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International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Vol XXXV, Part B7. Istanbul 2004
High Normal Low
T [s] Reso Reso Reso No Resonance
nance [1] nance [2] | nance [3]
Story Story Story Story
0.58 9 8 10 7 6 5 4 1.3 1.24 il
0.56 8 9 7 10 6 8 3 |-3-1.2 151
0.54 8 9 7 10 6 5 4.0302} 1
0.52 7 8 9 6 10 5 4.4:3.1.2 nl
0.50 7 8 9 6 10 3 4.13 L2 | 4
0.48 6 7 8 5 9 io 14 13]2. ]
0.46 6 7 8 5 9 4 10 312].
0.44 6 7 5 8 4 i059 3.25 I
0.42 5 6 8 7 4 10 19 13!/2[|
0.40 5 6 7 4 8 3 10 | 9 21:
Table 1. Possibilities of the structures to experience resonance
depending on the number of their storeys
6. CONCLUSION
Analysing the map of Ty, which was drawn up using T; values
determined for the study area with the applications of SCPT,
revealed that the fundamental vibration period of the ground
varied between 0.18 and 0.61. The most striking feature of the
study area was that the fundamental vibration period of the
ground decreased towards the northern east and southern east
parts of the study area through which the Porsuk River flows
with an east west oriented course. In parts with high elevations,
the values of T; in the study area varied due to such geological
features as rock and presence of old alluvium. The fact that the
To value was as low as 0.20 as a result of 18" and 28"
applications seems to indicate that the ground is hard in this
part.
It is known that, there is an alluvial ground in the SCPT
application points numbered 6.13,16,22,25.27.30 and 32
(Ayday, C. et all., 2001). There was an agreement between the
high values of Ty, varying between 0.40-0.61, and the profile of
the ground.
Map of fundamental vibration period suggests that, buildings
with 5 and 6 storeys constructed on alluvial grounds in the
study area are likely to experience resonance. Using Chart 1,
resonance-risk values were determined and mapped in
consideration of the number of storeys of the buildings and the
fundamental vibration period of the ground in the study area
(Figure 9).
Figure 9. Map of resonance-risk values in terms of structure-
risk of the studied area
1141
When the distribution of resonance-risk values according to the
districts in the study area was analysed, the number of the
buildings likely to experience resonance was 63, which
accounts for the 5.4 % of all the buildings investigated. The
number of the buildings with little risk of resonance was 849,
which accounts for 73 % of the buildings in the study area
(Table 2).
Riskl | Risk2 | Risk3 | Risk4 | Toplam
Haciseyit 18 14 9 208 249
Hayriye 1 5 27 122 155
ihsaniye 9 9 6 144 138
Hacialibey 15 23 10 150 198
Cumhuriy 20 55 89 255 419
e
Toplam 63 106 141 849 1159
(%) 5.4 0.1 12.2 73.3 100
Table 2. Distribution of resonance-risk values in the study area
according to districts
Buildings with 1,2 and 3 storeys were categorized as the fourth
group as they were the ones with the least risk. They account
for 73.3 % of all the buildings in the study area, but they
accommodate only 25.5 % of the inhabitants residing there. On
the other hand, buildings with 7, 8 and 9 storeys were
categorized as the 1 group as they were the ones with the
highest risk. They account for only 5.4 % of all the buildings in
the study area, but they accommodate 51.9 % of the inhabitants
of the study area. Therefore, we suggest that the risk should not
be determined according to the number of the buildings. On the
contrary, it should be determined according to the number of
the storeys of the buildings and the number of the inhabitants
occupying these buildings (Figure 10).
PEKI Rkk2 PEK3 REk 4
DET
Figure 10. Percentage values of resonance-risk in the studied
area