
agree with the normal distribution function and the mean level 
was 0.39, which was in agreement with the characteristics of an 
alluvial ground (Figure 8). 
| Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Vol XXXV, Part B7. Istanbul 2004 
  
  
  
  
  
  
  
  
  
  
  
  
  
  
T 
10 
84 p 
6 + 
44 dq T E777 
9 2 
z vp : Std. Dev = ‚11 
i EE : PCI Mean = ‚39 
t 0 N = 32,00 
  
  
  
  
Figure 8. Frequency histogram of T, values determined for the 
studied area 
5. ANALYSIS OF EARTHQUAKE RISKS ACCORDING 
TO SITE PERIOD FOR THE STUDIED AREA 
When the fundamental vibration period of the ground is equal 
to that of peculiar vibration period of the building, which is 
called resonance, seismic burdens that have an impact on the 
structure pose high risks and thus increase the possibility of 
damage to and vulnerability of the structure (Akkargan, S. and 
Özcep, F., 2000). Each structure and building on the earth has 
its own type of contraction materials for construction and 
different numbers of storeys and a peculiar characteristic site 
period frequency depending on many parameters (Saglam, H., 
2003). 
Concrete buildings were determined to form the highest number 
of the structures in the study area. Characteristic site periods for 
different storeys of the structures to be constructed in the 
disaster areas according to the “Equal Earthquake Method" 
issued on 1998 in Building Code are determined using the 
following equation ; 
I 
T, 20054H , ^ Q) 
T, 
where — Hy- Building Story x 3 
Regarding the structure-ground relationship, the peculiar 
characteristic site period of the superstructure was calculated 
with the equation of (2) so that a risk analysis could be made in 
terms of resonance. 
Based on the fundamental vibration period of the ground in the 
study area, four possibilities were determined for the structures 
in the study area to experience resonance (Table 1). 
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| i bY LT FEET 1 
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