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T.R. ISTANBUL METROPOLITAN MUNICIPALTY
DEPARTMENT OF EARTHQUAKE RISK MANAGEMENT AND URBAN DEVELOPMENT DIRECTORATE OF EARTHQUAKE AND GROUND ANALYSIS
PRODUCTION OF MICROZONATION REPORT AND MAPS
EUROPEAN SIDE (SOUTH)
GEOLOGICAL – GEOTECHNICAL STUDY REPORT ACCORDING TO THE CONSTRUCTION PLANS AS A RESULT OF SETTLEMENT
PURPOSED MICROZONATION WORKS
FINAL REPORT (SUMMARY REPORT)
OCTOBER 2007 ISTANBUL
OYO INTERNATIONAL CORPORATION
TABLE OF CONTENTS
1 OBJECTIVE AND SCOPE …………………………………………………………… 1 1.1 Objective of the Work ……………………………..………………………………… 1 1.2 Scope of the Work …………………………………………………………………… 1
1.3 Work Organization …………………………………………………………….......... 2
2 INTRODUCTION OF THE WORK AREA AND WORKING METHODS………… 3 2.1 Location of the Work Area ………………………………………………………… 3
2.2 Database, Mapping and Working Methods …………………………………………. 5 2.3 Summary of the Work ..……………………………………………………………. 6
3 GEOGRAPHICAL LOCATION AND GEOMORPHOLOGY…………………….. 7
3.1 Geographical Location ……………………………………………………….......... 7 3.2 Geomorphology ……………………………………………………..….................. 7
4 CONSTRUCTION PLAN ……………………………………….……………….…… 9
5 GEOLOGY…………………………………………………………….…………..…... 10 5.1 General Geology ………………………..……........................................................... 10 5.2 Geology of the Project Area……................................................................................ 13
5.3 Structural Geology ……………….............................................................................. 15 5.4 Historical Geology ……………….............................................................................. 16
6 GEOLOGICAL WORKS, GEOPHYSICAL MEASUREMENTS AND
IN-SITU TESTS …………………………………………………………………….… 17 6.1 Geological Works ……………………………………………………….………….. 17 6.2 Geophysical Measurements…………………………………………………………. 17
6.3 Local Soil Characteristics ……………………………………………....................... 18
7 LABORATORY TESTS ………………………………………………………………. 24 7.1 Contents of Laboratory Tests ………………………………………………………… 24 7.2 Results of Laboratory Tests …………………………………………………………. 24
8 HAZARD ANALYSIS AND MAPPING ……………………………………………… 26 8.1 Earthquake Hazard Analysis ………………………………………………………… 26 8.2 Surface Ground Motion Analysis……………………………………………….......... 37
8.3 Liquefaction Hazard Analysis……………………………………………………….. 48
8.4 Mass Movements (Slope Instability)………………………………………………... 53
9 WATER STATUS ……………………………………………………………………… 58
9.1 Groundwater Levels …………………………………..…………………................... 58
9.2 Flooding Hazard Analysis ………………………..………………….......................... 61 9.3 Tsunami Hazard Analysis …......…………………………..…………………............. 67
10 ASSESSMENT OF SUITABILITY FOR SETTLEMENT ………………….…….... 78 10.1 Technical and Legal Criteria of the Evaluation …………….………………….……. 78 10.2 Evaluation of Hazards in Terms of Settlement Suitability………………….……….. 78
10.3 Suitable Areas (UA) …………………………………………………..……….......... 78 10.4 Precautionary Areas (ÖA) …………………………………………………………… 79
10.5 Unsuitable Areas (UOA) …………………………………………………………….. 82
11 RESULTS AND SUGGESTIONS ………………….…………………………….….... 84
1
1 OBJECTIVE AND SCOPE
This Report describes the summary of contents, methods and results of “PRODUCTION OF
MICROZONATION REPORT AND MAPS – EUROPEAN SIDE (SOUTH)” (hereinafter referred to as “the
Work”), prepared by OYO International Corporation (OIC), and submitted to Istanbul Metropolitan
Municipality (IMM).
1.1 Objective of the Work
The objective of the Work is to identify separate areas which have different potentials for hazardous
earthquake effects and to produce the seismic microzonation report and maps which can serve as the basis for
“hazard-related land use management and city planning” within the boundary of Istanbul Metropolitan
Municipality. In order to assess these earthquake effects, detailed geological, geophysical, geotechnical, and
seismological investigations and study were conducted.
1.2 Scope of the Work
The flow of whole Work is shown in Fig. 1.2.1.
Fig. 1.2.1 Flow of the Work
(1) Planning and Organization for the Work
(2) Site Investigations and Data Collections
(3) Data Input and Evaluation
(4) Data Analysis and Processing
(5) Microzonation Mapping and Reporting
2
1.3 Work Organization The Work organization is shown in Fig. 1.3.1.
Fig. 1.3.1 Work organization
Istanbul Metropolitan Municipality
Department of
Earthquake and Soil Research
Technical
Committee
OYO International
Corporation
Project Manager
Geological
and
Geotechnical
Work group
Seismological
and
Geophysical
Work Group
City Planning,
Geomorphology,
and GIS
Work Group
Microzonation
Evaluation
Work Group
Project Team
3
2 INTRODUNTION OF THE WORK AREA AND WORKING METHODS
2.1 Location of the Work Area The location of the Work area is shown in Fig. 2.1.1.
Fig. 2.1.1 Location of the Work area
Fig. 2.1.1 Location of the Work area
The Work area, shown in Fig. 2.1.2, is the land portion surrounded with the following coordinates:
1) X: 388,598.72 Y: 4,547,051.31 2) X: 388,430.19 Y: 4,535,945.17
3) X: 407,375.58 Y: 4,535,681.75 4) X: 415,860.39 Y: 4,541,134.16
5) X: 415,892.19 Y: 4,543,910.66 6) X: 411,720.15 Y: 4,546,736.56
The total area is approximately 182 km2. The Work period is between 18.01.2006 – 19.10.2007 and this final report has been prepared in October
2007.
4
Fig. 2.1.2 Work area grid map (250 x 250 m. European Side (South), İstanbul)
Proje İçi GridlerProje Dışı Gridler
Proje Alanı
5
2.2 Database, Mapping and Work Methods Data and maps are prepared in ArcInfo1 environment, after an agreement with the Municipality.
National geodetic coordinate systems are used to produce data and maps. 1/1000 scale DGN files of
year 1999 are mainly used as base map. 1/5000 scale DGN and GEO-TIFF files of year 2005 are
used as assistant base map. Geological legends are based on MTA’s geological mapping standard,
and updated for Istanbul based on the comments of control engineers, professors and other high
engineers. The datum of “1/1000 scale DGN files of year 1999“ is “European Datum 1950”. The datum is
pre-defined by ArcGIS 9.1.
Major database systems developed in this project are listed in Table 2.2.1.
Table 2.2.1 Major database systems
Name Path Description
Borehole Log I:/Project2006/
drilling data/
log excel/
This is a borehole log system and data, including systems
to draw the N chart and lithology in borehole logs in
Excel format.
GeoDB I:/Project2006/
GeoDB
This is a system to combine the data files of field survey
result into one GIS database, including systems to import
borehole logs, laboratory test result, CPT field test result,
ground water monitoring result, PS logging result, ReMi
field survey result, array microtremor field survey result,
resistivity field survey result. The system also include
the control system of elevation value of field survey
locations with DEM data, and the liquefaction potential
calculation system.
Building Extraction I:/Project2006/
Tools
This is a system to extract building boundary polyline
from all 1/5000 base maps of year 2005, and convert to
building polygon. The output of this system is used for
Tsunami Simulation.
1/1000 base map file
conversion
I:/Project2006/
Tools
This is a system to convert all 3D-Spline of DGN files
into polyline, and then convert into shapefiles. Both of
Microstation/J 7.1J BASIC environment and ArcGIS 9.1
VBA are used for system development.
PDF Export I:/Project2006/
Tools
This is a system to shift map extent and export PDF files.
1 Version 9.1
6
2.3 Summary of the Work Total amount of 2,830 normal drillings with 30m depth, 27 deep drillings, 764 liquefaction
drillings, 608 landslide drillings, 100 drillings with differant depths to determine baserock depth
and thickness of some formations and also 35 drillings to determine some structural features like
faults and alluvium thickness as a total number of 4,364 mechanical drillings were conducted in
2,912 grids (250x250) within the context of project. Total drilling depth was 125,578.90 m. Beside
SPT tests which were conducted in the site, 636 CPT tests were also conducted.
Total 2,762 Seismic Refraction – ReMi measurements, 2,625 Electric Resistivity measurements,
201 PS Logging tests, Array Microtremor measurement in 30 points and 20km lenght Seismic
Reflection measurement were conducted within the context of geophysical studies.
These studies that conducted in field were supported with laborary tests and complied in office
work with grouping recent and possible hazards by conducting necessery analiysis.
Consequently, Microzonation maps were produced regarding to the studies which were
mentioned above and settlement suitability map were created from these maps.
7
3 GEOGRAPHICAL LOCATION AND GEOMORPHOLOGY
3.1 Geographical Location In the general view of Istanbul area, the Bosphorus, a narrow straight, links the Marmara Sea to the Black
Sea, and divides Istanbul into two main parts: European side and Asian side. The European side of Istanbul is
split in historical areas and modern areas by the Golden Horn, a narrow channel off the Bosphorus.
The Work Area includes west part of the Golden Horn and it is bounded by the Golden Horn and the
Marmara Sea enterance of the Bosphorus in east, the Marmara Sea in south, east slopes of Yakuplu district
(west slopes of Haramidere) in west and TEM highway (South) in north.
3.2 Geomorphology Fig. 3.2.1 shows the topography in the project area. The project area, facing the Marmara Sea to south,
lays east and west. Lots of hills divided by valleys along north to south are observed.
The Küçükçekmece Lake divides the project area into the west part and east-middle parts. There are
several rivers such as Harami Dere, Karagos Deresi, Hasan Deresi, Ayamama Deresi, Tavukçu Deresi, Çinçin
Deresi, Terazidere, which run from north to south.
There are also several major hills in Mabarli, Avcilar, west side of Bakirköy, west side of Bağcılar, west
side of Bahçelievler, east side of Bakırköy, south side of Esenler, east side of Güngören, Zeytinburnu south
side of Fatih, north side of Fatih, Eminönü, etc. These hills extend from south to North.
North-east part of the work area is bounded by the Golden Horn. One of the most important topographic
features is that the upper plains of hills gently incline toward the Marmara Sea to south. These flat plains on
hills, covered by the Bakırköy limestone as mentioned later, are presumably the depositional surface of this
layer. The horizontally formed plains became inclined to south in consequence of the change of sea water
level and the structural movements. Through this process, valleys were generated along rivers flowing from
north to south.
8
Fig. 3.2.1 Topography in the project area
9
4 CONSTRUCTION PLAN
The Work area includes whole parts of Bakırköy, Bahçelievler, Güngören, Zeytinburnu, Fatih, Eminönü,
Avcılar districts and some parts of B.Çekmece, K.Çekmece, Bağcılar, Esenler, Bayrampaşa, Eyüp and
Esenyürt districts. 1/5000 scale Main City Construction plan prepared by the Metropolitan Municipality is
available in the Work area and 1/1000 scale Implemantation Construction Plan was prepared by district
municipalities. Reclamation Construction Plans (North part of K.Cekmece Lake..etc.) were prepared inside of
some district boundries. Also, in coasts of Bakırköy and Zeytinburnu districts along the Marmara Sea, the
Tourism Central Construction Plans are available under the authorization of the Department of Tourism.
1/5000 scale Main City Construction Plan prepared by Metropolitan Municipality is available in the Work
Area and 1/1000 scale Implemantation Construction Plans and also Reclamation Construction Plans of some
districts in the boundries of Work Area. Tourism Central Plans is available for coastal parts of Bakırköy and
Zeytinburnu districts.
Geological Studies According to the Existing Plan are studies which were generally prepared after 1999
Marmara Earthquake. “Geology and Suitability for Settlement” study which is basis for 1/5000 scale Main
City Construction Plan prepared by Metropolitan Municipality is available for every region in work area.
Furthermore, “Geology and Suitability for Settlement” studies which are basis for 1/1000 or 1/2000 scale
Implementation Construction Plan prepared by every district municipalities are also available.
Unsuitable areas for settlement in existing studies regarding to the districts:
In the boundries of Avcılar; area which was effected by the Balaban Landslide that occured in sea-facing
slopes of Ambarlı ward (this place was declared as Disaster Effected Area according to number 9109
Cabinet Decision on 28/06/2005), slope of Firüzköy ward facing K.Cekmece Lake, Menekse Landslide inside
the boundries of Bakirkoy district and Halkalı Junk Yard inside the Halkalı ward in K.Çekmece district are
unsuitable areas because of their characteristic features. Beside these areas, coastal areas with fillings and
recent fillings in highway route condemnation boundaries are suggested as unsuitable areas for settlement.
10
5 GEOLOGY
5.1 General Geology Fig. 5.1.1 shows the general stratigraphy for this project. The only Paleozoic stratum found in the project
area is the Trakya Formation. This bed is so different from the upper beds in lithology that it can be identified
without difficulty.
The Ceylan Formation can be also easily identified because it is different from the lower Trakya Formation
and the upper Gürpınar Member or the Güngören Member in facies.
Although the Soğucak Member is assigned to the lower bed of the Ceylan Formation according to the IBB
Geological Map, it was included in the Ceylan Formation for this project, because the limestone, which
characterizes the Soğucak Member, is interlayered with the Ceylan Formation and is regarded as heteropic
facies.
According to the IBB Geological Map, the Danışmen Formation (including the Gürpınar Member) mainly
consisting of clay is extensively distributed on hill areas in the west side of the Büyükçekmece Lake, the west
to the project area. The Çukurçeşme Formation mainly consisting of gravel overlies the Danışmen Formation
in the north of the hill areas.
The Güngören Member mainly consisting of clay and the upper Bakırköy Member consisting of limestone
or marl are distributed only along the coastal area of the Marmara Sea in the west part of the Büyükçekmece
Lake. These two members are presumably one continuous bed deposited in a basin smaller than that where the
Danışmen Formation and the Çukurçeşme Formation were deposited. It is reasonable that both of the
Güngören Member and the Bakırköy Member are included in the Çekmece Formation because of no big
difference in the depositional environment and transitional or interlayered border of the bed.
According to the IBB Geological Map, the Kuşdili Formation is assumed in Holocene age. This formation,
the lower bed of the Alluvium, is supposed to be characterized by considerably containing humus in black
color or fossils. This formation could not be distinguished from the Alluvium in this project.
As a result of the above consideration, the stratigraphy was the same as that in the IBB Geological Map
except the Kuşdili Formation and the Soğucak Member. Regarding the Holocene beds, ‘Top soil (Qbt) and
‘Beach sand (Qpk) were distinguished from the Alluvium.
Fig. 5.1.2 shows the geology in the bird’s-eye view of the project area. The stratigraphy in the geology is
shown in Fig. 5.1.3. The bird’s-eye view shows there are inclined hills overlain by limestone layers called the
Bakırköy Member in the south part (sea side) of the project area
The hillsides are overlain by clayey soils (greenish grey color) called the Güngören Member. That is, the
hill areas consist of the Güngören with the Bakırköy on the upper side.
Some parts of the eastern side of the Küçükçekmece Lake are overlain by limestone layers called the
Ceylan Formation (dark bluish color). Slopes of hills facing the Haliç in the eastern side of the project area are
overlain by the Paleozoic layer called the Trakya Formation (dark greenish color). The Ceylan or Trakya
Formation corresponds to the engineering bedrock.
11
Fig. 5.1.1 General stratigraphy
12
The bedrock is overlain by the Gürpınar Member (greenish grey color), which is observed partly at the low
elevation zones in the northern part of the project area. The Çukurçeşme Formation (green) is partly found
between the Gürpınar and the Güngören.
The Alluvial plains, where the Alluvial sediments (light grey) are distributed, are found among hills from
south to north. There is no large coastal plain. A large sand bank (2 km of length) is observed between the
Küçükçekmece Lake and the Marmara Sea.
Thick artificial fills (more than 10m of thickness) are found at coastal areas and some parts of inland areas.
The eastern coast areas were formed by the reclamation of the sea area.
Fig. 5.1.3 Stratigraphy in geology
Fig. 5.1.2 Geology in bird’s-eye view of the project area
13
5.2 Geology of the Project Area Fig. 5.2.1 shows the geology in the project area. Formations and members found in the project area are as
follows in ascending order.
(a) Trakya Formation
(Palaeozoic, sandstone and others )
(b) Ceylan Formation
(Eocene, Limestone and others)
(c) Gürpınar Member (belonging to Danışmen Formation)
Oligocene - Miocene, sand, clay, clay stone, and others.
(d) Çukurçeşme Formation
Miocene, Gravel and sand.
(e) Güngören Member (belonging to Çekmece Formation)
Miocene, mainly clay.
(f) Bakırköy Member (belonging to Çekmece Formation)
Miocene, limestone marl, and others
(g) Alluvium Deposit and others
Mainly Holocene, clay, sand, beach sand, top soil
(h) Recent Fillings
Fig. 5.2.1 Geology of the project area
14
(1) Trakya Formation
The Trakya Formation is a sedimentary rock in the Paleozoic Carboniferous. The layer mainly consists of
sand stone, including shale in most cases. A kind of pyroclastic rocks such as tuff is rarely included. These
rocks are called “Graywacke” all together. The intact rock is extremely hard, well consolidated and influenced
by the metamorphism.
(2) Ceylan Formation
The Ceylan Formation is a sedimentary rock in the Paleogene and Eocene. The Ceylan Formation consists
of limestone, calcareous sandstone, claystone, sandstone, or tuff. Some parts of this formation are sometimes
called the Soğcak Member, which consists of only hard limestone not including other rocks.
(3) Gürpınar Member (belonging to the Danışmen Formation)
The Gürpınar Member belongs to the upper part of the Danışmen Formation. The lower part is of
Oligocene age, while the upper part is of Miocene age. The Gürpınar Member consists of clay or claystone
(dark green), sand or sandstone, gravel or gravelstone (dark grey), tuff (dark green), and calcareous sandstone
(grey).
(4) Çukurçeşme Formation
The Çukurçeşme Formation is a sediment of Miocene age, distributed locally in the middle to west part of
the project area. The Çukurçeşme Formation consists mainly of gravel or sand, partly of clay with gravel or
gravelstone. This formation is characterized by its reddish brown color due to oxidation. The content of gravel
is higher at the northwest area, while that of sand is higher at the southeast area.
(5) Güngören Member (belonging to Çekmece Formation)
The Güngören Member, deposited in Miocene age, is the lower part of the Çekmece Formation. The
Güngören Member consists mainly of clay and partly of sand. A part of the clay is, well consolidated,
forming claystone. It rarely contains limestone or carboniferous sandstone.
(6) Bakırköy Member (belonging to the Çekmece Formation)
The Bakırköy Member, the upper layer of the Çekmece Formation, is of the latest Miocene. The Bakırköy
limestone is characterized by its plate-like shape. Thin greenish clay is usually contained in a white limestone
layer of 5 to 20 cm in thickness. The limestone also usually contains soft white marl or sand.
(7) Alluvium, Top soil, Beach sand
The Alluvium is deposited in low lands along rivers. The Alluvium is a stratum that was deposited in
valleys created in times when the sea level was lowered. The Alluvium in the project area is mainly composed
of clay. In case the Gürpınar sand is distributed around the buried valleys, the alluvium often contains the sand
15
layers from the Gürpınar sand. The bottom of buried valleys partly contains gravel.
(8) Recent Fillings
Various fills are distributed in the project area. These fills are composed of various kind of artificial soils
such as ones for construction of factories, airport, schools, ones for construction of roads or railroads, ones
formed in the historical area, ones for reclamation of coastal areas, ones for filling the Alluvial plains, ones of
which the origin is unknown.
5.3 Structural Geology Fig. 5.3.1 shows the elevation contours of bedrocks, created based on the results of drillings (including the
deep drillings) and the array microtremor measurement. The bedrock in the east part of the project area is the
Trakya Formation, while the Ceylan Formation is for the west to middle. The upper plains of bedrock, some
50m of elevation at the north part and -200m to -300m around the coast of the Marmara Sea, generally inclines
from north to south at the east side of the Küçükçekmece Lake.
A fault (from south to north) was inferred at the Küçükçekmece Lake, because there is a big elevation gap
of bedrock between the right and left side of the Lake. Several faults at the east side of the Lake were inferred
from the results of array drillings.
Fig.5.3.1 Contours of the upper boundary of bedrock
16
Fig. 5.3.2 shows faults in the project area. A fault (from south to north) was inferred at the Küçükçekmece
Lake, because there is a big elevation gap of bedrock between the right and left side of the Lake.
At the north-west of Avcılar area, inferred fault lines are along the branch valleys. The fault was confirmed
by the trench work for one of them.
5.4 Historical Geology In the middle of Eocene, about 40 million years ago, various soils such as clay, carboniferous sand,
volcanic ash or limestome were accumulating on the Trakya Formation in the sea. These became the Ceylan
Formation.
In the middle of Oligocene, about 30 million years ago, the west part of the project area became again the
sea. The sediments consisting of sand and clay at this time are called the Gürpınar Member.
Before long, whole sea became shallower and was accumulated by gravels from rivers. These gravels are
called the Çukrçeşme Formation.
After that, in the latter of Miocene, about 10 million years ago, clayey soils were accumulating because
there was no big river around the sea. This clayey layer is the Güngören Member. When the sea became
shallower, the limestone called the Bakırköy was formed.
About 5 million years ago when the Miocene ended and the Pliocene started, the water level of the
Mediterranean Sea considerably lowered down. The Güngören clay (soft and not consolidated soils) was
overlain by the Bakırköy limestone (hard soil).
Fig. 5.3.2 Distribution of inferred faults
17
6 GEOLOGICAL WORKS, GEOPHYSICAL MEASUREMENT AND IN-SITU TESTS
6.1 Geological Works
Contents and volumes of geological works are shown Table 6.1.1
Table 6.1.1 Contents of geological works
Type of Works No. of Points Total Volume (m)
Normal drillings 2,830 86,840
Deep drillings 27 4,201
Drilling for Liquefaction Analysis 764 12,344
Drilling for Landslide Analysis 608 18,144
Extra Drillings for faults, alluvium, basement, etc. 134 4,754
CPT 636 8,769
Trench Works 2 -
6.2 Geophysical Measurements Contents and volumes of geological works are shown Table 6.2.1
Table 6.2.1 Contents of geophysical measurements
Type of Measurement No. of Points Total Volume (m)
Seismic Refraction and ReMi 2,762 -
Seismic Reflection - 20 km
PS-Logging 201 8,069
Array Microtremor 30 -
Electric Resistivity 2,625 -
18
6.3 Local Soil Characteristics
6.3.1 Local Soil Conditions P-wave velocity (Vp), S-wave velocity (Vs) and Electrical Resistivity (Rho) down to 30m depth were
obtained in most grid cells.
Fig.6.3.1.1 shows contour line maps of P-wave velocity, S-wave velocity and Resistivity at 10m depth
together with tomography and geology maps.
The followings are significant features of P-wave velocity, S-wave velocity and Resistivity in the project
area.
a) P-wave velocity distributions correspond with geology information map. For example, relatively
higher P-wave velocity zones are located the areas where Ceylan Formation or Trakya
Formation distributes. And very low P-wave velocity zones are located in Alluvium deposit
areas.
b) P-wave velocities at depth of 10m or greater are generally higher than 1.5km/s even if soft
alluvium deposits are present. This means that soil deposits are likely saturated with ground
water at depths greater than around 10m.
c) S-wave velocity distributions correspond with geology information map. For example, relatively
higher S-wave velocity zones are located the areas where Ceylan Formation or Trakya
Formation distributes. And low S-wave velocity zones are located in Alluvium deposit areas.
d) Low resistivity zones likely correspond with Alluvium deposit.
e) Higher resistivity zones correspond with the area underlying Ceylan or Trakya Formations.
19
Fig. 6.3.1.1 Contour line maps of Vp, Vs and Rho with topography and geology map
Vp(km/s)
Vs(km/s)
Rho(ohm-m
Topografya(m
20
6.3.2 Shear Wave Velocity (AVs30) The average Shear Wave velocity down to 30m depth was calculated based on the results of
PS-logging and ReMi/MASW.
Fig.6.3.2.1 shows a range of AVs30 with regard to predominant geological formations. The
predominant geological formation is here defined as the geological formation/member which
occupies the greatest part in terms of geology above 30m depth.
Fig.6.3.2.2 shows distribution map of AVs30 together with geology map of the predominant
geological formation.
Fig. 6.3.2.1 Vs30 range related to geological formations
21
Fig. 6.3.2.2 Contour line map of the AVs30 (below) together with distribution map of the predominant geological formations (above)
6.3.3 Local Soil Classes
Fig. 6.3.3.1 shows distribution maps of local soil classes in accordance with NEHRP, Euro Code
and Turkish Earthquake Code.
(1) NEHRP
The followings are major features of distribution of NEHRP classifications
1) NEHRP classifications of the project area have a range of from the class B to the class E.
There are not any grid cells which have the class A.
Contour line map of the AVs30
Distribution map of the predominant geological formations
22
2) The class E mainly distribute along the Alüvyon deposit area in the North part of Avcılar
region. In addition, the several grid cells, which are classified as the class E, are displayed in
other Alüvyon deposit areas or Yapay Dolgu areas, for example, along the Golden-hone bay,
near the Ayamama River, in the vicinity of the Halkalı railway station, the Haramidere region
etc.
3) The class D spread most project area. More than 80% of the project area is classified as the
class D.
4) The distributions of the class C correspond to Bakırköy region where limestone underlay. The
North part of Küçükçekmece region, where it is dominated by Ceylan Formation, and on hills
underlying Trakya Formation along the Golden-hone bay are also classified as the class C.
5) Number of grid cells where they are classified as the class B is only eight (8). They are found
in the North part of Küçükçekmece and on hills along the Golden Horn bay.
(2) Euro Code
The definition of the Euro classification is almost same as the definition of the NEHRP
classification. Therefore the distribution map of the Euro classification as shown in Fig.103.2.1 is
very similar to the distribution map of the NEHRP classification. In addition, the features of the
distribution map are also same as the features of the distribution map of the NEHRP classification as
described in the above paragraph.
The class E, S1 and S2 are uniqueness of the Euro code in comparison with the NEHRP code. 5
grids are classified as the class E where S-wave velocity contrast between bedrock and subsurface
soil is very high. The grids of the class E are located near Halkalı railway station and in Eminönü
region.
There are no class S1 and S2 in the project area.
(3) Turkish Earthquake Code
The following are major features of the local site classes.
1) The local site classes of the Turkish earthquake code in this project have a range of from the Z1
to the Z4. However, 84% of the project area is classified as Z3.
2) Z4 is located along the Alüvyon deposit areas, specifically in the northern part of Avcılar region,
along the Golden-Hone bay, near the Ayamama River and in the vicinity of the Halkalı Railway
Station as well as in the Haramidere region.
3) Z3 can be found in most part of the project area.
4) The Z2 classes are mainly found in Bakırköy, Ceylan and Trakya Formation areas.
5) The Z1 classes are located in the northern part of Küçükçekmece and in the hills along the
Golden-Hone bay.
6) In the Eminönü region, there are small area which are not classified due to thick landfill along
the coastline.
23
Fig. 6.3.3.1 Distribution maps of the classifications
Turkish earthquake code
NEHRP classification
Euro earthquake code
None classified
24
7 LABORATORY TESTS
7.1 Contents of Laboratory Tests
Contents of the laboratory tests are summarized in Table 7.1.1.
Table 7.1.1 Contents of the laboratory tests
Test Type Test Name
(Standard)
Sample
Type
Measured Data
Water content
(ASTM D2216)
SPT Water contents (%)
Sieve analysis
(ASTM D422)
SPT Grain size distribution Grain size
analysis
Hydrometer Test
(ASTM D4221)
SPT Grain size distribution
(clay-silt differentiation)
Physical
Characteristics
Atterberg limits
(ASTM D4318)
SPT Liquid Limit (LL)
Plastic Limit (PL)
Plasticity Index (PI)
Uniaxial compression test
(ASTM D2166)
UD Compressive strength
(qu), Cohesion C (qu/2)
Triaxial compression test
(ASTM D2850)
UD Inherent Friction Angle
(φ)
Cohesion (c)
Consolidation test
(ASTM D2435)
UD Consolidation factor
(Mv)
Soil Strength
and
Consolidation
Swell test
(ASTM D4546)
UD Swell factor (%)
7.2 Results of Laboratory Tests The numbers of tests are shown in Table 7.2.1. The averaged soil characteristics of each formation are
shown in Table 7.2.2.
Table 7.2.1 Sample numbers of the laboratory tests
Grain Size Test
Type
Water
Content Sieve Hydrometer
Atterberg
Limits
Uniaxial
Test
Triaxial
Test
Consolid-
ation
Swell
Number of
Samples 53,938 53,938 124 46,432 1,120 462 2,315 2,315
25
Table 7.2.2 Averaged soil characteristics for each formation
Water Content
Wn(%) LL(%) PL(%) PI(%)
Clay &
Silt (%)
Sand (%)
Gravel (%)
Free Swelling
(%)
Swell Pressure (kg/cm2)
qu (kgf/cm2)
c(qu/2) (kgf/cm2)
23,8 46,5 13,2 33,3 48,41 28,34 23,27 1,407 0,076 1,71 0,85
32,2 50,3 13,0 37,3 68,15 26,24 5,98 0,969 0,058 1,38 0,69
20,8 40,4 16,7 23,6 12,20 77,83 9,78 0,905 0,055
27,2 56,6 13,4 43,2 79,58 14,31 6,11 1,501 0,083 2,14 1,07
24,1 47,1 15,2 31,9 62,78 17,98 19,25 1,531 0,071 1,56 0,78
28,9 60,6 16,0 44,5 79,21 17,78 3,06 2,223 0,112 1,96 0,98
17,8 41,3 13,5 27,8 36,59 54,20 9,21 2,007 0,112 3,27 1,64
24,6 56,1 15,7 40,4 73,57 23,41 3,07 2,228 0,132 2,53 1,27
24,7 47,3 15,3 32,0 64,67 23,94 11,38 1,283 0,048 1,83 0,91
14,6 35,5 15,3 20,2 35,18 37,70 27,11 0,689 0,038 1,82 0,91
CEYLAN
TRAKYA
BAKIRKÖY
GÜNGÖREN
ÇUKURÇEŞME
GÜRPINAR
ALLUVION
ARTIFICAL FILLING
BEACH SAND
TOP SOIL
Swell Uniaxial TestFormation Atterberg limits Grain Size Distribution
26
8 HAZARD ANALYSIS AND MAPPING
8.1 Earthquake Hazard Analysis
Fig. 8.1.1 shows the outline of this analysis.
Identification of Earthquake Sources
Active Faults Seismic Activities
Historical Earthquake Catalogue
Recent Earthquake Catalogue
Tectonic Setting Literatures
Existing Fault Maps
Fault Segmentation
Characteristic Earthquakes
Floating Earthquakes
Earthquake Source Parameters by
Active Faults
(Multi-Segment rupture (Cascade)
Model)
Earthquake Sources by
Seismic Activities
Attenuation Formula
Calculate PGA at Baserock (Vs>760m/s),
for each 250m grid in Istanbul Region
Analyze 2%, 10%, 50% exceedance in 50 years
（PGA, PGV, Sa(h=5%, T=0.2 & 1.0 sec)
De-aggregation analysis
(most effective max M, R & σfor several grid)
Extracting Earthquakes
7>M>5 as background
Earthquake Hazard Map
(whole Istanbul)
Fig. 8.1.1 Flow of Earthquake Hazard Map Generation
27
8.1.1 Analysis on active faults
8.1.1.1 Historical earthquakes and the sources faults Historical earthquakes in the Marmara Sea after 1500 A.D. can be divided into characteristic
earthquakes and floating earthquakes as shown in Fig. 8.1.1.1. The former are the earthquakes of
the magnitude around Mw≧7.0 which have the characteristic recurrence period and displacement
on the specific fault. The latter are earthquakes of the magnitude around or less than Mw=7.0 which
often occur in the interval of characteristic earthquakes.
8.1.1.2 Segmentation model analysis (1) Segmentation model
The segmentation model of the active faults in the Marmara Sea region is shown in Fig. 8.1.1.2.
The fault segments are classified into the segments related to characteristic earthquakes and
floating earthquakes. The former is subdivided into the type A and the type B. Type A is the
segment with the corresponding paleo-earthquakes data to evaluate earthquake occurrence
probability. Type B is the segment with insufficient paleo-earthquake data, though it can be
considered as characteristic.
1) Segments for type A (characteristic earthquakes)
The segments composed of Ganos (GA), Princes’ Islands (PI), Izmit (IZ), Duzce (DU) and
Mudurnu Valley (MV), corresponding to the 1509, 1668?, 1719, 1766 May, 1766 August, 1912,
1967 and 1999 August, 1999 November earthquakes are estimated for type A..
2) Segments for type B (characteristic earthquakes)
The two branched fault systems distributed along the southern edge of the Marmara Sea and on
the southern land are treated as the segments for type B. They are divided to segments from S1 to
S12. In these segments, only the 1737, the 1855, the 1953, and the 1964 earthquakes are known
after 1500 A.D. Thus, several segments ruptured only once after A.D.1500, and the most segments
have no evidence ruptured historically.
3) Segments for floating earthquakes
The normal faults in the northeastern and southern edges of the Cinarcik basin, and the central
part of the Marmara Sea are estimated as the segments for the floating earthquakes, which are
formulating the normal faults.
28
Black Sea
Sea of Marmara
Istanbul
Saros Gulf
Edremit Gulf 27°
28°
29°
30°
31°
40°
41°
0 50 100km
1509
1719
1766 Aug. May1754
1556
19121894
1999Aug. Nov.
tim
e
Characteristic earthquakes
Floating earthquakes
Fig. 8.1.1.1 Historical earthquakes in the Marmara Sea
1500
1600
1700
1800
1900
2000
29
Black Sea
Sea of MarmaraIs
tanbu
l
Saros Gulf
Edremit Gulf
27°
28°
29°
30°
31°
40°
41°
050
100km
DU
IZ
PI
YA
GA
S１
S８
S９
S10
S11
S12
S２
S３
S４
S５
S６
S７
CM
MV
Segm
ents
for
type
A e
arth
quak
es
Segm
ents
for
float
ing
ear
thqu
akes
Segm
ents
for
type
B e
arth
quak
es
Fig.
8.1
.1.2
Se
gmen
tatio
n m
odel
in th
e M
arm
ara
Sea
regi
on
30
8.1.2 Analysis on seismic activities The other seismic source to be considered is seismic activities in and around Istanbul municipality. The
data set of seismic observation by KOERI from 1900 to present including magnitude, depth and epicenter
location has been already provided. The extent of the catalogue is 26.0˚ to 31.5˚E in longitude and 40.0˚ to
42.0˚N in latitude. Aftershocks and earthquake swarms are eliminated, also magnitude uniformity is checked.
As discussed above, Mw above around 7.0 should be treated and corresponded to active faults. Then, in this
study, Mw 5 to 7 will be adopted as background sources. Fig. 8.1.2.1 shows the earthquakes with magnitude
5 to 7.
Fig. 8.1.2.1 Seismic Activity (5≦Mw<7, 1900 to 2006)
8.1.3 Attenuation Relationships Based on the comparison of the Turkish strong motion data with Western USA data and owing to the
geological and geotectonic similarity of Anatolia to California, Erdik et al. (2004) has adopted several
attenuation relationships derived from California data.
In this study, the following attenuation relationships were adopted under the guidance of board member.
The average of following three attenuation relations was adopted to calculate the Peak Ground
Acceleration (PGA) and Spectral Acceleration (Sa) at 0.2 sec and 1.0 sec.
1) Boore et al. (1997)
2) Campbell (1997)
3) Sadigh et al. (1997)
Fig. 8.1.3.1 shows the PGA comparison by three attenuation relations with distance and magnitude.
Fig. 8.1.3.2 shows the Sa(h=5%) comparison by three attenuation relations with magnitude.
31
0.001
0.01
0.1
1
1 10 100 1000Distance (km)
PG
A (g
)
Mw=7Mw=6Mw=5
0.001
0.01
0.1
1
1 10 100 1000Distance (km)
PG
A (g
)
Mw=7Mw=6Mw=5
0.001
0.01
0.1
1
1 10 100 1000Distance (km)
PG
A (g
)
Mw=7Mw=6Mw=5
a) Boore et al. (1997) b) Campbell (1997) c) Sadigh et al. (1997)
Fig. 8.1.3.1 PGA attenuation relationships for strike-slip fault at NEHRP B/C boundary
0.0001
0.001
0.01
0.1
1
0.01 0.1 1 10Period (sec)
Sa(
h=5%
) (g)
Mw=7Mw=6Mw=5
0.0001
0.001
0.01
0.1
1
0.01 0.1 1 10Period (sec)
Sa(
h=5%
) (g)
Mw=7Mw=6Mw=5
0.0001
0.001
0.01
0.1
1
0.01 0.1 1 10Period (sec)
Sa(
h=5%
) (g)
Mw=7Mw=6Mw=5
a) Boore et al. (1997) b) Campbell (1997) c) Sadigh et al. (1997)
Fig. 8.1.3.2 Spectrum accelerations for strike-slip fault at NEHRP B/C boundary (d=50km)
32
8.1.4 Probabilistic Seismic Hazard Analysis The probabilistic seismic hazard analysis (PSHA) was performed using the code made by USGS. This
program calculates seismic hazard using the standard methodology for seismic hazard analysis.
(1) Time-dependent model
Time-dependent probability calculations follow the renewal hypothesis of earthquake regeneration such
that earthquake likelihood on a seismic source is lowest just after the last event.
(2) Hazard maps
The probabilistic seismic hazard was calculated for “Cascade Model” and “No Cascade Model” of faults .
Along with these fault models those were newly established in this project (OIC Model), the existing fault
model by KOERI (KOERI Model, Erdik et al. (2004)) was also used. These three seismic hazards were
unified under the guidance of board member. The numerical conditions are summarized below.
- Ground condition: NEHRP B/C boundary (30m average shear wave velocity is 760m/sec)
- Calculated physical value: PGA, PGV, Sa(h=5%) 0.2sec and 1.0sec
- Probability: 2%, 10% and 50% probabilities of exceedance in 50 years from 2006 (2006 to 2055)
- Inherent variability of BPT model: α=0.5 (after Parsons(2004))
The results obtained for OIC Model, KOERI Model and Average of them are shown in Fig. 8.1.4.1 to Fig.
8.1.4.4. The fault traces of NAF by each Model are shown in these figures.
The calculated PGA, PGV or Sa distribution by OIC Model and KOERI Model are similar for 2% and
10% PE in 50 years, however the value for 50% PE in 50years case is significantly different. The main reason
of this difference may be attributed to the smaller segmentation of NAF and the larger probability of
occurrence of each small segments of KOERI Model comparing OIC Model.
33
28°
0'0"
E
28°
0'0"
E
28°
30'0
"E
28°
30'0
"E
29°
0'0"
E
29°
0'0"
E
29°
30'0
"E
29°
30'0
"E
30°
0'0"
E
30°
0'0"
E
41°
0'0"
N
41°
0'0"
N
41°
30'0
"N
41°
30'0
"N
No C
ascad
e*0.8
+C
ascad
e*0
.2P
GA
(g)
50
% P
E in
50yr
s
0.0
- 0.1
0.1
- 0.2
0.2
- 0.3
0.3
- 0.4
0.4
- 0.6
0.6
- 0.8
0.8
- 1.0
1.0
- 1.5
1.5
-
010
2030
405
km
S6
S7
S4
S5
S9
S8
S3
S10
28°
0'0"
E
28°
0'0"
E
28°
30'0
"E
28°
30'0
"E
29°
0'0"
E
29°
0'0"
E
29°
30'0
"E
29°
30'0
"E
30°
0'0"
E
30°
0'0"
E
41°
0'0"
N
41°
0'0"
N
41°
30'0
"N
41°
30'0
"N
KO
ER
I M
odel
PG
A(g
) 5
0% P
E in 5
0yr
s
0.0
- 0.1
0.1
- 0.2
0.2
- 0.3
0.3
- 0.4
0.4
- 0.6
0.6
- 0.8
0.8
- 1.0
1.0
- 1.5
1.5
-
010
2030
405
km
30°
0'0"
E
30°
0'0"
E
29°
30'0
"E
29°
30'0
"E
29°
0'0"
E
29°
0'0"
E
28°
30'0
"E
28°
30'0
"E
28°
0'0"
E
28°
0'0"
E
41°
30'0
"N
41°
30'0
"N
41°
0'0"
N
41°
0'0"
N
OY
O+K
OER
IP
GA
(g)
50% P
E in 5
0 y
rs
0.0
- 0.1
0.1
- 0.2
0.2
- 0.3
0.3
- 0.4
0.4
- 0.6
0.6
- 0.8
0.8
- 1.0
1.0
- 1.5
1.5
-
010
2030
405
km
PGA
map
for 5
0% P
E in
50
year
s
28°
0'0"
E
28°
0'0"
E
28°
30'0
"E
28°
30'0
"E
29°
0'0"
E
29°
0'0"
E
29°
30'0
"E
29°
30'0
"E
30°
0'0"
E
30°
0'0"
E
41°
0'0"
N
41°
0'0"
N
41°
30'0
"N
41°
30'0
"N
No C
ascad
e*0.8
+C
ascad
e*0
.2P
GA
(g)
10
% P
E in
50yr
s
0.0
- 0.1
0.1
- 0.2
0.2
- 0.3
0.3
- 0.4
0.4
- 0.6
0.6
- 0.8
0.8
- 1.0
1.0
- 1.5
1.5
-
010
2030
405
km
S6
S7
S4
S5
S9
S8
S3
S10
28°
0'0"
E
28°
0'0"
E
28°
30'0
"E
28°
30'0
"E
29°
0'0"
E
29°
0'0"
E
29°
30'0
"E
29°
30'0
"E
30°
0'0"
E
30°
0'0"
E
41°
0'0"
N
41°
0'0"
N
41°
30'0
"N
41°
30'0
"N
KO
ER
I M
odel
PG
A(g
) 1
0% P
E in 5
0yr
s
0.0
- 0.1
0.1
- 0.2
0.2
- 0.3
0.3
- 0.4
0.4
- 0.6
0.6
- 0.8
0.8
- 1.0
1.0
- 1.5
1.5
-
010
2030
405
km
30°
0'0"
E
30°
0'0"
E
29°
30'0
"E
29°
30'0
"E
29°
0'0"
E
29°
0'0"
E
28°
30'0
"E
28°
30'0
"E
28°
0'0"
E
28°
0'0"
E
41°
30'0
"N
41°
30'0
"N
41°
0'0"
N
41°
0'0"
N
OY
O+K
OER
IP
GA
(g)
10% P
E in 5
0 y
rs
0.0
- 0.1
0.1
- 0.2
0.2
- 0.3
0.3
- 0.4
0.4
- 0.6
0.6
- 0.8
0.8
- 1.0
1.0
- 1.5
1.5
-
010
2030
405
km
PGA
map
for 1
0% P
E in
50
year
s
28°
0'0"
E
28°
0'0"
E
28°
30'0
"E
28°
30'0
"E
29°
0'0"
E
29°
0'0"
E
29°
30'0
"E
29°
30'0
"E
30°
0'0"
E
30°
0'0"
E
41°
0'0"
N
41°
0'0"
N
41°
30'0
"N
41°
30'0
"N
No C
ascad
e*0.8
+C
ascad
e*0
.2P
GA
(g)
2%
PE in 5
0yr
s
0.0
- 0.1
0.1
- 0.2
0.2
- 0.3
0.3
- 0.4
0.4
- 0.6
0.6
- 0.8
0.8
- 1.0
1.0
- 1.5
1.5
-
010
2030
405
km
S6
S7
S4
S5
S9
S8
S3
S10
28°
0'0"
E
28°
0'0"
E
28°
30'0
"E
28°
30'0
"E
29°
0'0"
E
29°
0'0"
E
29°
30'0
"E
29°
30'0
"E
30°
0'0"
E
30°
0'0"
E
41°
0'0"
N
41°
0'0"
N
41°
30'0
"N
41°
30'0
"N
KO
ER
I M
odel
PG
A(g
) 2
% P
E in 5
0yr
s
0.0
- 0.1
0.1
- 0.2
0.2
- 0.3
0.3
- 0.4
0.4
- 0.6
0.6
- 0.8
0.8
- 1.0
1.0
- 1.5
1.5
-
010
2030
405
km
30°
0'0"
E
30°
0'0"
E
29°
30'0
"E
29°
30'0
"E
29°
0'0"
E
29°
0'0"
E
28°
30'0
"E
28°
30'0
"E
28°
0'0"
E
28°
0'0"
E
41°
30'0
"N
41°
30'0
"N
41°
0'0"
N
41°
0'0"
N
OY
O+K
OER
IP
GA
(g)
2% P
E in 5
0 y
rs
0.0
- 0.1
0.1
- 0.2
0.2
- 0.3
0.3
- 0.4
0.4
- 0.6
0.6
- 0.8
0.8
- 1.0
1.0
- 1.5
1.5
-
010
2030
405
km
PGA
map
for 2
% P
E in
50
year
s
OIC
Mod
el
KO
ERI M
odel
Av
erag
e of
OIC
and
KO
ERI M
odel
Fi
g. 8
.1.4
.1
PGA
map
by
OIC
Mod
el, K
OE
RI M
odel
and
Ave
rage
of t
hem
34
28°
0'0"
E
28°
0'0"
E
28°
30'0
"E
28°
30'0
"E
29°
0'0"
E
29°
0'0"
E
29°
30'0
"E
29°
30'0
"E
30°
0'0"
E
30°
0'0"
E
41°
0'0"
N
41°
0'0"
N
41°
30'0
"N
41°
30'0
"N
No C
ascad
e*0.8
+C
ascad
e*0
.2Sa(
g) h
=5%
t=0.
2se
c 5
0%
PE in 5
0yrs
0.0
- 0.1
0.1
- 0.2
0.2
- 0.3
0.3
- 0.4
0.4
- 0.6
0.6
- 0.8
0.8
- 1.0
1.0
- 1.5
1.5
-
010
2030
405
km
S6
S7
S4
S5
S9
S8
S3
S10
28°
0'0"
E
28°
0'0"
E
28°
30'0
"E
28°
30'0
"E
29°
0'0"
E
29°
0'0"
E
29°
30'0
"E
29°
30'0
"E
30°
0'0"
E
30°
0'0"
E
41°
0'0"
N
41°
0'0"
N
41°
30'0
"N
41°
30'0
"N
KO
ER
I M
odel
Sa(
g) h
=5%
t=0.
2se
c 5
0%
PE in 5
0yrs
0.0
- 0.1
0.1
- 0.2
0.2
- 0.3
0.3
- 0.4
0.4
- 0.6
0.6
- 0.8
0.8
- 1.0
1.0
- 1.5
1.5
-
010
2030
405
km
30°
0'0"
E
30°
0'0"
E
29°
30'0
"E
29°
30'0
"E
29°
0'0"
E
29°
0'0"
E
28°
30'0
"E
28°
30'0
"E
28°
0'0"
E
28°
0'0"
E
41°
30'0
"N
41°
30'0
"N
41°
0'0"
N
41°
0'0"
N
OY
O+K
OER
ISa(
g) h
=5%
t=0.
2se
c 50%
PE in 5
0yr
s
0.0
- 0.1
0.1
- 0.2
0.2
- 0.3
0.3
- 0.4
0.4
- 0.6
0.6
- 0.8
0.8
- 1.0
1.0
- 1.5
1.5
-
010
2030
405
km
Sa(t=
0.2s
ec) m
ap fo
r 50%
PE
in 5
0 ye
ars
28°
0'0"
E
28°
0'0"
E
28°
30'0
"E
28°
30'0
"E
29°
0'0"
E
29°
0'0"
E
29°
30'0
"E
29°
30'0
"E
30°
0'0"
E
30°
0'0"
E
41°
0'0"
N
41°
0'0"
N
41°
30'0
"N
41°
30'0
"N
No C
ascad
e*0.8
+C
ascad
e*0
.2Sa(
g) h
=5%
t=0.
2se
c 1
0%
PE in 5
0yrs
0.0
- 0.1
0.1
- 0.2
0.2
- 0.3
0.3
- 0.4
0.4
- 0.6
0.6
- 0.8
0.8
- 1.0
1.0
- 1.5
1.5
-
010
2030
405
km
S6
S7
S4
S5
S9
S8
S3
S10
28°
0'0"
E
28°
0'0"
E
28°
30'0
"E
28°
30'0
"E
29°
0'0"
E
29°
0'0"
E
29°
30'0
"E
29°
30'0
"E
30°
0'0"
E
30°
0'0"
E
41°
0'0"
N
41°
0'0"
N
41°
30'0
"N
41°
30'0
"N
KO
ER
I M
odel
Sa(
g) h
=5%
t=0.
2se
c 1
0%
PE in 5
0yrs
0.0
- 0.1
0.1
- 0.2
0.2
- 0.3
0.3
- 0.4
0.4
- 0.6
0.6
- 0.8
0.8
- 1.0
1.0
- 1.5
1.5
-
010
2030
405
km
30°
0'0"
E
30°
0'0"
E
29°
30'0
"E
29°
30'0
"E
29°
0'0"
E
29°
0'0"
E
28°
30'0
"E
28°
30'0
"E
28°
0'0"
E
28°
0'0"
E
41°
30'0
"N
41°
30'0
"N
41°
0'0"
N
41°
0'0"
N
OY
O+K
OER
ISa(
g) h
=5%
t=0.
2se
c 10%
PE in 5
0yr
s
0.0
- 0.1
0.1
- 0.2
0.2
- 0.3
0.3
- 0.4
0.4
- 0.6
0.6
- 0.8
0.8
- 1.0
1.0
- 1.5
1.5
-
010
2030
405
km
Sa(t=
0.2s
ec) m
ap fo
r 10%
PE
in 5
0 ye
ars
28°
0'0"
E
28°
0'0"
E
28°
30'0
"E
28°
30'0
"E
29°
0'0"
E
29°
0'0"
E
29°
30'0
"E
29°
30'0
"E
30°
0'0"
E
30°
0'0"
E
41°
0'0"
N
41°
0'0"
N
41°
30'0
"N
41°
30'0
"N
No C
ascad
e*0.8
+C
ascad
e*0
.2Sa(
g) h
=5%
t=0.
2se
c 2
% P
E in
50yr
s
0.0
- 0.1
0.1
- 0.2
0.2
- 0.3
0.3
- 0.4
0.4
- 0.6
0.6
- 0.8
0.8
- 1.0
1.0
- 1.5
1.5
-
010
2030
405
km
S6
S7
S4
S5
S9
S8
S3
S10
28°
0'0"
E
28°
0'0"
E
28°
30'0
"E
28°
30'0
"E
29°
0'0"
E
29°
0'0"
E
29°
30'0
"E
29°
30'0
"E
30°
0'0"
E
30°
0'0"
E
41°
0'0"
N
41°
0'0"
N
41°
30'0
"N
41°
30'0
"N
KO
ER
I M
odel
Sa(
g) h
=5%
t=0.
2se
c 2
% P
E in
50yr
s
0.0
- 0.1
0.1
- 0.2
0.2
- 0.3
0.3
- 0.4
0.4
- 0.6
0.6
- 0.8
0.8
- 1.0
1.0
- 1.5
1.5
-
010
2030
405
km
30°
0'0"
E
30°
0'0"
E
29°
30'0
"E
29°
30'0
"E
29°
0'0"
E
29°
0'0"
E
28°
30'0
"E
28°
30'0
"E
28°
0'0"
E
28°
0'0"
E
41°
30'0
"N
41°
30'0
"N
41°
0'0"
N
41°
0'0"
N
OY
O+K
OER
ISa(
g) h
=5%
t=0.
2se
c 2% P
E in
50yr
s
0.0
- 0.1
0.1
- 0.2
0.2
- 0.3
0.3
- 0.4
0.4
- 0.6
0.6
- 0.8
0.8
- 1.0
1.0
- 1.5
1.5
-
010
2030
405
km
Sa(t=
0.2s
ec) m
ap fo
r 2%
PE
in 5
0 ye
ars
OIC
Mod
el
KO
ERI M
odel
Av
erag
e of
OIC
and
KO
ERI
Fig.
8.1
.4.2
Sa
(t=0
.2se
c) m
ap b
y O
IC M
odel
, KO
ER
I Mod
el a
nd A
vera
ge o
f the
m
35
28°
0'0"
E
28°
0'0"
E
28°
30'0
"E
28°
30'0
"E
29°
0'0"
E
29°
0'0"
E
29°
30'0
"E
29°
30'0
"E
30°
0'0"
E
30°
0'0"
E
41°
0'0"
N
41°
0'0"
N
41°
30'0
"N
41°
30'0
"N
No C
ascad
e*0.8
+Cas
cad
e*0
.2Sa(
g) h
=5%
t=1.
0se
c 5
0% P
E in
50y
rs
0.0
- 0.1
0.1
- 0.2
0.2
- 0.3
0.3
- 0.4
0.4
- 0.6
0.6
- 0.8
0.8
- 1.0
1.0
- 1.5
1.5
-
010
2030
405
km
S6
S7
S4
S5
S9
S8
S3
S10
28°
0'0"
E
28°
0'0"
E
28°
30'0
"E
28°
30'0
"E
29°
0'0"
E
29°
0'0"
E
29°
30'0
"E
29°
30'0
"E
30°
0'0"
E
30°
0'0"
E
41°
0'0"
N
41°
0'0"
N
41°
30'0
"N
41°
30'0
"N
KO
ER
I M
odel
Sa(
g) h
=5%
t=1.
0sec
50%
PE in
50y
rs
0.0
- 0.1
0.1
- 0.2
0.2
- 0.3
0.3
- 0.4
0.4
- 0.6
0.6
- 0.8
0.8
- 1.0
1.0
- 1.5
1.5
-
010
2030
405
km
30°
0'0"
E
30°
0'0"
E
29°
30'0
"E
29°
30'0
"E
29°
0'0"
E
29°
0'0"
E
28°
30'0
"E
28°
30'0
"E
28°
0'0"
E
28°
0'0"
E
41°
30'0
"N
41°
30'0
"N
41°
0'0"
N
41°
0'0"
N
OY
O+K
OER
ISa(
g) h
=5% t
=1.
0se
c 50
% P
E in
50yr
s
0.0
- 0.1
0.1
- 0.2
0.2
- 0.3
0.3
- 0.4
0.4
- 0.6
0.6
- 0.8
0.8
- 1.0
1.0
- 1.5
1.5
-
010
2030
405
km
Sa(t=
1.0s
ec) m
ap fo
r 50%
PE
in 5
0 ye
ars
28°
0'0"
E
28°
0'0"
E
28°
30'0
"E
28°
30'0
"E
29°
0'0"
E
29°
0'0"
E
29°
30'0
"E
29°
30'0
"E
30°
0'0"
E
30°
0'0"
E
41°
0'0"
N
41°
0'0"
N
41°
30'0
"N
41°
30'0
"N
No C
ascad
e*0.8
+Cas
cad
e*0
.2Sa(
g) h
=5%
t=1.
0se
c 1
0% P
E in
50yrs
0.0
- 0.1
0.1
- 0.2
0.2
- 0.3
0.3
- 0.4
0.4
- 0.6
0.6
- 0.8
0.8
- 1.0
1.0
- 1.5
1.5
-
010
2030
405
km
S6
S7
S4
S5
S9
S8
S3
S10
28°
0'0"
E
28°
0'0"
E
28°
30'0
"E
28°
30'0
"E
29°
0'0"
E
29°
0'0"
E
29°
30'0
"E
29°
30'0
"E
30°
0'0"
E
30°
0'0"
E
41°
0'0"
N
41°
0'0"
N
41°
30'0
"N
41°
30'0
"N
KO
ER
I M
odel
Sa(
g) h
=5%
t=1.
0sec
10%
PE in 5
0yrs
0.0
- 0.1
0.1
- 0.2
0.2
- 0.3
0.3
- 0.4
0.4
- 0.6
0.6
- 0.8
0.8
- 1.0
1.0
- 1.5
1.5
-
010
2030
405
km
30°
0'0"
E
30°
0'0"
E
29°
30'0
"E
29°
30'0
"E
29°
0'0"
E
29°
0'0"
E
28°
30'0
"E
28°
30'0
"E
28°
0'0"
E
28°
0'0"
E
41°
30'0
"N
41°
30'0
"N
41°
0'0"
N
41°
0'0"
N
OY
O+K
OER
ISa(
g) h
=5% t
=1.
0se
c 10
% P
E in
50yr
s
0.0
- 0.1
0.1
- 0.2
0.2
- 0.3
0.3
- 0.4
0.4
- 0.6
0.6
- 0.8
0.8
- 1.0
1.0
- 1.5
1.5
-
010
2030
405
km
Sa(t=
1.0s
ec) m
ap fo
r 10%
PE
in 5
0 ye
ars
28°
0'0"
E
28°
0'0"
E
28°
30'0
"E
28°
30'0
"E
29°
0'0"
E
29°
0'0"
E
29°
30'0
"E
29°
30'0
"E
30°
0'0"
E
30°
0'0"
E
41°
0'0"
N
41°
0'0"
N
41°
30'0
"N
41°
30'0
"N
No C
ascad
e*0.8
+Cas
cad
e*0
.2Sa(
g) h
=5%
t=1.
0sec
2
% P
E in
50yr
s
0.0
- 0.1
0.1
- 0.2
0.2
- 0.3
0.3
- 0.4
0.4
- 0.6
0.6
- 0.8
0.8
- 1.0
1.0
- 1.5
1.5
-
010
2030
405
km
S6
S7
S4
S5
S9
S8
S3
S10
28°
0'0"
E
28°
0'0"
E
28°
30'0
"E
28°
30'0
"E
29°
0'0"
E
29°
0'0"
E
29°
30'0
"E
29°
30'0
"E
30°
0'0"
E
30°
0'0"
E
41°
0'0"
N
41°
0'0"
N
41°
30'0
"N
41°
30'0
"N
KO
ER
I M
ode
lSa(
g) h
=5%
t=1.
0sec
2%
PE in
50yr
s
0.0
- 0.1
0.1
- 0.2
0.2
- 0.3
0.3
- 0.4
0.4
- 0.6
0.6
- 0.8
0.8
- 1.0
1.0
- 1.5
1.5
-
010
2030
405
km
30°
0'0"
E
30°
0'0"
E
29°
30'0
"E
29°
30'0
"E
29°
0'0"
E
29°
0'0"
E
28°
30'0
"E
28°
30'0
"E
28°
0'0"
E
28°
0'0"
E
41°
30'0
"N
41°
30'0
"N
41°
0'0"
N
41°
0'0"
N
OY
O+K
OER
ISa(
g) h
=5% t
=1.0
sec
2% P
E in
50y
rs
0.0
- 0.1
0.1
- 0.2
0.2
- 0.3
0.3
- 0.4
0.4
- 0.6
0.6
- 0.8
0.8
- 1.0
1.0
- 1.5
1.5
-
010
2030
405
km
Sa(t=
1.0s
ec) m
ap fo
r 2%
PE
in 5
0 ye
ars
OIC
Mod
el
KO
ERI M
odel
Av
erag
e of
OIC
and
KO
ER
Fig.
8.1
.4.3
Sa
(t=1
.0se
c) m
ap b
y O
IC M
odel
, KO
ER
I Mod
el a
nd A
vera
ge o
f the
m
36
28°
0'0"E
28°
0'0"
E
28°
30'0
"E
28°
30'0
"E
29°
0'0"E
29°
0'0"
E
29°
30'0
"E
29°
30'
0"E
30°
0'0"E
30°
0'0"E
41°
0'0
"N
41°
0'0"
N
41°
30'
0"N
41°
30'0
"N
No C
ascad
e*0.8
+C
ascad
e*0
.2P
GV
(m/se
c)
10%
PE in 5
0yrs
0.0
- 0.1
0.1
- 0.2
0.2
- 0.3
0.3
- 0.4
0.4
- 0.6
0.6
- 0.8
0.8
- 1.0
1.0
- 1.5
1.5
-
010
2030
405
km
S6
S7
S4
S5
S9
S8
S3
S10
28°
0'0"E
28°
0'0"
E
28°
30'0
"E
28°
30'0
"E
29°
0'0"E
29°
0'0"
E
29°
30'0
"E
29°
30'
0"E
30°
0'0"E
30°
0'0"E
41°
0'0
"N
41°
0'0"
N
41°
30'
0"N
41°
30'0
"N
KO
ER
I M
odel
PG
V(m
/se
c)
50%
PE in 5
0yrs
0.0
- 0.1
0.1
- 0.2
0.2
- 0.3
0.3
- 0.4
0.4
- 0.6
0.6
- 0.8
0.8
- 1.0
1.0
- 1.5
1.5
-
010
2030
405
km
30°
0'0
"E
30°
0'0
"E
29°
30'0
"E
29°
30'0
"E
29°
0'0"
E
29°
0'0"
E
28°
30'
0"E
28°
30'0
"E
28°
0'0"
E
28°
0'0"
E
41°
30'
0"N
41°
30'
0"N
41°
0'0
"N
41°
0'0
"N
OY
O+K
OER
IP
GV
(m/se
c)
50%
PE in 5
0yrs
0.0
- 0.1
0.1
- 0.2
0.2
- 0.3
0.3
- 0.4
0.4
- 0.6
0.6
- 0.8
0.8
- 1.0
1.0
- 1.5
1.5
-
010
2030
405
km
PGV
map
for 5
0% P
E in
50
year
s
28°
0'0"E
28°
0'0"
E
28°
30'0
"E
28°
30'0
"E
29°
0'0"E
29°
0'0"
E
29°
30'0
"E
29°
30'
0"E
30°
0'0"E
30°
0'0"E
41°
0'0
"N
41°
0'0"
N
41°
30'
0"N
41°
30'0
"N
No C
ascad
e*0.8
+C
ascad
e*0
.2P
GV
(m/se
c)
10%
PE in 5
0yrs
0.0
- 0.1
0.1
- 0.2
0.2
- 0.3
0.3
- 0.4
0.4
- 0.6
0.6
- 0.8
0.8
- 1.0
1.0
- 1.5
1.5
-
010
2030
405
km
S6
S7
S4
S5
S9
S8
S3
S10
28°
0'0"E
28°
0'0"
E
28°
30'0
"E
28°
30'0
"E
29°
0'0"E
29°
0'0"
E
29°
30'0
"E
29°
30'
0"E
30°
0'0"E
30°
0'0"E
41°
0'0
"N
41°
0'0"
N
41°
30'
0"N
41°
30'0
"N
KO
ER
I M
odel
PG
V(m
/se
c)
10%
PE in 5
0yrs
0.0
- 0.1
0.1
- 0.2
0.2
- 0.3
0.3
- 0.4
0.4
- 0.6
0.6
- 0.8
0.8
- 1.0
1.0
- 1.5
1.5
-
010
2030
405
km
30°
0'0
"E
30°
0'0
"E
29°
30'0
"E
29°
30'0
"E
29°
0'0"
E
29°
0'0"
E
28°
30'
0"E
28°
30'0
"E
28°
0'0"
E
28°
0'0"
E
41°
30'
0"N
41°
30'
0"N
41°
0'0
"N
41°
0'0
"N
OY
O+K
OER
IP
GV
(m/se
c)
10%
PE in 5
0yrs
0.0
- 0.1
0.1
- 0.2
0.2
- 0.3
0.3
- 0.4
0.4
- 0.6
0.6
- 0.8
0.8
- 1.0
1.0
- 1.5
1.5
-
010
2030
405
km
PGV
map
for 1
0% P
E in
50
year
s
28°
0'0"E
28°
0'0"
E
28°
30'0
"E
28°
30'0
"E
29°
0'0"E
29°
0'0"
E
29°
30'0
"E
29°
30'
0"E
30°
0'0"E
30°
0'0"E
41°
0'0
"N
41°
0'0"
N
41°
30'
0"N
41°
30'0
"N
No C
ascad
e*0.8
+C
ascad
e*0
.2P
GV
(m/se
c)
2%
PE in 5
0yr
s
0.0
- 0.1
0.1
- 0.2
0.2
- 0.3
0.3
- 0.4
0.4
- 0.6
0.6
- 0.8
0.8
- 1.0
1.0
- 1.5
1.5
-
010
2030
405
km
S6
S7
S4
S5
S9
S8
S3
S10
28°
0'0"E
28°
0'0"
E
28°
30'0
"E
28°
30'0
"E
29°
0'0"E
29°
0'0"
E
29°
30'0
"E
29°
30'
0"E
30°
0'0"E
30°
0'0"E
41°
0'0
"N
41°
0'0"
N
41°
30'
0"N
41°
30'0
"N
KO
ER
I M
odel
PG
V(m
/se
c)
2% P
E in
50yr
s
0.0
- 0.1
0.1
- 0.2
0.2
- 0.3
0.3
- 0.4
0.4
- 0.6
0.6
- 0.8
0.8
- 1.0
1.0
- 1.5
1.5
-
010
2030
405
km
30°
0'0
"E
30°
0'0
"E
29°
30'0
"E
29°
30'0
"E
29°
0'0"
E
29°
0'0"
E
28°
30'
0"E
28°
30'0
"E
28°
0'0"
E
28°
0'0"
E
41°
30'
0"N
41°
30'
0"N
41°
0'0
"N
41°
0'0
"N
OY
O+K
OER
IP
GV
(m/se
c)
2% P
E in
50yr
s
0.0
- 0.1
0.1
- 0.2
0.2
- 0.3
0.3
- 0.4
0.4
- 0.6
0.6
- 0.8
0.8
- 1.0
1.0
- 1.5
1.5
-
010
2030
405
km
PGV
map
for 2
% P
E in
50
year
s
OY
O M
odel
K
OER
I Mod
el
Aver
age
of O
YO
and
KO
ERI M
odel
Fig.
8.1
.4.4
PG
V m
ap b
y O
IC M
odel
, KO
ER
I Mod
el a
nd A
vera
ge o
f the
m
37
8.2 Surface Ground Motion Analysis To produce surface ground motion related zonation map, following two types of zonation are conducted
and overlaid for final result.
Zonation A): Based on the average spectral acceleration with site response analysis
Zonation B): Based on the short period spectral amplification factor of subsurface soil depending on
average shear wave velocity
The outline flow chart for analysis is shown in Fig. 8.2.1. The main components are ground modeling,
site response analysis and zonation.
Zonation with Average
Spectral AccelerationAs/Bs/Cs/Ds/Es
Zonation with Short Period
Spectral AccelerationAv/Bv/Cv/Dv/Ev
Zonation withGround Shaking Hazard
AGS/BGS/CGS/DGS/EGS
Earthquake Hazard Map
Site Response Analys
PGA atEngineering Bedrock10%PE in 50 years
Ground Model overVs>760m/s layer
PS logging Micro Tremor ReMiBoring
Shear Modulus/Damping as a
function of strain
Sa (h=5%) at Engineering Baedrock
10%PE in 50 years
3 Input TimeHistories
Sa (h=5%)at Surface0.1 - 1.0sec
AVS30
Correction atvalley & basin
Sa (h=5%)at Surface
0.2sec
Fig. 8.2.1 Flow for Surface Ground Motion Analysis
38
8.2.1 Ground Modeling 8.2.1.1 Shallow Ground Model
In modeling of shallow ground, following three site investigation data are used.
- PS Logging
- Boring Log (Formation, Lithology)
- ReMi
The flowchart of shallow ground modeling is shown in Fig. 8.2.1.1. Based on the data availability, the
grids are classified to following five classes. The distributions of these classes are shown in Fig. 8.2.1.2.
a) PS Logging + Boring Log (162 grids)
b) ReMi + Boring Log (2531 grids)
c) only ReMi (58 grids)
d) only Boring Log (135 grids)
e) None (26 grids)
The median Vs of each formation is shown in Table 8.2.1.1.
39
Shallow Ground Model(0 to 30 meters)
Necessary Data- S wave Velocity (Vs) (layer and value)- Density- Formation and PI (cohesive soil for dynamic property)
Contents ofSite Investigation
in the Grid
PS Logging + Boring Log(162 grids)
ReMi + Boring Log(2531 grids)
Only ReMi(58 grids)
Only Boring Log(135 grids)
None(26 grids)
Vs: from PS Logging
Density: from Formation in Boring Log
Formation and PI: from Labo test
Vs: from ReMi (Upper and Lower limits are defined)
Density: from Formation in Boring Log
Formation and PI: from Labo test
Vs: from ReMi (Upper and Lower lomits are defined)
Density: estimated from Boring Logs in surrounding grids
Formation and PI: estimated from Boring Logs in surrounding grids
Vs: estimated from Formation and Depth
Density: from Formation in Boring Log
Formation and PI: from Labo test
Vs: estimated form surrounding grids
Density: estimated from surrounding grids
Formation and PI: estimated from surrounding grids
YES
NO
YES
YES
YES
YES
NO
NO
NO
Fig. 8.2.1.1 Flowchart for Shallow Ground Modeling
40
Legend
PS+Boring
ReMi+Boring
ReMi
Boring
None
Fig. 8.2.1.2 Used Site Investigations to make the Shallow Ground Model
Table 8.2.1.1 S wave velocity for 0 to 30 meters depth
10% Median 90%Yapay Dolgu Qyd 0.13 0.19 0.26Bitkisel Toprak Qts 0.15 0.25 0.35Plaj KumAlüvyonKuşdiliAlüvyon Clay, Silt Ac 0.13 0.20 0.26Kuşdili Gravel Ag 1) - - -
Soil Tceb1 0.21 0.29 0.44Rock Tceb2 0.24 0.36 0.48Soil Tceg1 0.20 0.31 0.40
Rock Tceg2 0.27 0.37 0.43Soil Tc1 0.20 0.33 0.48
Rock Tc2 0.27 0.37 0.43Soil Tdg1 0.26 0.36 0.48
Rock Tdg2 0.28 0.39 0.50Soil Tkc1 0.40 0.55 0.65
Ceylan 0 - 10m 0.31 0.47 0.85Soğucak 10 - 20m 0.45 0.81 0.89
20 - 30m 0.47 0.85 1.03Soil Ctw 2) 0.27 0.57 0.77
0 - 10m 0.27 0.57 0.7710 - 20m 0.59 0.93 1.8320 - 30m 0.83 1.19 1.83
1) No Vs data was available by PS logging2) No Vs data was available by PS logging. Vs is assumed to be same to Ct (0-10m).
Rock
TrakyaRock Ct
Güngören
0.16 0.22 0.32
Gürpınar
Tkc2
Vs(km/sec)Formation Lithology Symbol Depth
Çukurçeşme
Sand As
Bakırköy
41
8.2.1.2 Deep Ground Model In modeling of deep ground, following three site investigation data and existing PS logging in JICA study
are used.
- Deep PS Logging
- Deep Boring Log (Formation, Lithology)
- Array Microtremor Measurement
- PS Logging in JICA Study
The flowchart of deep ground modeling and total ground modeling is shown in Fig. 8.2.1.3. At first, the
bottom of Alluvium layer, Bakirkoy, Gungoren/Cukurcesme formation and surface of Ceylan or Trakya
formation was depicted mainly by deep boring logs. Next, the surface of engineering bedrock was decided by
deep PS logging results, existing PS loggings, array microtremor results and deep boring logs. The Vs of each
formation was decided based on the analysis on the relation of Vs by PS logging and formation.
Surface ofVs=760m/s
layer
Bottom ofGungoren/
CukurcesmeFormation
Bottom ofBakirkoyFormation
Bottom ofAlluviumLayer
Deep Ground Model(Deeper than 30 meters to Vs=760m/s layer)
Typical Density byFormation
Typical Vs byFormation and Depth
Shallow Ground Model- Shallow Ground Model has priority- Deeper Ground Model is modified to fir the Shallow Model
Groung Model for Response Analysis
Surface ofCeylan orTrakya
Formation
Fig. 8.2.1.3 Flowchart for Deep Ground Modeling and Total Ground Model for Response Analysis
Table 8.2.1.2 is adopted as Vs value for deep ground.
42
Table 8.2.1.2 S wave velocity for deeper than 30 meters depth
Alüvyon A 0.32Bakırköy Tceb 0.47GüngörenÇukurçeşme
30 - 50m 0.4050 - 100m 0.44
100 - 150m 0.51150m - 0.59
CeylanSoğucak
Trakya Ct 1.20
Tceg+Tc
TdgGürpınar
Tkc
Formation
0.38
0.87
Symbol Depth Vs(km/sec)
8.2.2 Site Amplification Analysis Earthquake motion at ground surface is strongly affected by subsurface soil structures, especially in the
area covered by quaternary sediments. The effects of soils on seismic motion were evaluated by response
analysis based on the ground models of each 250 m grid. In valley and basins, where 2D effects of
amplification will be expected, additional amplification factor derived from the comparison between 1D
analysis and 2D analysis was introduced.
8.2.2.1 Site Response Analysis The amplification of subsurface soil over engineering seismic bedrock was estimated by the 1D response
analysis code “SHAKE 91”. This code analyses the propagation of shear wave through horizontally layered
media over engineering bedrock. The following settings or conditions were adopted in the analysis.
(1) Input motion amplitude
The engineering seismic bedrock motion calculated in Chapter 8 was defined at NEHRP B/C boundary,
namely Vs=760m/sec layer. However, the formation of engineering bedrock is not uniform and the Vs of
engineering bedrock is not uniform within the study area. The input motion amplitude for response analysis
should be corrected based on the differences of Vs at engineering bedrock. The following empirical relation
of Vs and amplification by Midorikawa et al. (1994) was used for this purpose. The amplification by this
relation for the layer with Vs=760m/sec is almost 1.0 and the ratio of amplification factor for another Vs was
used as the correction factor. The PGA distribution at engineering bedrock with Vs=760m/sec is shown in Fig.
8.2.2.1.
43
(m/sec) m 30 ofdepth a to velocity wave-S average:PGAfor factor ion amplificat:
log47.035.1log
VR
VR −=
Fig. 8.2.2.1 Input ground motion acceleration levels at NEHRP B/C boundary
(2) Input seismic wave
The amplification characteristics of subsurface layers differ depending on input seismic waves to the
ground model. In this study, the following three strong motion records during the 1999 Izmit Earthquake and
Duzce Earthquake were used under the guidance of board member. The parameters and wave forms are
shown in Table 8.2.2.1 and Fig. 8.2.2.2.
The amplitudes of waves were arranged for PGA at the engineering seismic bedrock in each grid. The
averaged value of three results, which correspond to three input waves, was used as the final result.
Table 8.2.2.1 Parameters of Input Waves
Name Latitude Longitude Earthquake Date M ClosestDistance Component Acc. max Preferred
AVS301062NS 40.723 30.82 Duzce 1999.11.12 7.1 9.2km NS 0.114g 338m/s
ARC 40.8236 29.3607 Kocaeli 1999.8.17 7.4 13.5km EW 0.149g 523m/sGBZ 40.82 29.44 Kocaeli 1999.8.17 7.4 10.9km NS 0.244g 792m/s
Source: PEER Strong Motion Database
44
1062NS
-0.2
-0.1
0
0.1
0.2
0 5 10 15 20 25 30 35 40 45Acc.
(g)
ARC
-0.2
-0.1
0
0.1
0.2
0 5 10 15 20 25 30 35Acc.
(g)
GBZ
-0.3
-0.15
0
0.15
0.3
0 5 10 15 20 25 30Acc.
(g)
Fig. 8.2.2.2 Used Input Waves for Response Analysis
8.2.2.2 Earthquake Ground Motion The earthquake ground motion was evaluated by response analysis and valley/basin correction. The PGA
distribution at ground surface is shown in Fig. 8.2.2.3.
Fig. 8.2.2.3 PGA distribution at ground surface including valley/basin correction
45
8.2.3 Zonation Related to the Surface Ground Motion 8.2.3.1 Zonation with respect to the Average Spectral Acceleration Fig. 8.2.3.1 shows the zonation of the average spectral acceleration (Ssi), which uses the criteria shown in
Table 8.2.3.1.
Table 8.2.3.1 Criteria of Zonation by Average Spectral Acceleration
Zone Criteria
As Ssi ≥ 1.4g
Bs 1.4g > Ssi ≥ 1.2g
Cs 1.2g > Ssi ≥ 1.0g
Ds 1.0g > Ssi ≥ 0.8g
Es 0.8g > Ssi
Fig. 8.2.3.1 Zonation with respect to the Average Spectral Acceleration
8.2.3.2 Zonation with respect to the Short Period Spectral Acceleration The short period (T=0.2 sec) spectral acceleration at ground surface was calculated after Borcherdt (1994).
Fig. 8.2.3.2 shows the zonation of the short period spectral acceleration (Svi), which uses the criteria shown
in Table 8.2.3.2.
46
Table 8.2.3.2 Criteria of Zonation by Spectral Amplification
Zone Criteria
Av Svi ≥ 1.2g
Bv 1.2g > Svi ≥ 1.0g
Cv 1.0g > Svi ≥ 0.8g
Dv 0.8g > Svi ≥ 0.6g
Ev 0.6g > Svi
Fig. 8.2.3.2 Zonation with respect to the Short Period Spectral Acceleration by Borcherdt (1994)
8.2.3.3 Zonation with Respect to the Ground Shaking Hazard
Remark
The zoning map by this methodology was intended to raise the awareness that the place of good
ground condition in general meaning is not always safe for the mid-rise RC frame with brick wall
residential apartments, which are very common in Istanbul. Please don’t misunderstand that the
“bad” ground condition is safe for buildings.
Fig. 8.2.2.4 and Fig. 8.2.3.1 should be used as the total seismic hazard maps.
47
The ground intensity shaking map was produced from two zonation results. A zone was assigned at each
grid by overlaying of “Zonation with respect to the Average Spectral Acceleration (As to Es)” and “Zonation
with respect to the Short Period Spectral Acceleration (Av to Ev)” following Table 8.2.3.3. Fig. 8.2.3.3 shows
the zonation with respect to the ground shaking hazard.
Table 8.2.3.3 Criteria of Zonation by Ground Shaking Hazard
Zonation with respect to the Average Spectral Acceleration As Bs Cs Ds Es
Av AGS AGS BGS BGS CGS
Bv AGS BGS BGS CGS DGS
Cv BGS BGS CGS DGS DGS
Dv BGS CGS DGS DGS EGS
Zon
atio
n w
ith r
espe
ct to
the
Shor
t Per
iod
Spec
tral
A
ccel
erat
ion
Ev CGS DGS DGS EGS EGS
Fig. 8.2.3.3 Zonation with respect to the Ground Shaking Hazard
48
8.3 Liquefaction Hazard Analysis In order to evaluate the liquefaction susceptibility of soils in the project area, the cyclic stress ratio (CSR)
caused by the ground motion due to the expected earthquake and the cyclic resistance ratio (CRR) of the soils
were compared. The overview of the procedure for the liquefaction hazard analysis are shown Fig. 8.3.1.
Fig. 8.3.1 Flow for Evaluation of Liquefaction Susceptibility
Geological Investigations
- Drilling for each grid (Depth:30m)
- SPT (every 1.5m), Laboratory Test
Selection of
Liquefaction Potential Areas
Extra Investigations
- Drilling, SPT, CPT, Labo. Test
Evaluation of Liquefaction Susceptibility
Result of SPT Result of CPT
Fs
PL
Liquefaction Hazard Map
AL
(High)
BL
(Medium)
CL
(Low)
(No Potential)
No potential
Any potential
49
8.3.1 Calculation for Liquefaction Susceptibility The calculations of liquefaction susceptibility were conducted by two methods, one using SPT
results and the other using CPT results. These calculation flows are shown in Fig. 8.3.1.1 and Fig. 8.3.1.2 respectively.
Fig. 8.3.1.1 Calculation for Liquefaction Susceptibility by SPT Data
CSR (Cyclic Stress Ratio)
CSR = 0.65 d'max rg
a⎟⎟⎠
⎞⎜⎜⎝
⎛⎟⎟⎠
⎞⎜⎜⎝
⎛
v
v
σσ
amax ρ z
N-value correction
N1,60=NCNCRCSCBCE
N
N-value correction for FC
N1,60,CS= α+βN1,60
CRR7.5 (Cyclic Resistance Ratio)
CRR7.5= 1/(34-N1,60)+N1,60/135+50/(10N1,60+45)2-1/200
MW
MSF (Magnitude Scaling Factor)
MSF=102.24/MW2.56
FS (Factor of Safety)
FS = (CRR7.5 / CSR) MSF
PL (Liquefaction Index)
PL=∫(1-FS)w(z)dz
50
Fig. 8.3.1.2 Calculations for Liquefaction Susceptibility by CPT Data
51
After calculating the liquefaction susceptibility, three zones were defined as Table 8.3.1.1.
Table 8.3.1.1 Zonation by Liquefaction Hazard
Zone Criteria Description
AL PL > 15 High susceptibility
BL 5 ≤ PL ≤ 15 Medium susceptibility
CL PL <5 Low susceptibility
8.3.2 Evaluation of Liquefaction Hazard
The Liquefaction Hazard Map was produced as shown in Fig.8.3.2.1. The following results are derived in
terms of the liquefaction susceptibility.
a) AL, “high liquefaction susceptibility” zones are typically observed at the following areas;
- The southern sand bank and the east bank of the Küçükçekmece Lake
- A part of the alluvium deposit area at the west part of the Lake
- A part of the alluvium deposit area along the Ayamama River
- The coastal areas to the Marmara Sea from Bakırköy to Eminönü
- A part of the west bank of the Golden Horn
b) BL, “medium susceptibility “ zones or CL, “low susceptibility” zones are typically observed at the
following areas;
- The west part of the Lake
- The westernmost part of the project area
- The most of alluvium deposit areas in the middle part of the project area
c) The high – medium susceptibility zones are generally observed in the alluvium or fill deposit areas. In
case the tertiary deposits consist of sands or silty-sands with high groundwater level, these soils rarely
have the liquefaction susceptibility.
d) In general, the high susceptibility zones exist very locally except the southern sand bank and the east
bank of the Küçükçekmece Lake.
52
Fig. 8.3.2.1 Liquefaction Hazard Map
53
8.4 Mass Movements (Slope Instability) 8.4.1 Method for the Landslide Hazard Analysis
8.4.1.1 Evaluation of the Present Landslide Activities The categorized landslides area shown in Table 8.4.1.1.
Table 8.4.1.1 Proposed evaluation for the present activity of landslides
Activity Damages of buildings, topographic features
Activity I - Very clear landslide morphology
- There are two or more damages with displacement of 10 cm or more.
Furthermore, lots of other damages are observed.
- It is inferred that these landslides will move by 1 – 10cm per year.
Activity II - Clear landslide morphology
- There are two or more damages with displacement of 1 - 10 cm.
- It is inferred that these landslides will move by 1 cm or less per year.
Activity III - Not clear landslide morphology
- Lots of damages possibly caused by landslides are observed.
- These landslides seem to be slightly active or the slopes are instable.
Activity IV - Not clear landslide morphology
- Some damages possibly caused by landslides are observed.
- These landslides seem to be slightly active or the slopes are instable.
Activity V - Not clear landslide morphology
- Some damages possibly caused by landslides are observed.
- These landslides seem to be slightly active.
8.4.1.2 Shear Strength of Soils by Shear Box Test The shear box tests were conducted using UD and SPT samples in the landslide areas. These samples
consist of the Gungoren clay or Gurpinar clay at the depth of 7m – 10m.
Table 8.4.1.2 shows the shear resistance angle for each landslide activity.
Table 8.4.1.2 Shear Resistance Angle for Each Landslide Activity
Activity Rank Ⅰ Ⅱ Ⅲ Ⅳ Ⅴ
Shear Strength Angle (degree) 5 7 10 15 20
54
8.4.1.3 Examination of Estimation of the Shear Resistance Angle The relation of the safety factor, the slope inclination of the landslide, and the strength of the slip surface is
shown in the following formula (1) and the chart (Fig. 8.4.1.1), by Siyahi and Ansal (1999).
Using this formula, the strength of the slip surface for the present situation can be estimated by
back-calculation using the safety factor of each landslide block, where pga(g) is peak ground acceleration
during earthquake and “pga=0” implies non-earthquake situation.
Fs = tanφ N1 (pga) --------------------------- (1)
Fs：safety factor
φ：friction angle (for total stress)
N1(pga)： minimum stability number according to pga ( coefficient given with the
following chart)
Fig. 8.4.1.1 Relation of the slope inclination of the landslide, and the strength of the slip surface
The present safety factor (without earthquake) can be calculated by applying pga=0 to the previous formula
(1). Fig. 8.4.1.2 shows the present safety factor for each landslide activity.
55
Safety Factor at Present
0
1
2
3
4
5
6
7
0 5 10 15 20
Inclination of Landslide
Safe
ty F
act
or Activity Ⅰ
Activity Ⅱ
Activity Ⅲ
Activity Ⅳ
Activity Ⅴ
Fig. 8.4.1.2 Present Safety Factor for Each Landslide Activity
According to the result, the safety factors of landslides with the highest activity are 1.0 – 1.2. These values
are reasonable considering that these landslides are unstable at present causing some damage to buildings. The
low active landslides show considerably high safety factors. The estimated shear resistance angles can be
judged proper as a whole.
8.4.1.4 Calculation of the Safety Factor at the Earthquake The safety factor at the earthquake can be calculated using the previous formula (1). This formula is based
on a laboratory test using the Caolin (clay with low plasticity), of which the soil strength will become fairly
lower due to earthquakes. Ordinary clayey soils generally have higher plasticity. That means the formula (1)
represents the most dangerous case.
Taking the above consideration into account, it will be an overestimation if the PGA value itself is used for
the formula (1). In general, around 30% of the peak ground motion (PGA) is used for the effective ground
motion for grounds or buildings. Therefore, 30 % of PGA is used as the ground motion for the formula (1).
8.4.2 Evaluation of the Landslide Hazard The evaluation by the safety factor at the earthquake is the relative one based on the presumption of the
present safety factor and the decrease of PGA.
Of the landslides in the project area, there are ones with clear landslide morphology and ones with not clear
morphology. The landslides with clear morphology have possibly moved every time the big earthquake occurs,
56
while the landslides with not clear morphology have not moved for more than 1,000 years.
Therefore, a landslide which has the same safety factor as the ones with clear landslide morphology is
expected to move at the next big earthquake. On the other hand, a landslide which has the same safety factor as
the ones with not clear landslide morphology is not expected at the next big earthquake.
Fig. 8.4.2.1 shows the relation of the extent of development of the landslide morphology and the safety
factor at the earthquake. According to this relation, the safety factor of landslides with clear morphology is less
than 1.0. In case the safety factor is more than 2.0, the landslide hazard risk will be relatively low.
Safety Factor at Earthquake and Landslide Topography
0.00
0.50
1.00
1.50
2.00
2.50
3.00
3.50
4.00
0 5 10 15 20
Inclination of Landslide
Saf
ety
Fac
tor
at E
arth
quak
e
Not Clear
Medium
Developed
Fig. 8.4.2.1 Development of landslide topography and safety factor at earthquake
Taking these considerations into account, the landslide hazard risk can be divided into the following three
categories.
Fs ≤ 1.0 ASL (High risk )
1.0< Fs < 2.0 BSL (Medium risk)
Fs ≥ 2.0 CSL (Low risk)
Fig. 8.4.2.2 shows the Landslide Hazard Map.
57
Fig. 8.4.2.2 Landslide Hazard Map
58
9 WATER STATUS
9.1 Ground Water Levels In order to observe water level, 50mm diameter of PVC pipes were inserted into 4364 mechanical
boreholes with different depths (except PS Logging and Deep Wells) just after completion of drilling works.
The top of each borehole was covered by concrete block to maintain the borehole under protection for the
observation.
Water level measurements were done in 2 or 3 days after the completion of boreholes. Water levels in boreholes were observed once a month for a year (as optimum twelve times) from completion of drilling works. Each result were recorded in the prepared forms and digitized.
During the measurements, water level in some boreholes measured higher than other surrounding
boreholes due to remaining drilling water in these boreholes (water couldn’t pomped out efficiently after
completion of drilling). Data collected from these boreholes were used in estimations if the water level
decreased to a similar level with the surrounding borehole water levels in two or three monts time.
Measures that shows major dissonance (very low or very high) to measures of surrounding borehole water
levels, were ignored. Measures in drilling points, which was damaged and not possible to get enough data,
were reflacted to the maps with using geophysical data and correlation of measurement in surrounding
boreholes.
In final table, it was seen that water levels measured in summer time are similar to water levels measured
in winter time. The Highest water level values were used in the maps mantioned above, because
groundwater level is most important factor for espacially liquefaction and landslide analysis. Forms with
whole measurements can be found in CDs attached to this raport. Figure 9.1.1 shows elevation distribution of groundwater tray regarding the sea water level. Averaged
groundwater levels are corresponded to topography so the water level is high on hills while it drops in low
lands. Water level is same or similar to sea water level or contiguous river levels. Figure 9.1.2 showes
grounwater depth contour from surface.
59
Fig. 9.1.1 Groundwater Level Elevation Contour from Average Sea Water Level
60
Fig. 9.1.2 Groundwater level depth contour from surface
61
9.2 Flooding Hazard Analysis The “Flooding Hazard” consists of the following two types of hazard:
a) Flooding along the lower river areas due to a dam break (referred as to ‘Dam Break Model’).
b) Flooding along the river areas due to over-precipitation (referred as to ‘River Flooding Model’).
9.2.1 Analysis Method A finite difference method by the 2D Shallow Water Equation was used for the numerical analysis for the
Flooding Analysis (both of the Dam Break Model and the River Flooding Model)
9.2.2 Analysis Results 9.2.2.1 Dam Break Model There are two areas for the analysis by the Dam Break model as shown in Fig. 9.2.2.1.
Fig. 9.2.2.1 Area for Dam Break Model
Sazlıdere Dam Alibey Dam
62
The maximum flow dapth due to the dam break is shown in Fig.9.2.2.2 for Sazlidere Dam and Fig.9.2.2.3
for Alibey Dam respectively.
Fig. 9.2.2.2 Maximum Depth (Sazlıdere Dam)
Maximum Depth (m)
63
Fig. 9.2.2.3 Maximum Depth (Alibey Dam)
Maximum Depth (m)
64
9.2.2.2 River Flooding Model Total 6 regions were selected for the analysis by the river flooding model as shown in Fig. 9.2.2.4.
Fig. 9.2.2.4 Area for River Flooding Model
Region１ Region 2
Region 3
Region 4
Region 5 Region 6
65
9.2.3 Evaluation of Flooding Hazard Calculated results were evaluated in terms of the hazard assessment. The calculated results include a lot of
‘noise’ and some ‘unrealistic data’. For example, some large flooded areas in the River Flooding Model are
apparently due to the relatively high elevation of bridges (roads or railways) at the lower side. These data was
removed for the hazard mapping.
The evaluated areas were divided into three flooding hazard zones as shown in Table 9.2.3.1. The Flooding
Hazard Map was created as shown in Fig.9.2.3.1.
Table 9.2.3.1 Zonation by Flooding Hazard
Zone Criteria
AF (High hazard area) Flooding depth > 3m
BF (Medium hazard area) 0.5 m < Flooding depth ≤ 3m
CF (Low or no hazard area) Flooding depth ≤ 0.5m
Regarding the “Dam Break Model”, the dam break is the “worst” scenario and the actual possibility of the
dam break will be relatively very low. Therefore, the flooded areas by the dam break were categorized to the
zone “CF”.
The hazard levels for flooded areas by “the river flooding” were also evaluated taking into account the
existing flooding records. Then these areas were divided into two categories as BF and CF. There is no area
which will have the highest hazard as AF.
66
Fig. 9.2.3.1 Flooding Hazard Map
67
9.3 Tsunami Hazard Analysis Fig. 9.3.1 shows the flow of the Tsunami Hazard Analysis.
Fig. 9.3.1 Flow of Tsunami Hazard Analysis in this study
Earthquake Hazard Analysis Result
Historical Tsunami Catalogue
Bathymetry Data (Marmara Sea)
Topographical Analysis (vulnerable Submarine Slopes)
Response Analysis (PGA at slopes by active faults)
Stability Analysis (slip limit PGA for slopes)
Landslide Simulation (movement of slip mass of slopes)
Simple Probability of Tsunami for Istanbul
Active Faults Parameters
Tsunami Simulation
Tsunami Probability Analysis
Tsunami Probability Maps (vulnerable areas at Istanbul Shore)
Submarine Landslides Parameters
(verification)
68
9.3.1 Historical Tsunamis for Istanbul Fig. 9.3.1.1 is the distribution of historical tsunamis in Marmara Sea with space (Altinok, 2006b). Based
on Altinok (2006b) etc. 30 events of historical tsunami during these 20 centuries for Istanbul were identified.
Fig. 9.3.1.1 Historical tsunami in Marmara Sea from 120 to 1999 A.D. with space (Altinok, 2003)
9.3.2 Tsunami Simulation Samples of simulated results for the Princes’ Islands faults are shown in Fig. 9.3.2.1. East side especially
Adalar area of Istanbul city will be affected higher tsunami heights, and most of cases. The arrival time of
initial wave will be within 10 minutes, and the maximum tsunami wave will arrive within 60 to 90 minutes
after the generation of earthquake.
When Princes’ Island fault will move, Istanbul city area will be affected more than other faults of Ganos or
Central Marmara faults. Tsunami height to Adalar will reach 4 to 7 meters, to east side including Kadıköy or
Tuzla will be 3 to 5 meters, and to west side including Yenikapı Yeşilköy or Avcılar will be 3 to 4 meters. But
in Bosphorus and Golden Horn, tsunami height will be maximum 2 meters.
Run-up height (m; height from sea level) is similar to tsunami height along shore, but 30 to 80 % higher
than inundation depth. Thus inundation depth is 50 to 80% of tsunami height along shore.
69
Fig. 9.3.2 1(a) Simulated Results for Princes’ Island Fault
70
Fig. 9.3.2 1(b) Simulated Results for Princes’ Island Fault
71
9.3.3 Simulation Results of Submarine Landslides Samples of simulated results for EN1 of northern slope of Çinarcik Basin are shown in Fig. 9.3.3.1. East
side of Istanbul Municipality especially Adalar area will be affected higher tsunami heights. The arrival time of
initial wave will be within 10 minutes, and the maximum tsunami wave will arrive within 60 to 90 minutes
after the generation of earthquake.
Tsunami heights are maximum 4 to 5 m except West Marmara or ON2 southern Çinarcik Basin cases.
Inundation depths are maximum 3-4 m by EN1, EN3 and ON1 cases. Run-up heights are similar to inundation
depth.
9.3.4 Simulation Results of Combination of Active Faults and Submarine Landslides Fig. 9.3.4.1 shows a sample of the simulation results of combination of active faults and submarine
landslides.
9.3.5 Probability of Tsunami for Istanbul The tsunami wave height at the coast of 10% probability of exceedance for 50 years is shown in Fig.
9.3.5.1. The Asian side of Istanbul is more hazardous than European side. The highest wave height is expected
in Adalar and the highest wave height exceeds 9m. Kartal and Kadıköy are the next hazardous area in Asian
side. In the European side, 3 to 4 m height is expected in Bakırköy to Zeytinburnu.
The tsunami inundation depth at the seaside of 10% probability of exceedance for 50 years is shown in Fig.
9.3.5.2 and Fig. 9.3.5.3. The inundation at the south of Küçükçekmece Lake is remarkable. The maximum
inundation distance from the coast reaches about 600m. The seaside of Kadıköy and Kartal to Tuzla also
expected to suffer run-up for 100 to 300m from the coast.
72
Fig. 9.3.3.1 Simulated Results for EN1(northern Çinarcik Basin)
73
Fig. 9.3.4 1(a) Simulated Results of Active Faults and Landslides
74
Fig. 9.3.4 1(b) Simulated Results of Active Faults and Landslides
75
!! ! ! ! ! ! ! ! ! !!! !!!!!!!!!! !!!! !!!!!!!! !!!!! !!!! !!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!! !! ! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !! ! !!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !! !! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!! !!!!!!!!!! !!!! !!!!!!! !!! !!!! !!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!! !! !!!! ! !! !! ! ! !!! ! ! ! ! !! ! !! ! ! !!! !!!! !! ! ! ! ! ! ! ! ! !! !! !! ! ! !!!!! !!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!! !!!!! !!!!! !!!!! !! !!!!!!!! !!!! !!!!!!!!! !!!! !!!! !!! !! ! ! !!!!!!!!!!!!! !!!!!!!!! !!!!!! !!!!!!!!!!!!!!!!!!!! !!!!! !!!! !!!!!! !! ! ! ! ! !!! !!!!!!!! !! !! !!!!! !!!!!!!!!! !!!!! !!! !!! !!!!!!! !!! !!! !!!!!! !! ! !!!!!!!!!! !! !!!! !!! !! !!! !!! !! !!! !! !!! !! !! !!! !!!! !! !!! !! !!! !! !! !! !!! !! !! !! !! !! !! !! !! !!!! !! !!! !! ! !! !! !! !! !! ! !! !! !! !! !! !! ! !! !! !!! !! ! !! ! !! ! !!! ! ! ! ! ! ! ! !!! ! ! !!!! ! ! ! ! ! ! ! !! ! !!! !!!! !! !! ! !! !! !!!! !! ! !! !! ! !! !! ! ! !! ! ! ! ! ! ! ! ! !!!!! ! ! ! !!!!! !!! !! !! !! !! ! !! !! ! !! !! ! !! !! !! ! !! ! !! ! !! !! ! ! ! ! ! ! ! ! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!! !!!!!!! ! ! ! ! ! ! ! ! ! ! ! ! !!!!!!! !!!!!! !!!!!! !!!!! !!! !! !! !! !! !!! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !! ! ! ! ! ! ! ! ! !!!! ! !! ! ! !! ! !! !! ! ! !!! ! !!! !! !! !!!!! !!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!! !!! !!! !!! !!! ! ! ! ! ! ! ! ! ! ! !!! !!!!!!!!!!!!!!!!!!!!!! ! ! ! ! !!!!!!!!!!!!!!!!!!! !!!!!! ! ! ! ! ! ! ! !!!!!!!!!!!!! ! ! ! ! ! ! ! ! ! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!! !!! !!!! !! !! ! ! ! !!!!! ! !!!! ! ! !! !!!!!!!!!!!!!!!!!!!!!!!!!! ! ! ! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!! ! !!!!!!!!!!!!!!! ! ! ! ! ! ! ! ! ! !! !! !!! ! !! ! ! ! ! !! ! !!!!! !! ! !! !! ! !!!! ! ! !! ! !! ! ! ! ! !! ! ! !! ! ! !! !!! !! !! ! ! ! ! ! !! ! ! ! ! ! !!!!! !! ! ! !!!! ! ! !!!!!!! !!!! !!!!!!!!!! !!!! ! ! !!!! !! ! !!!!!!!! !!!!!! !! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!! !!!!! !!! ! ! ! ! ! !! !!! !! !!!!!!!!! ! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !! !! !! !! !!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!! !! !!!!!!!!!!!!!!!! !!!!!!!!! !!! !!! !!!!!!!!!!!!!!! !!! !!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!! !!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!
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!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! ! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
! ! ! ! !! ! !!! ! !!! ! ! ! !!!! ! ! ! !! ! ! ! ! !!!!!!!! ! ! ! ! ! ! ! ! ! !! !!!!! !!! !!! ! !! !!! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !! ! ! ! ! !! ! ! ! !!!!!!! ! ! ! ! ! ! !!!!!!!!! ! !!!!!! !!!!! !!!! !!! !! !!! ! ! ! ! ! ! ! ! ! ! ! !! ! ! ! !! ! ! ! ! !! !! ! ! !! !!!!!!!! !! ! ! ! ! ! ! ! ! ! ! ! ! ! !! ! ! !! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !! !! !!! !! ! !! ! ! ! !! !!!!!!!!!! !!!! ! ! ! !! ! ! ! ! ! ! ! ! ! ! ! ! ! !! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !!! !! !!! ! ! !! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !!!!!!!! !! !!!!! ! ! ! !! !! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !! !! !! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !! ! !!! ! ! !! !!!!!! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !!! ! !! !! !! ! !! ! !!! !! ! !! ! ! ! !!! ! !! !! ! !! ! ! ! !! ! ! ! ! !! ! ! ! ! !! !!! ! ! ! ! ! ! ! !! ! ! ! ! !!!!!!! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !!!!!! ! ! ! ! ! ! !!!! !!!! ! ! !!!!! ! ! ! ! !!!!
! !! ! ! ! ! ! ! ! ! ! ! !!!!! !!! ! ! ! ! ! ! ! !!! ! !!! !!!!! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !!!!!!!!!! !!!!!!!!!!!!!!!!!! ! ! ! ! ! ! ! ! ! ! !! ! ! ! ! !! ! ! ! !! !! ! ! ! ! ! ! ! ! ! ! !!!!!!! ! ! ! ! ! ! ! ! ! !! ! !!!!!!!!! !!! ! ! ! ! !! !!!!!!!!!!!!!! !!! ! ! ! !!! ! ! ! !! ! ! !!! !! ! ! !! !! !!!!!!!!!! !!! ! !! ! ! ! ! ! ! !! ! ! !!!!!! !! ! ! !! ! ! ! !!!!!!!!!!!! ! ! ! ! ! ! ! ! !!!!!!!! ! ! ! ! ! ! ! ! ! ! ! ! !! ! ! ! ! ! ! !!!! !! ! ! !!! ! ! ! ! ! ! ! ! ! ! ! !! ! ! ! ! ! ! ! ! !! ! !!! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !!! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !! ! ! ! ! ! !! !! !! !!!!!!!! !! ! !! !!!!! !! ! !! !! ! !! ! !!! ! !! ! ! !! ! ! ! !!! ! !! ! ! ! ! ! ! ! ! ! ! !! !!!! !!!!!!!!!!!!! !! !!! ! ! !! !! !! !!!! !!! !!!!! !! ! !! !! ! !!! !! !! !! ! ! ! !!!!!!! ! !! ! ! ! ! ! ! ! !! ! !! !!!!!!!!!! !!!!!!!!!!!!!!!! !!! !! ! !! !! !! !! !! !!! !! !! ! !! ! !! !!! ! ! ! ! ! !!!! ! ! ! ! !! ! !! !! ! !! ! !! ! !! !!! ! ! ! ! ! !!! !!!! !!!!!!!!! !!!!!!!!!! ! ! !!!!!!!! !! !!!! ! !!!!!!! ! ! ! ! ! !! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !!!!! !! ! ! !! ! ! ! ! ! ! ! ! ! ! ! ! !! ! ! ! ! ! ! !!!!!!!!!!!!!!!!!!!!!!!!!!!! ! !! ! ! ! ! ! ! ! !! !!!! ! ! ! ! !!! ! ! ! ! !! ! ! !! !
!!!!!!!!!!! ! ! ! ! ! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!! ! ! ! ! ! !!!! !!! !! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !!!!!!!!!!!!!!!!!! ! ! ! ! ! ! ! !! ! ! ! ! ! ! ! ! !!!! !!!!! ! ! ! ! ! ! ! ! ! ! !!!!!!!!!!!!!!! ! ! ! ! ! ! ! ! ! ! !!!!! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !!!!!!!!!
!!!!!!!!!!!!!!! !!!!!!!!!!!!! !!!!!!!!!!!!!!! !!!! ! !!! !!!!!!!!!!! !! !!!! !!!!!!!!!!!!!!! !!!! !! ! ! !! !! !! ! ! !!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!! ! !! !!! ! !!! !! ! !! ! ! ! ! !! !! !!! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !!! ! ! ! ! ! ! ! ! ! ! ! ! !!! ! ! ! ! !!!!! !!!!!!!!!!!!!! ! ! ! ! ! ! !!!!! ! ! ! !! ! ! ! !!! ! ! ! !! !! !! !!! !!!!!!!!! !! ! ! ! ! ! ! !! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !! ! ! ! !! ! !! ! ! ! !
!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !! ! !!! !! !! ! !!! ! !!!!! !! !!! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !!! !!!!!!! ! ! ! !!!!!!!! ! ! ! !! ! ! ! ! ! ! ! !! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !! ! !! ! ! ! ! !!! ! ! ! ! ! ! !! !
!!! !!!!
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!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !! !! !!!!!!!
!! !! !
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!!!!
!!!!!!!!!!!!!!!!!!!!!!!! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !! !
!!!!!!!!!!! ! ! ! ! ! ! ! ! ! ! !!
!!!!!! ! ! ! ! ! !!
!!!!!!!!!!!!! !!!! ! ! ! ! ! ! ! !!!!!!!!!!!!!! !! !! ! ! ! !!
Wav
e H
eigh
t (m
)
10%P
E in
50y
rs
!0
- 1
!1
- 2
!2
- 3
!3
- 4
!4
- 5
!5
- 6
!6
- 10
010
2030
405
km
Fi
g. 9
.3.5
.1
Tsun
ami W
ave
Hei
ght a
t the
Coa
st o
f 10%
PE
in 5
0 Ye
ars
76
10
12
34
0.5
km
Inund
atio
n D
epth
(m
)10
%P
E in
50y
rs
- 0.
5
0.5
- 1
1 - 2
2 - 3
3 - 4
4 - 5
5 - 6
Fig.
9.3
.5.2
Ts
unam
i Inu
ndat
ion
Dep
th a
t the
Sea
side
of 1
0% P
E in
50
Year
s – W
est -
77
10
12
34
0.5
km
Inund
atio
n D
epth
(m
)10
%P
E in
50y
rs
- 0.
5
0.5
- 1
1 - 2
2 - 3
3 - 4
4 - 5
5 - 6
Fig.
9.3
.5.3
Ts
unam
i Inu
ndat
ion
Dep
th a
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Sea
side
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E in
50
Year
s – E
ast -
78
10 ASSESSMENT OF SUITABILITY FOR SETTLEMENT
10.1 Technical and Legal Criteria of the Evaluation This evaluation of suitability for settlement was prepared according to 15 different Microzonation Maps,
which were produced regarding the technical specifications of this work, include each disaster hazard
evaluation. The Technical Specifications of this work and several standarts, regulations, circulars..etc that
implied in this spesification are technical purpose of the evaluation.
Regulations (by-laws) and circulars issued by the Ministry of Public Works and Settlement (MPWS) were
taken into account as criteria for the preparetion of suitability for settlement maps and reports belonging to
these maps. It was tried to stick to the size implied in circular which 31.05.1989 dated and 4343 numbered (no.
89/16) in this evaluation but, due to Microzonation maps are basis for this study and also this study is intensive
and very detailed, the Manuel for “Integration of Geo-scientific Data to Planning” prepared by the MPWS on
December 2006 was used.
10.2 Evaluation of Hazards in Terms of Settlement Suitability The following hazards were taken into consideration for the assessment of suitability for settlement
- Liquefaction hazard
- Landslide hazard
- Flooding Hazard (Tsunami Hazard included)
- Engineering problems (Filling, Tasman, Geological conditions, etc.)
After evaluating these hazards, base maps were prepared for each hazard and the Settlement Suitability
Maps were prepared from these base maps. Regarding the ground shaking intensity, there were discussions as
to whether or not it should be included as a factor for the settlement suitability.
As a result, the project area was basically divided into the following three (3) zones in terms of the
settlement suitability;
(a) Suitable Areas (UA)
(b) Precautionary Areas (ÖA)
(c) Unsuitable Areas (UOA)
In order to determine these areas from various hazards, each hazard was evaluated in terms of the land
suitability for settlement.
10.3 Suitable Areas (UA) Areas shown with “UA” in “Suitability for Settlement Maps” defined as “Suitable Areas for Settlement”.
These areas correspond to % 39,64 of the Project area.
In these areas;
- There are zones with Trakya, Ceylan, Gürpınar Formations, units belonging to Bakırköy
79
Member and units belonging to Güngören Member geologicly.
- Morphologicly there are no obstackles against settlement.
- There is no risk for liquefaction or ground amphilication.
- Lanslide or similar mass movements were not developed.
- There is no Tsunami or Flooding hazards.
- These areas are suitable for structuring in terms of Foundation Engineering.
There may be some local problems even if these areas are suitable for settlement. Therefore, these possible
local problems should be determined in lot – based studies with presentation of solution suggestions and
implementation projects should be conducted with taking these items into account. In deep drillings conducted
for proccess of the work, there should be stability problems because of wedge type slips due to dense fractured
structure of rocks and clay, silt or sand lens contained areas. In these type of areas some special measures
should be taken and adequate projects should be prepared.
10.4 Precautionary Areas (ÖA) Areas shown with “ÖA” in “Suitability for Settlement Maps” defined as “Precautionary Areas”. These
areas correspond to % 58,94 of the Project area. These areas have items like natural disaster hazards and
geologic-geotechnic characteristics that may effect areas in terms of suitability for settlment so, planning and
structuring for these areas is possible with taking some measures before or during structuring. Liquefaction,
landslide, tsunami, flooding and engineering problems (ground amplification, bearing capacity, settlement,
swelling, tasman, rock fall..etc.) may be seen individualy or together in these areas. Precautionary Areas (ÖA)
were divided into sub-titles regarding to the problems that were occured and/or possible to occure. These areas
are;
- Precautionary Area 1 (ÖA1) : in terms of Liquefaction Hazard
- Precautionary Area 2 (ÖA2): in terms of Stability Hazard
- Precautionary Area 3 (ÖA3) : in terms of Tsunami and Flooding Hazard
- Precautionary Area 4-5 (ÖA4 - ÖA5) : in terms of Engineering Problems
- Precautionary Area 4 (ÖA4): In terms of Artificial Filling and Alluvium Areas
- Precautionary Area 5 (ÖA5) : In terms of Rock Fall, Tasman Hazard and Mine areas.
- Precautionary Area 6 (ÖA6): Multiple hazard possiblity (Complex problems) areas.
Also, precationary areas sub-divided into 2 regions regarding to the variaty and desity of problems and
measures for these problems;
- ÖA(a) : Primary Precautionary Areas
- ÖA(b) : Secondary Precautionar yAreas
10.4.1 Precautionary Areas -1 These are the areas with liquefaction hazard. In case of evaluation of liquefaction hazard in terms of
80
suitability for settlement, each factor should be investigated regarding to damage on buildings or ground. One
of these factors is ground settlement deformation due to liquefaction. Suitability for settlement can be
estimated by ground deformation level.
As a result, precautionary areas in terms of liquefaction hazard were divided into two sub-section as
“ÖA-1(a)” and “ÖA-1(b)”.
10.4.1.1 Precautionary Areas-1(a); ÖA1(a)
These areas are zones which include quaternary aged, grainy and terrestrial based alluvial deposits and sea
- based soft grounds in coasts.
In these areas;
- Liquefaction potential is high,
- Silt, clay and gravel layers are existed ,
- Groundwater is too close to surface, ,
- There is a risk for ground amplification,
- There are infirm (soft) grounds in terms of foundation engineering,
- Groundwater and stability problems may occure in foundation digs.
- 10-30cm of settlements are expected according to analysis results.
- Ground damages like small cracks, sand leakages..etc are expected.
10.4.1.2 Precautionary Areas-1(b); ÖA1(b)
These areas are zones which include quaternary aged, grainy and terrestrial based alluvial deposits and sea
- based soft grounds in coasts.
In these areas,
- Liquefaction potential is low,
- There are layers with clay, silt, sand and gravel.
- Groundwater is close to the surface,
- There is a risk for ground amplification
- There are infirm (soft) grounds in terms of foundation engineering,
- Groundwater and stability problems may occure depending thickness of soft material in foundation digs
- 10-30cm of settlements are expected according to analysis results,
- Ground damages like small cracks..etc are expected.
10.4.2 Precautionary Areas-2
These are the areas with mass movements that may occure in some circumstances (Landslide).
Precautionary areas in terms of mass movements were divided into 2 sub-section as “ÖA-2(a)” and “ÖA-2(b)”
10.4.2.1 Precautionary Areas-2(a): ÖA2(a) These are the areas that include Gürpınar and Güngören members, can be found in high inclination slopes
81
with serious stability problems. Areas with present safety factor estimated as (1.0 < Fs ≤2.0) from conducted
analysis were evaluated in this group.
These areas ;
- Consist of clay, silt and sand under these materials,
- Have inclination that may effect stability negatively,
- Have groundwater problem,
- Have possibility of slip surfaces that effect stability may be deeper than 10m of depth.
10.4.2.2 Precautionary Areas-2(b): ÖA2(b) These are the areas that include Gürpınar and Güngören members, can be found in high inclination slopes
with medium-high stability problems.
These areas,
- Consist of clay, silt and sand under these materials
- Have inclination that may effect stability negatively
- Have groundwater problem
- Slip surfaces that effect stability are between 3-10m of depth
10.4.3. Precautionary Areas-3 These areas have flooding possibility in case of an earthquake. These areas are mostly close to coasts,
valleys intersected with a coastal and Haliç (Golden Horn) connected to sea and lake shores.
These areas are divided into 2 subsections as “ÖA3(a)” and “ÖA3(b) according to possible wave hight.
10.4.3.1. Precautionary Areas-3(a): ÖA3(a) These are areas where the tsunami height or inundation depth is expected to be between 3m ≤ HW <10m.
Actually there is no such zone in the project area.
10.4.3.2 Precautionary Areas-3(b): ÖA3(b) These are areas where the tsunami height or inundation depth is expected to be between 0m < HW < 3m
Because of medium-low flooding hazard, special measures should be taken such as evacuation plans (routes,
places, or notification system). Also, advises should be taken from related departments (ISKI,DSI..etc) for
planning against possible floodings that may occure in valleys or other flood vulnerable areas depending on
participation.
10.4.4 Precautionary Areas-4 and Precautionary Areas-5
These are areas with some engineering problems such as Alluvium areas, artificial fillings, tasman, rock
falls, and cave-in of mines.
These areas were divided into 4 subsections as “ÖA4(a), ÖA4(b), ÖA5(a) and ÖA5(b)“ in terms of
engineering problems and level of the measures to be taken.
82
10.4.4.1. Precautionary Areas-4(a): ÖA4(a) These areas have major engineering problems such as very thick alluvium and very thick artificial fillings ,
etc. Actually there is no such zone in the project area.
10.4.4.2. Precautionary AReas-4(b): ÖA4(b)
These areas represented by alluvium and artificial fillings. Thichness and distributions of these artificial
fillings in these areas should be determined before construction because these fillings do not considered as
carrier. Therefore, in construction phase, the foundation of buildings should be put on stable grounds.
10.4.4.3. Precautionart Areas-5(a): ÖA5(a)
These are areas with major engineering problems such as tasman, rock falls, cave-in of mines, etc. Actually
there is no such zone in the project area.
10.4.4.4. Precautionary AReas-5(b): ÖA5(b) These areas represented by rock fall hazard areas, tasman areas and mine areas. These areas includes step
rock slopes, underground karstic gaps in some parts of the study area. Wedge type of slips may occure in rock
environments, deep drillings and steep slopes. Tasman may occure in Bakırkoy region because of karstic gaps.
10.4.5. Precautionary Areas-6 These are areas with multiple problems like liqufaction, flooding, mass movements and engineering
problems. These areas divided into 2 subsections according to levels of problems and measures.
10.4.5.1 Precautionary Area-6(a): ÖA6(a) These areas have more than one of the above problems with one of these problems has 1.level (a) of
importance. Detailed studies should be conducted before implementation and measures to take should be
determined.
10.4.5.2 Precautionary Areas-6(b): ÖA6(b) These areas have more than one of the above problems with one of these problems has 2.level (a) of
importance. Detailed studies should be conducted before implementation and measures to take should be
determined.
10.5 Unsuitable Areas (UOA) Unsuitable Areas (UOA) are defined in Table 10.5.1 with taking previous evaluations of related hazards
into account. This area should not be planned and opened to the settlement due to some high hazard
possibilities in terms of suitability of settlment. Avcılar Ambarlı Balaban District, Denizköşkler Districkt,
Bakırköy Menekşe District, lake slopes in east part of Firuzköy and Halkalı garbage dump area are inside of
this area.
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Table 10.5.1 Definition of “UOA” (Unsuitable Areas)
Area Category Descriptions
UOA
(Unsuitable Area)
Areas which are assigned to the highest hazard and assigned to UOA area for at
least one of the following hazard items:
(1) Liquefaction Hazard (Very soft ground areas like swamp..etc.)
(2) Landslide Hazard
(3) Flooding Hazard
(4) Engineering Problems
These areas were divided into 4 subsections according to source of the problem. There is no area with
Liquefaction hazard (UOA1) or Flooding hazard (UOA3) in Project area. Unsuitable Areas correspond
to %1,42 of Project area.
10.5.1 Unsuitable Areas-2: UOA-2 These areas have active mass movements and determined as active landslide areas in previous studies in
Project area. These areas should not be planned and opened to the settlement.
10.5.2 Unsuitable Areas-4: UOA-4
These areas are thick artificial filling areas in Project area. These areas should not be planned or opened to
settlement because of their thickness of fills and physical-chemical characteristics. Halkalı garbage dumb
should be considered in this group in Project area.
Detailed characteristics of problems and evaluations of analysis that suitability for settlement groups have,
can be found in related section.
Unsuitable areas should not be planned for structuring and parcel-based, detailed Ground Survey Works
should be conducted for every other areas.
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11 RESULTS AND SUGGESTIONS (1) PRODUCTION OF SETTLEMENT PROPOSED MICROZONATION REPORT AND MAPS –
EUROPEAN SIDE (SOUTH)” work which belongs to Istanbul City, European Side (South) was
conducted by OYO International Corporation on behalf of The Istanbul Metropolitan Municipality (IMM).
Geological, geotechnical, geophysical characteristics of the Work area were identified and the data were
analyzed.
(2) Total 16 microzonation hazard maps were produced as implied in technical spesificaiton of this work.
Also, extra 11 contributing and correlation maps were created. As a result of these maps and evaluation of
risks reffered in these maps, 1/2000 scale “Settlement Suitability Maps” were produced.
(3) Total 2830 normal drillings with 30m depth, 27 deep drillings with 80-250m depth, 764 liquefaction
drillings with 20m depth, 608 landslide drillings with 30m depth, 100 drillings with differant depths to
determine baserock depth and thickness of some formations and also 35 drillings to determine some
structural features like faults and alluvium thickness as a total number of 4364 mechanical drillings were
conducted in 2912 grids (250x250) within the context of project and total drilling depth was reached to
125578,90m. Beside SPT tests which were conducted in field, 636 CPT tests were also conducted. 2762
Siesmic Refraction – ReMi measurements, 2625 Electric Resistivity measurements, 201 PS Logging tests,
Array Microtremor measurement in 30 points and 20km lenght Seismic Reflection measurement were
conducted within the context of geophysical studies.
(4) Work area is in regions that contain differant earthquake risks according to Turkey Earthquake Regions
Map. Considering strong ground movements contained from last earthquake and accelerations and also
according to Probabilistic Earthquake Hazard Maps preapered in this work and geological-geophysical,
geomorphologic and techtonic charactersitics of the study area, informations about previous earthquakes
and existing earthquake hazard maps should be reviewed and updated.
(5) Active landslides were observed in Menekşe District, Balaban District, slopes of east side of Küçükçekmece Lake (Firuzköy) and Denizköşkler District in Project area These areas were evaluated as unsuitable areas for settlement. There is a 28/06/2005 dated and 9109 numbered Cabinet Decision Disaster Effected for Avcılar Ambarlı District. Rock fall or avalanche risk do not existed in Project area other than this one. Opinion of DSI (ISKI) should be taken for water courses in Project area before planning.
(6) The project area was basically divided into three (3) zones as Suitable Areas (UA), Precautionary
Areas (ÖA) and Unsuitable Areas (UOA) in terms of the settlement suitability;
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Suitable Areas (UA)
In these areas there are zones with Trakya, Ceylan, Gürpınar Formations, units belonging to Bakırköy
Member and units belonging to Güngören Member geologicly.
Precautionary Areas (ÖA)
These areas have items like natural disaster hazards and geologic-geotechnic characteristics that may
effect areas in terms of suitability for settlment so, planning and structuring for these areas is possible
with taking some measures before or during structuring. Precautionary Areas (ÖA) were divided into
sub-titles regarding to the problems that were occured and/or possible to occure. These areas are;
- Precautionary Area 1 (ÖA1) : in terms of Liquefaction Hazard
- Precautionary Area 2 (ÖA2): in terms of Stability Hazard
- Precautionary Area 3 (ÖA3) : in terms of Tsunami and Flooding Hazard
- Precautionary Area 4-5 (ÖA4 - ÖA5) : in terms of Engineering Problems
- Precautionary Area 4 (ÖA4): In terms of Artificial Filling and Alluvium Areas
- Precautionary Area 5 (ÖA5) : In terms of Rock Fall, Tasman Hazard and Mine areas.
- Precautionary Area 6 (ÖA6): Multiple hazard possiblity (Complex problems) areas.
Also, precationary areas sub-divided into 2 regions regarding to the variaty and desity of problems
and measures for these problems;
- ÖA(a) : Primary Precautionary Areas
- ÖA(b) : Secondary Precautionar yAreas
Unsuitable Areas (UOA)
This area should not be planned and opened to the settlement due to some high hazard possibilities in
terms of suitability of settlment. Avcılar Ambarlı Balaban District, Denizköşkler Districkt, Bakırköy
Menekşe District, lake slopes in east part of Firuzköy and Halkalı garbage dump area are inside of
this area
(7) It is necessary to conduct lot-based Ground Survey studies before implementation for new constructions.
(8) This study is a Construction Plans Based “Geological-Geotechnical Survey Study Regarding to
Settlement Purposed Microzonation Works” that can not be used as lot-based (parcel-based) Ground
Survey study.
