Survey Report on the Areas Affected by the
Earthquake with Epicenter in Southeastern
TurkeySchool of Architecture, Mukogawa Womenʼs University, Japan
Shigeyuki Okazaki, Dean, Professor
Kazuhiko Yanagisawa, Head of Architecture Department, Professor
Shigeki Tosu, Professor
Hiroyuki Tagawa, Professor

Kobe City, Japan
Yukio Tanaka, Executive Director, Building Guidance Department,
Construction and Housing Bureau

Masayoshi Nose, Director, Crisis Management Office

August 2023
* English translation of the Japanese version (May 2023)

57

Preface

On February 6, 2023, there was a major earthquake in the areas straddlingsoutheastern Turkey and Syria. In fact, there was also a severe earthquake in 2011 in thevicinity of Lake Van, which is located to the east of the affected area. After the Van
earthquake, myself, two Kobe City officials, one former Kobe City official, and one
structural researcher from E-Defense conducted a field survey of the damage with then
Dean of the Faculty of Architecture and Design Ahmet Eyüce and Professor Murat
Dündar of Bahçeşehir University in Istanbul. After the survey, we held a public symposiumin Istanbul. Mukogawa Women's University signed an exchange agreement with
Bahçeşehir University in 2008, and the schools of architecture at both universities haveconducted short-term exchange programs almost every year, as well as jointly hosting
the International Conference on Archi-Cultural Interactions through the Silk Road.
Again, immediately after the earthquake, we were in contact with Professor Murat
Dündar, the current Dean of the Faculty of Architecture and Design at Bahçeşehir
University, who provided us with comparative photos of historical and cultural buildings
and townscapes before and after the earthquake, as well as topographical maps of theentire affected area. Subsequently, at the invitation of Bahçeşehir University, we decided
to conduct a survey of the affected areas together with the City of Kobe.
On April 12, three professors from the School of Architecture at Mukogawa Women's
University and two Kobe City officials left for Turkey to survey earthquake disasters insoutheastern Turkey. On the 11th, the day before their departure, a press conference washeld in Kobe City. The three members from Mukogawa Women's University were
Professor Yanagisawa, head of the architecture department and a professor ofarchitectural design, Professor Tagawa, a professor of earthquake-resistant engineering,and Professor Tosu, a professor of structural design, while the two members from Kobe
City were Executive Director Tanaka of the Construction and Housing Bureau andDirector Nose of the Crisis Management Office. Professor Murat Dündar planned thesurvey cities and itinerary, and guided them throughout the entire tour.
With the full support of Bahçeşehir University, the group flew to the affected areas
early in the morning of the day after their arrival in Istanbul, conducted surveys in
Kahramanmaraş, Hatay, and other areas that were most severely damaged, and after
returning to Istanbul, held a press conference and exchanged opinions with researchers
from Bahçeşehir University. The five returned to Japan on April 20, and held a debriefing
session at the West Hall of Mukogawa Women's University Koshien Hall on May 1,
inviting TV stations and newspapers.

1

The three reporters were from Mukogawa Women's University and two from Kobe City.
And Prof. Murat Dündar participated online. The entire cost of the research in Turkey was
supported by Bahçeşehir University. Travel expenses for all participants from Mukogawa
Women's University were supported by Hyogo Prefecture.
Prof. Yanagisawa reported on the overall damage, Prof. Tagawa on the magnitude andcharacteristics of the earthquake and the damage, Prof. Tosu on the damage caused by
the form of buildings and their relationship with adjacent buildings from a structuraldesign perspective, and Mr. Tanaka and Mr. Nose of Kobe City on the importance ofbuilding administration in dealing with earthquake damage and their visits to the mayors
in the affected areas. Dean Murat reported on the problems of the inspection system forarchitectural design and renovation work in Turkey, and on the plan to open a disasterprevention center at Bahçeşehir University.

Prof. Dr. Shigeyuki Okazaki
Dean of the School of Architecture
Mukogawa Womenʼs University

2

Table of Contents

１．Overall Overview ........................................................................................................................................... 5
１-１．Members .............................................................................................................................................. 5
１-２．Dispatch Schedule .............................................................................................................................. 5
１-３．Survey Summary ................................................................................................................................. 6
１-３-１．Apr. 14 (Fri.) Adana and Kahramanmaraş Provinces ........................................................... 7
１-３-２．Apr. 15 (Sat.) Antakya and Samandağ Districts, Hatay Province ..................................... 10
１-３-３．Apr. 16 (Sun.) İskenderun and Payas Districts, Hatay Province ....................................... 17
１-３-４．Apr. 17（Mon.）Roundtable at Bahçeşehir University ...................................................... 20
２．SURVEY REPORT I Seismic Intensity and Observed Damage :From a Perspective of Seismic Structure....... 21
２-１．Adana Province .................................................................................................................................. 21
２-２．Kahramanmaraş Province ................................................................................................................ 25
２-３．Hatay Province .................................................................................................................................. 31
２-４．Collapse Mechanism and Prevention ............................................................................................ 37
３．SURVEY REPORT Ⅱ

Specific Building Forms and Damage Conditions :From a Perspective of Structural Design ....... 39

３-１．Introduction ........................................................................................................................................ 39
３-２．The Impact of Adjacent Building Spacing on the Expansion of Seismic Damage .................. 39
３-３．The Commercial Use of Lower Levels in Mid-Rise and High-Rise Buildings
and its Relationship to Seismic Damage .... 39
３-４．The Unreinforced Masonry Infill Walls in RC Buildings and Seismic Damage ........................ 40
３-５．The Qualification System for Structural Designers in Turkey
and Current Seismic Design Codes ..... 41
３-６．Others ................................................................................................................................................. 42
４．SURVEY REPORT Ⅲ

Visits to Mayors of the Affected Municipalities
and Tours of Tents and Container Temporary Housing, etc. .... 43

４-１．Results of Hearing with Mayors of the Affected Municipalities ................................................ 43
４-２．Tours of Tents and Container Temporary Housing, etc. .............................................................. 44
４-２-１．Beyoğlu Disaster Relief Center in Kahramanmaraş Dulkadiroğlu ................................... 44
４-２-２．Tent Village in İskenderun Provided by the National Government,
Municipalities, and Turkish Red Crescent, etc. ............ 44
４-２-３．Container Temporary Housing, etc. in Payas ...................................................................... 45
５．SURVEY REPORT Ⅳ

Status of Damage to Historic Buildings ......................................................... 47

５-１．Kahramanmaraş Ulu Camii .............................................................................................................. 47
５-２．Other Major Historical Buildings .................................................................................................... 50

3

６．Recommendations Based on the Survey Reports ................................................................................. 52
７．List of Media Coverage ............................................................................................................................. 55
７-１．Turkey ................................................................................................................................................... 55
７-２．Japan ..................................................................................................................................................... 56
Acknowledgments【Special Contribution】
Problems that increased the destruction caused by the Kahramanmaraş-centered earthquake .......... 57

Prof. Dr. Murat Dündar (Dean of Faculty of Architecture & Design, Bahçeşehir University)4

１．Overall Overview
On February 6, 2023, an earthquake centered in southeastern Turkey caused extensive
damage in the region and surrounding areas. At the request of Bahçeşehir University inTurkey, three faculty members with expertise in architectural structure and design from
Mukogawa Women's University (MWU), which has a general exchange agreement with
Bahçeşehir University, and two officials in charge of architectural guidance and crisis
management from Kobe City, which experienced the Great Hanshin-Awaji Earthquake,were sent to the affected areas to conduct on-site surveys for reconstruction.
１-１．Members
Japan Side PlannerProf. Dr. Shigeyuki Okazaki, Dean, School of Architecture, MWU
Dispatch Members
Prof. Dr. Kazuhiko Yanagisawa, Head of Architecture Department, School of Architecture, MWU(Architectural Design and Planning)

Prof. Dr. Shigeki Tosu, School of Architecture, MWU (Architectural Structure Design)
Prof. Dr. Hiroyuki Tagawa, School of Architecture, MWU (Architectural Structure Engineering)
Mr. Yukio Tanaka, Executive Director, Building Guidance Department,
Construction and Housing Bureau, Kobe City

Mr. Masayoshi Nose, Director, Crisis Management Office, Kobe City
１-２．Dispatch Schedule
Dispatch period: April 12 (Wed.) - April 20 (Thu.)
Date

Contents

Place to stay

Apr. 12 (Wed.)

Departure from Japan

Apr. 13 (Thu.)

Visit to Bahçeşehir Universityİstanbul

Apr. 14 (Fri.)

Visit to the Mayor of Çukurova, Adanaİskenderun

Visit to the Mayor of Onikişubat, Kahramanmaraş
Visit to Onikişubat and Dulkadiroğlu, Kahramanmaraş
Apr. 15 (Sat.)

Visit to Antakya, Hatayİskenderun

Visit to the Hatay Metropolitan Municipality Mayor
Visit to Samandağ, Hatay
Apr. 16 (Sun.)

Visit to İskenderun, Hatayİstanbul

Visit to the Mayor of Payas, Hatay
Tours of temporary housing, etc in Payas, Hatay
Apr. 17 (Mon.)

Roundtable at Bahçeşehir Universityİstanbul

Apr. 18 (Tue.)

Visit to İstanbulİstanbul

Apr. 19 (Wed.)

Departure from İstanbul

Apr. 20 (Thu.)

Arrival in Japan5

１-３．Survey SummaryFig. 1-1

Location of epicentersFig. 1-2

Destinations

On April 14 (Fri.), we arrived in Adana from İstanbul, visited Adana, Kahramanmaraş,and Hatay provinces, and returned to İstanbul on April 16 (Sun.) On April 17 (Mon.), at
Bahçeşehir University, with the presence of local media, we provided information on thehistory and efforts of architectural structures in Japan, and on the efforts of Kobe City,
which experienced the earthquake, and opinions were exchanged on this earthquake.

6

１-３-１．Apr. 14 (Fri.) Adana and Kahramanmaraş Provinces

Photo 1-1

Visit to the Mayor of Çukurova, Adana.

Photo 1-２

Visit to the Mayor of Onikişubat, K.Maraş.

Photo 1-3

Onikişubat, K.Maraş. Drone shot of container temporary housing. The white building in the back infront is the district office building.

Photo 1-4 Onikişubat, K.Maraş.

Photo 1-5 Onikişubat, K.Maraş.

Peeling of exterior walls of apartment buildings.

7

Drone shot of apartment buildings in Photo 1-4.

Photo 1-6 Onikişubat, K.Maraş.

Photo 1-７Onikişubat, K.Maraş.

Three 10-story buildings were destroyed.

Opposite side of photo 1-6.

Debris has already been removed in many places.

in the apartment building in the back.

Photo 1-8 Onikişubat, K.Maraş.

People were living

Photo 1-9 Onikişubat, K.Maraş.

HACI HUSEYIN KARA CAMARA CAMII.

HACI HUSEYIN KARA CAMARA CAMII.

The building next door collapsed and damaged the Camii.

Shot from above by drone.

Photo 1-10 Onikişubat, K.Maraş. Hz. Yunus Cami. Collapse of minarets.

8

Photo 1-11 Dulkadiroğlu, K.Maraş. Drone shot of Ulu Camii.
The building below was damaged by the minaret breaking and falling stones.

Photo 1-12 Dulkadiroğlu, K.Maraş.
Falling exterior wall blocks.

Photo 1-14 Dulkadiroğlu, K.Maraş.

Photo 1-13 Dulkadiroğlu, K.Maraş. The government building
can be seen in the back. Buildings were lost in large areas.

Photo 1-15 Dulkadiroğlu, K.Maraş.

Building demolition site.

Beyoğlu Disaster Relief Center.

9１-３-２．Apr. 15 (Sat.) Antakya and Samandağ Districts, Hatay Province

Photo 1-16 Antakya, Hatay. The town was devastated and the military was in charge of the town. Only locals wereallowed to enter, and we were given special permission to inspect the site. The famous Hatay
Archaeology Museum was sealed off and could not be seen.

Photo 1-17 Antakya, Hatay. Former Parliament building. Photo 1-18 Antakya, Hatay.
Hatay Devleti döneminde meclis binası.

Photo 1-19 View of the town of Antakya, Hatay.

Ruins of Hatay Metropolitan Municipality Office Building.

Photo 1-20 View of the town of Antakya, Hatay.

10

Photo 1-21 Antakya, Hatay. Ulu Cami.

Photo 1-22 Antakya, Hatay.

Photo 1-23 Antakya, Hatay.

Ulu Cami's gate shopping area.

Photo 1-24 Antakya, Hatay.
Hürriyet Street.

Hürriyet Street buried under rubble.

Photo 1-25 Antakya, Hatay.
View of Hatay City Museum from the other side of the river.

11

Photo 1-26 Antakya, Hatay.

Photo 1-27 Antakya, Hatay.

The seven-story townscape was gone.

Photo 1-28 View of the town of Antakya, Hatay.

Peeling of bridge finishing materials.

Photo 1-29 View of the town of Antakya, Hatay.

Photo 1-30 View of the town of Antakya, Hatay.

Photo 1-31 Antakya, Hatay.
Greek Orthodox Church Gate Street.

Photo 1-32 Antakya, Hatay.

Photo 1-33 Antakya, Hatay.

Greek Orthodox Church Gate Street.

Greek Orthodox Church Gate Street.

12

Photo 1-34 Antakya, Hatay. Greek Orthodox Church.

Photo 1-35 Antakya, Hatay. Greek Orthodox Church.

Photo 1-36 Antakya, Hatay.
ANTİK BEYAZIT HOTEL in a restored 1903 building.

Photo 1-37 Antakya, Hatay.

Photo 1-38 Antakya, Hatay.

Özel Antakya Ata Koleji, a building from 1908.

Government building.

13

Photo1-39 Antakya, Hatay.

Photo 1-40 Antakya, Hatay.

Protestant Church.

There was also an intact hotel.

Photo 1-41 Antakya, Hatay. Kurtuluş street.

Photo 1-42 Antakya, Hatay.

Photo 1-43 Antakya, Hatay.

Alley entering from Kurtuluş Street.

Sarımiye Camii

14

Photo 1-44 Antakya, Hatay. Habib-i Neccar Camii.

Photo 1-45 Antakya, Hatay.

Photo 1-46 Antakya, Hatay.

Hatay Sanayici ve İş İnsanları Derneği（HASiAD）

Photo 1-47 Antakya, Hatay.

Mahremiye Camii.

Photo 1-48 Visit to the Hatay Metropolitan Municipality Mayor

Uzun Çarşı

15

Photo 1-49 Samandağ, Hatay. Many buildings collapsed or damaged.

Photo 1-50 Samandağ, Hatay.

Photo 1-51 Samandağ, Hatay.

Site where an extension building collapsed.

This was originally a six-story apartment building.
The first and second floors were crumbling.

Photo 1-52 Samandağ, Hatay. Photo from another angle.
Originally bordered by the neighboring building.

16

Photo 1-53 Samandağ, Hatay.
A building whose layers were collapsing.

１-３-３．Apr. 16 (Sun.) İskenderun and Payas Districts, Hatay Province

Photo 1-54 İskenderun, Hatay. Greek Orthodox Church

Photo 1-55 İskenderun, Hatay. Liquefaction.

Photo 1-56 İskenderun, Hatay.
Some are living on the military ship as evacuees.

Photo 1-57 İskenderun, Hatay.

Photo 1-58 İskenderun, Hatay.

Peeling of exterior walls of apartment buildings.

In the back, a 12-story apartment building collapsed.

17

Photo 1-59 İskenderun, Hatay. Collapsed site of a 12-story apartment building.

Photo 1-60 İskenderun, Hatay.

Photo 1-61 İskenderun, Hatay.

Apartment buildings to be demolished.

Photo 1-62 İskenderun, Hatay.

Fissures in the groundPhoto 1-63 İskenderun, Hatay.

A 9-story apartment building collapsed.

A 7-story apartment building collapsed. The columns of the

4-story buildings are safe.

restaurant on the first floor had been removed by the owner.

18

Photo 1-64 İskenderun, Hatay. Tent village.

Photo 1-65 İskenderun, Hatay. Tent village.
Residential Tent.

Photo 1-66 İskenderun, Hatay.

Photo 1-67 Visit to the Mayor of Payas, Hatay.

İSKENDERUN STATE HOSPITAL

Photo 1-68 Payas, Hatay.

Photo 1-69 Payas, Hatay.

Sokullu Mehmet Paşa Külliyesi

Container temporary housing under construction.

Photo 1-70 Payas, Hatay.

Photo 1-71 Payas, Hatay.

Container temporary housing currently in use.

19

Field hospital provided by Qatar.

１-３-４．Apr. 17（Mon.）Roundtable at Bahçeşehir University

Photo 1-72 Prof. Dr. Murat Dündar,

Photo 1-73 Prof. Dr. Kazuhiko Yanagisawa,

being interviewed by TV station.

Photo 1-74 Executive Director Yukio Tanaka,

being interviewed by TV station.

Photo 1-75 A commemorative photo with paper cranes

being interviewed by TV station.

in everyone's hands

Photo 1-76 A roundtable was held at Bahçeşehir University with the presence of local media. In addition to providing
information on the history and efforts of architectural structures in Japan and the efforts of Kobe City, which
experienced the earthquake, we exchanged opinions on this earthquake. We also discussed how the Disaster
Prevention Center, which is scheduled to be newly established at Bahçeşehir University, should be established.

20

２．SURVEY REPORT I

Seismic Intensity and Observed Damage：From a

Perspective of Seismic Structure
The seismic damage of structures is determined by seismic intensity, demand, and theseismic performance of structures, capacity. In this chapter, the seismic intensity in thethree provinces, Adana, Kahramanmaras, and Hatay, as well as the observed seismic
damage in the three provinces, are described. The geographical positions of theseprovinces, Adana, Kahramanmaras, and Hatay, are illustrated in Fig. 2-1. This figure
presents the epicenter and fault line of the initial earthquake, transpiring at 4:17 a.m.
(local time) on February 6, 2023. The figure symbolizes the observation stationʼs location
with the triangular symbol (△), which is color-coded to indicate the range of maximum
ground motion acceleration. The observation stations marked with pink (△) exemplify
ground motions with a maximum acceleration exceeding 300 gal and are situated in
proximity to, and along, the fault line.

Fig. 2-1 Locations of three provinces visited and surveyed

２-１．Adana Province
The ground motion intensity recorded and seismic damage observed in the province ofAdana are described. Fig. 2-2 illustrates the observation stations situated within theurban area of Adana. Two stations, namely TK0118 and TK0123, are depicted. The groundmotion recorded at TK0118, situated close to the Cukurova municipal office, which we

21

visited, has been utilized. The time-history of ground accelerations (in the east-west,
north-south, and up-down directions) is presented in Fig. 2-3. The maximum groundaccelerations are 38.2 gal in the east-west direction, 49.7 gal in the north-south direction,and 23.3 gal in the up-down direction. Although it might be reasonable to convert andrepresent pulse-type near-fault ground motions in the strike-normal direction,
perpendicular to the fault line, and in the strike-parallel direction, the data in the eastsouth and north-south directions is displayed in this report. The instrumental seismic
intensity, as defined by the Japan Meteorological Agency, is 4.0. It should be noted thatthe instrumental seismic intensity for TK0123 is 3.7.
To express the impact of ground motions on the seismic response of structures, theresponse spectrum is typically employed. Ground motions are input into single-degreeof-freedom oscillator models with varying natural periods, consisting of one mass, one
spring, and one dashpot, and the maximum values of acceleration, velocity, anddisplacement responses are computed and plotted against the natural period. The
maximum values of the time-history response are computed with single-degree-offreedom oscillator models with natural periods ranging from 0.04 to 3.0 seconds, with aviscus damping ratio of 5%, and subjected to the TK0118 ground motion acceleration.
The acceleration, velocity, and displacement spectra in the horizontal and verticaldirections are presented in Fig. 2-4. In this figure, the values of the response spectra in
the horizontal direction are derived as the maximum value of the square root of the sumof the squared responses in the east-west and north-south directions at each time step.
Additionally, the response spectra for the JMA-Kobe ground motions recorded during the
1995 Hyogo-ken Nunbu Earthquake are provided for comparison. Notably, theinstrumental seismic intensity of the JMA-Kobe ground motions measures 6.4. The
acceleration, velocity, and displacement spectra for TK0118 are evidently smaller thanthose of the JMA Kobe ground motions.
Fig. 2-5 presents the demand response spectra, known as the Sa-Sd plot, where thedisplacement response spectra (Sd) is plotted on the X-axis, and the acceleration
response spectra (Sa) is plotted on the Y-axis. Here, the viscous damping ratio is also
set to 5%. If the load-displacement curve, known as the capacity spectrum, of thesubstitute single-degree-of-freedom oscillator model is plotted over the Sa-Sd plot, theseismic performance of a structure can be quickly assessed. This methodology,
recognized as the Capacity Spectrum Method (CSM), forms the foundation for
calculating the response and limit strength using the substitute linearization method. It
is noteworthy that the Substitute Structure Method was originally proposed in the paper
by Gulkan and Sozen (1974), and Polat Gulkan, the author of the paper, is a renowned
seismic engineering researcher from Turkey.

22

Fig. 2-2 Observation stations in Adana urban area100

max：38.2gal

50
0
-50
-100

east-west
0

20

40

60

80

100

120

140

Time (s)100

max：49.7gal

500north-south

-50
-100

0

20

40

60

80

100

120

140

Time (s)100

max：23.3gal

50
0

up-down

-50
-100

0

20

40

60

80

100

120

140

Time (s)blue: JMA-kobe
red: TK0118

2
1.5
1
0.5
0

0

1

2

3

Natural Period T(s)3

Acceleration

2.5
2
1.5

blue: JMA-kobe
red: TK0118

1
0.5
0

0

1

2

Natural Period T(s)3

Velocity

300
200
100
0

0

1

2

3

Natural Period T(s)(a) Horizontal direction

400

Velocity
300
200
100
0

0

1

2

Natural Period T(s)3

Horizontal Displacement Response (cm

2.5

400

Vertical Displacement Response (cm)Acceleration

Horizontal Velocity Response (cm/s)

3

Vertical Velocity Response (cm/s)

Vertical Acceleration Response (g)Horizontal Acceleration Response (g)Fig. 2-3 Time-history of ground acceleration (TK0118)
60

Displacement

50
40
30
20
10
0

0

1

3

60

Displacement

50
40
30
20
10
0

0

1

2

Natural Period T(s)(b) Vertical direction
Fig. 2-4 Acceleration, velocity, displacement response spectra (TK0118)

23

2

Natural Period T(s)33
Teff=0.5s

2.52

Teff=1.0s

1.5
1.5s

1

2.0s

0.5
0

2.5s
3.0s

0

10

20

30

40

50

60

Sd(cm)
Fig. 2-5 Demand response spectra (TK0118)

The seismic damages observed in the urban area of Adana are presented in Photo 21. This photograph captures the vicinity of the Cukurova municipal office, where
numerous reinforced concrete (RC) high-rise apartment buildings line the main road.
Cracks are discernible on the exterior walls of many buildings, constituting non-structural
damages. Additionally, there is evidence of a partial eave collapse. However, during acursory inspection of the urban area from a moving vehicle, no instances of building
collapse resulting from the earthquake were observed. Nevertheless, as per a
conversation with the headman of Cukurova and a news report from Japan, it has cometo light that a 14-story RC apartment building suffered complete collapse as aconsequence of the earthquake, as shown in Photo 2-2. Moreover, approximately 12 RC
high-rise apartment buildings in Cukurova have also collapsed, which poses a criticalissue. The precise locations of these collapsed apartment buildings have not been
specified, making it challenging to accurately determine the intensity of the groundmotions they were subjected to. However, presuming that the instrumental seismic
intensity of the TK0118 and TK0123 observation stations in the Adana urban area is 3.7
and 4.0, respectively, a similar level of intensity can be inferred for these apartmentbuildings. It is postulated that critical design flaws contributed to the total collapse of thehigh-rise apartment buildings under this intensity level of ground motions.

Photo 2-1 Seismic damage in Adana

Photo 2-2 Collapse of 14-story apartment（Photo 2-2 reference：https://www.jiji.com/jc/article?k=2023020800195&g=int）

24

２-２．Kahramanmaras Province
The intensity of the ground motions recorded and the seismic damage observed in the
Kahramanmaras province, which is situated closest to the epicenter, are described. The
observation stations for ground motions in Kahramanmaras are presented in Fig. 2-6.
There are a total of 5 observation stations, although data from two of them were notaccurately recorded. The ground motions recorded at stations TK4617 and TK4620,
which are in closest proximity to the locations we visited, are utilized. The time-historyof ground motion accelerations at TK4617 is presented in Fig. 2-7. The maximum groundmotion acceleration reaches 112.7 gal in the east-west direction, 145.6 gal in the northsouth direction, and 111.8 gal in the up-down direction. The instrumental seismic
intensity at TK4617 is 4.7. The acceleration, velocity, and displacement response spectra
for TK4617 are presented in Fig. 2-8, while the demand response spectrum is presented
in Fig. 2-9. Conversely, the time-history of ground motion accelerations at TK4620 ispresented in Fig. 2-10. The maximum ground motion acceleration reaches 316.6 gal in
the east-west direction, 298.2 gal in the north-south direction, and 176.6 gal in the updown direction. The instrumental seismic intensity at TK4620 is 5.0. The acceleration,
velocity, and displacement response spectra for TK4620 are presented in Fig. 2-11, while
the demand response spectrum is presented in Fig. 2-12. It is evident that the response
spectra for the recorded ground motions at TK4617 and TK4620 are generally smaller
than those of the JMA-Kobe ground motion across most of the natural period ranges.

Fig. 2-6 Observation stations in Kahramanmaras urban area

25

500

max： 112.7gal
0-500

east-west
0

20

40

60

80

100

120

Time (s)500

max： 145.6gal

0north-south
-500

0

20

40

60

80

100

120

Time (s)500

max： 111.8gal

0

-500

up-down
0

20

40

60

80

100

120

Time (s)Fig. 2-7 Time-history of ground motion acceleration（TK4617）

3

400

Acceleration

2.5

blue: JMA-kobe
red: TK4617

2
1.5

60

Velocity

Displacement

50

300
40
200

30

1

20
100

0.5
0

10
0

1

2

3

0

0

Natural Period T(s)

1

2

0

3

400

2

3

60

Velocity

Acceleration

1

Natural Period T(s)(a) Horizontal direction

3
2.5

0

Natural Period T(s)Displacement

50

300
2

40

1.5

200

blue: JMA-kobe
red: TK4617

1

30
20

100

0.5

10
0

1

2

3

Natural Period T(s)

0

0

1

2

0

3

0

Natural Period T(s)1Fig. 2-8 Acceleration, velocity, displacement response spectra（TK4617）

Teﬀ=0.5s

Teff=1.0s

1.5s
2.0s
2.5s
3.0s

Fig. 2-9 Demand response spectrum（TK4617）

26

2Natural Period T(s)(b) Vertical direction

Sa(g)

0

3

500

max： 316.6gal
0-500

east-west
0

20

40

60

80

100

120

Time (s)500

max： 298.2gal

0

-500

north-south
0

20

40

60

80

100

120

Time (s)500

max： 176.6gal

0

-500

up-down
0

20

40

60

80

100

120

Time (s)blue: JMA-kobe
red: TK4620

2
1.5
1
0.5
0

0

1

2

3

Natural Period T(s)3

Acceleration

2.5
2
1.5

blue: JMA-kobe
red: TK4620

1
0.5
0

0

1

2

3

400

Velocity

300
200
100
0

0

1

2

3

Natural Period T(s)(a) Horizontal direction

400

Velocity
300
200
100
0

0

1

Natural Period T(s)23Natural Period T(s)Horizontal Displacement Response (cm)Acceleration

Vertical Displacement Response (cm)Horizontal Velocity Response (cm/s)

3
2.5

Vertical Velocity Response (cm/s)

Vertical Acceleration Response (g)Horizontal Acceleration Response (g)Fig. 2-10 Time-history of ground motion acceleration（TK4620）

60

Displacement

50
40
30
20
10
0

0

1

Displacement

50
40
30
20
10
0

0

1

3
Teff=0.5s2
Teff=1.0s

1.5
1.5s
2.0s

0.5
0

2.5s
3.0s

0

10

20

30

40

50

60

Sd(cm)
Fig. 2-12 Demand response spectrum（TK4620）

27

2Natural Period T(s)Fig. 2-11 Acceleration, velocity, displacement response spectra（TK4620）

1

3

60

(b) Vertical direction

2.5

2Natural Period T(s)3The seismic damages resulting from the earthquakes at the six locations (① to ⑥)
visited during the survey in the urban area of Kahramanmaras are presented in Photo 23 to 2-8.

These six locations are illustrated in Fig. 2-6. The damage conditions at

locations ① and ② are described. Location ① is where the Onikisubat municipal
office is situated. Location ② is in close proximity to the observation station TK4617
and is believed to have experienced ground motions with an instrumental seismic
intensity of approximately 4.7. As shown in Photo 2-3 on the left, the four-story RC
building of the Onikisubat municipal office does not exhibit any structural damage.
However, as shown in Photo 2-3 on the right, a portion of the dry external wall has
collapsed. At the location ②, near the Onikisubat municipal office, as seen in Photo 2-4
in the left, recently constructed high-rise apartment buildings stand side by side.
Concrete walls without reinforcements have fallen in an out-of-plane direction.
Additionally, as shown in Photo 2-4 on the right, exterior walls have collapsed towards
the entrance. If individuals had been present at the time of the collapse, severe humancasualties would have occurred. Generally, at Locations ① and ②, while structuralmembers may have experienced damages, non-structural members, such as exterior walldamage, are more prominent.

Photo 2-3 Seismic damage in Kahramanmaras (Location ①)

Photo 2-4 Seismic damage in Kahramanmaras (Location ②)28

It is postulated that Locations ③ and ④ experienced ground motions with an
instrumental seismic intensity of approximately 5.0, given their proximity to observation
station TK4620. At Location ③ , three ten-story residential complexes underwent
structural collapse, and as shown in Photo 2-5 on the left, debris had been cleared,leaving cleared construction sites. There was scarce evidence available to ascertain thecauses and types of the building collapses. Nevertheless, steel reinforcements ofconsiderable diameter were discovered protruding from the ground as shown in Photo 25 on the right, which were presumed to be main reinforcements at the lower levels. Bothdeformed and round steel reinforcements were identified. The influences of round steel
reinforcements as a contributing factor to the building collapse cannot be definitelydetermined. However, the AIJ standard for the structural calculation of reinforced
concrete structures specifies that primary reinforcements should be deformed
reinforcements exceeding a diameter of D13, as stated in Article 13, and that more thanfour primary reinforcements should be deformed reinforcements with a diameter greaterthan D13, as outlined in Article 14. A few buildings suffered complete collapses, while
concurrently, as shown in the background of Photo 2-5 on the left, numerous medium
and high-rise structures appear to have withstood the event without any discernible
structural damage, based on their external appearance. At Location ④, as shown in
Photo 2-6 on the left, the upper portion of a minaret belonging to the Yunus Cami Mosquecollapsed, and as shown in Photo 2-6 on the right, stacked stones plummeted to theground or onto the mosqueʼs roof. It is worth noting that Location ④ is nearly
indistinguishable from the ground motion observation station TK4620.

Photo 2-5 Seismic damage in Kahramanmaras (Location ③)

29

Photo 2-6 Seismic damage in Kahramanmaras (Location ④)

Locations ⑤ and ⑥ experienced exceptionally severe seismic damage within theurban area of Kahramanmaras, as shown in Photo 2-7 on the left, presenting a profoundly
devastating state throughout the district. These locations, in close proximity toobservation station TK4620, exhibited significantly more extensive seismic damage
compared to the district encompassing Locations ③ and ④. While it is postulated that
this disparity could be attributed to unfavorable soil conditions leading to seismic
amplification and the dense arrangement of commercial and residential buildings,
quantitatively verifying these factors may prove challenging. At Location ⑤, as shown in
Photo 2-7 on the right, a column with substantial spacing between hoops, which serveas shear reinforcements, was observed. Although the hoops should have been more
densely arranged around the beam-column joint, they were spaced widely, resembling
the configuration seen in the central section of a beam.
At Location ⑥, as shown in Photo 2-8, a bustling downtown area characterized by adense congregation of commercial and residential structures along major throughfares
suffered extensive building collapses. In many buildings, the ground floor consists ofshops, while the stories above the second-floor house residential units. The shops on
the ground floor feature large openings, resulting in an eccentricity in the stiffness
distribution across the height of the structures. Moreover, the building layout itself
exhibits significant eccentricity due to the protrusion of balconies and the irregulararrangement of columns and walls. It is conjectured that such an imbalance in the overall
structural system contributed to the collapses, emphasizing the importance ofconsidering stiffness distributions across the height and the building plan, as well as thefundamental concept of seismic design, including the utilization of designated designroutes such as routes 2 and 3 employed in Japan.

30

Photo 2-7 Seismic damage in Kahramanmaras (Location ⑤)

Photo 2-8 Seismic damage in Kahramanmaras (Location ⑥)

２-３．Hatay Province
The ground motion intensities measured and seismic damage observed in the provinceof Hatay are described. Specifically, three urban areas in Hatay province, namely Antakya,
Samandag, and Iskenderun, were visited and surveyed. The locations of the observation
stations in Hatay province are illustrated in Fig. 2-13. The data recorded in Samandag isof poor quality. Similarly, a significant portion of the data recorded in Iskenderun is alsoof poor quality, with the exception of one station located far from the urban area.
Consequently, the ground motions recorded in the Antakya urban area are utilized. The
locations of the observation stations in the Antakya urban area are illustrated in Fig. 214. There are four observation stations in the Antakya urban area, and the groundmotions recorded at TK3123, which is in close proximity to the visited and surveyed
location, as well as TK3124, situated in the district exhibiting extensive damage visible
from aerial photographs, are considered.
The time-history of ground motion accelerations at TK3123 is presented in Fig. 2-15.
The maximum acceleration recorded is 585.8 gal in the east-west direction, 652.1 gal in31the north-south direction, and 842.6 gal in the up-down direction. The instrumental
seismic intensity of TK3123 is 6.3. The acceleration, velocity, and displacement response
spectra at TK3123 are presented in Fig. 2-16, while the demand response spectrum ispresented in Fig. 2-17. Conversely, the time-history of ground motion accelerations at
TK3124 is presented in Fig. 2-18. The maximum acceleration recorded is 624.3 gal in theeast-west direction, 571.4 gal in the north-south direction, and 572.7 gal in the up-down
direction. The instrumental seismic intensity at TK3124 is also 6.3. The acceleration,
velocity, and displacement response spectra at TK3124 are presented in Fig. 2-19, andthe demand response spectrum is presented in Fig. 2-20. It is noted that the response
spectra of both recorded ground motions, TK3123 and TK3124, in Antakya exhibit acomparable level to that of the JMA-Kobe ground motions. The trends of the response
spectra for TK3123 and TK3124 are similar, and in the horizontal direction, both TK3123
and TK3124 exhibit greater velocity and acceleration spectra compared to the JMA-Kobeground motions for natural periods exceeding 1.0 sec. In the vertical direction, within therange of shorter frequencies, both TK3123 and TK3124 exhibit higher acceleration
responses than the JMA-Kobe ground motions.

Fig. 2-13 Observation stations in Hatay province

Fig. 2-14 Observation stations in Antakya urban area

32

1000

max： 585.8gal

500
0east-west

-500
-1000

0

20

40

60

80

100

120

140

Time (s)1000

max： 652.1gal

5000north-south

-500
-1000

0

20

40

60

80

100

120

140

Time (s)1000

max： 842.6gal

500
0up-down

-500
-1000

0

20

40

60

80

100

120

140

Time (s)Acceleration

blue: JMA-kobe
red: TK3123(a) Horizontal direction
Velocity

Horizontal Displacement Response (cm)

Velocity

Vertical Displacement Response (cm)Horizontal Velocity Response (cm/s)

Acceleration
blue: JMA-kobe
red: TK3123

Vertical Velocity Response (cm/s)

Vertical Acceleration Response (g)Horizontal Acceleration Response (g)Fig. 2-15 Time-history of ground motion acceleration (TK3123)

Displacement

Displacement(b) Vertical direction
Fig. 2-16 Acceleration, velocity, displacement response spectra (TK3123)

3
Teff=0.5s

Teff=1.0s

2.5

1.5s

2
1.5

2.0s

1

2.5s

0.5

3.0s

0

0

50

100

150

Sd(cm)
Fig. 2-17 Demand response spectra (TK3123)

33

1000

max： 624.3gal

500
0east-west

-500
-1000

0

20

40

60

80

100

120

140

Time (s)1000

max： 571.4gal

5000north-south

-500
-1000

0

20

40

60

80

100

120

140

Time (s)1000

max： 572.7gal

500
0up-down

-500
-1000

0

20

40

60

80

100

120

140

Time (s)Acceleration

blue: JMA-kobe
red: TK3124(a) Horizontal direction
Velocity

Horizontal Displacement Response (cm)

Velocity

Displacement

Vertical Displacement Response (cm)Horizontal Velocity Response (cm/s)

Acceleration
blue: JMA-kobe
red: TK3124

Vertical Velocity Response (cm/s)

Vertical Acceleration Response (g)Horizontal Acceleration Response (g)Fig. 2-18 Time-history of ground motion acceleration (TK3124)

Displacement(b) Vertical direction
Fig. 2-19 Acceleration, velocity, displacement response spectra (TK3124)

3
Teﬀ=0.5s
Teff=1.0s

2.5

1.5s

2
1.5

2.0s
2.5s

1

3.0s

0.5
0

0

50

100

150

Sd(cm)
Fig. 2-20 Demand response spectra (TK3124)

34

Photos 2-9 and 2-10 illustrate the seismic damage observed in the new and old urban
areas of Antakya, respectively. The locations visited and surveyed in both the new andold urban areas of Antakya are indicated in Fig. 2-14. In the new urban area of Antakya,
as shown in the left image of Photo 2-9, numerous medium- and high-rise reinforced
concrete (RC) building structures suffered collapses, with debris having been cleared
from the sites. In the right image of Photo 2-9, even among the standing buildings that
did not collapse, the exterior brick walls experienced significant out-of-plane
displacement, resulting in substantial damage and a ruinous appearance. The specificstructural distinctions between the collapsed and non-collapsed buildings are not clearly
evident. Notably, the left image of Photo 2-9 reveals that the non-collapsed buildings
exhibit a predominantly regular configuration, with beam and column moment-resisting
frames being prominently featured. Moving forward, it is imperative to elucidate themechanisms and factors contributing to the collapses of the affected buildings.
Conversely, in the old urban area of Antakya, as shown in Photo 2-10, numerous
masonry structures constructed with stones and bricks suffered collapses. Additionally,some wooden structures also experienced failures. Debris still remains at the sites. It isnoteworthy that the stacked stones and bricks slipped due to the seismic forces andfurthermore, slipped due to the overturning moments, known as P-Delta effects, leading
to loss of stability and cascading collapse. Considering this, the structural integrity
throughout the height of masonry structures is of paramount importance.

Photo 2-9 Seismic damage in Antakya new urban area

Photo 2-10 Seismic damage in Antakya old urban area

35

The seismic damage observed in Samandag is shown in Photo 2-11. Within theresidential district of Samandag, a three-story apartment building experienced a collapse
with the story mechanism. While the second and third stories sustained minimum
damage, as evident from the spacing between adjacent buildings, the first story exhibiteda significant inclination. This phenomenon can be attributed to the distinctive weak-story
collapse mechanism, wherein the drift is concentrated in the first story. This is clearly
the weak-story collapse mechanism with the drift concentration in the 1st story. As shownin the right image of Photo 2-11, plastic hinges formed at the top and bottom of thecolumns within the first story, leading to the occurrence of the story collapse mechanism.
Conversely, the beams and floors remained largely undamaged. It is imperative toconsider global collapse mechanisms that prioritize beam yielding before column yielding,accounting for the relative strengths of the columns and beams, or employ multi-story
seismic walls to mitigate the occurrence of the story collapse mechanism.

Photo 2-11 Seismic damage in Samandag

In the urban area of Iskenderun, as shown in the left image of Photo 2-12, tallapartment buildings collapsed in their entirety. Numerous cracks marred the walls ofthese high-rise structures, resulting in significant damage, and it appeared that the entire
structures exhibited a slight inclination. These sites are situated along the coastline, and
it is evident that liquefaction played a role in these occurrences. Among them, three
medium- and high-rise apartment buildings experienced a pancake-style collapse. As
shown in the right image of Photo 2-12, the debris had already been cleared, leaving
cleared construction sites. The pancake collapse entails a progressive sequence offailures, wherein certain structural members succumb to the earthquake-induced
shaking, subsequently causing a chain reaction that leads to the failure of other members,
resulting in an overall loss of structural stability. One common characteristic among thesecollapses is the absence of redundancy. It is highly desirable to incorporate redundant
design principles, wherein additional members that remain intact during seismic events36

are implemented or other members possess the capacity to bear the load, even if one
member fails.

Photo 2-12 Seismic damage in Iskenderun

２-４．Collapse Mechanism and Prevention
In the design guidelines for earthquake-resistant reinforced concrete buildings basedon inelastic displacement concept by the AIJ (Architectural Institute of Japan), as shownin Fig. 2-21, the column yielding mechanism, wherein the top and bottom of columns
yield prior to the yielding at beam ends, is deemed perilous. Conversely, the beam yielding
mechanism, where beams yield at the ends, is recommended. This recommendation isbased on the understanding that the column yielding mechanism may give rise to thestory mechanism, while the beam yielding mechanism facilitates a global yielding
mechanism. The building structure presented in Photo 2-11, depicting seismic damage
in Samandag, exhibits the column yielding mechanism. To mitigate the occurrence of thestory collapse mechanism, the addition of multi-story seismic wall frames isrecommended. These seismic wall frames help ensure a more uniform distribution ofstory drift angles across the structural height during earthquake motion, thus reducing
the concentration of drift in specific stories and effectively preventing the story collapse
mechanism.

Fig. 2-21 Collapse mechanism and prevention

37

In future endeavors pertaining to seismic strengthening and retrofitting in Turkey,
diverse methodologies will be taken into account. As shown in Fig. 2-22, potential options
encompass seismic control approaches involving continuous columns and walls, such as
rocking multi-story seismic walls, as well as seismic isolation methods that concentrate
deformations within a seismic isolation story.

Fig. 2-22 Seismic control with continuous members and seismic isolation

38

３．SURVEY REPORT II

Specific Building Forms and Damage Conditions : From a

Perspective of Structural Design
３-１．Introduction
Even in modern architecture, its construction techniques are rooted in history, climate,culture, and customs. While it cannot be said that Japan's seismic technology has
universal applicability internationally, this allows for a different perspective when
examining the situation of earthquakes compared to seismic technology in Turkey.
３-２．The Impact of Adjacent Building Spacing on the Expansion of Seismic Damage
The seismic forces occurring in individual buildings are designed under the assumptionthat each building bears its own load. However, in urban areas of Turkey, where building
walls are located on property boundaries and adjacent buildings are closely attached, it
is believed that a cluster of buildings within a city block behaved as a unified entity inresponse to seismic horizontal motion. On the other hand, the construction periods ofindividual buildings vary, and it is speculated that there were buildings with insufficientseismic resistance considering the current seismic standards. Therefore, it is presumed
that the seismic horizontal forces of the interconnected cluster of buildings led toconcentrated destruction in certain buildings, and further, the horizontal forces
concentrated on the next building, resulting in a chain reaction of destruction and the
expansion of damage.

Photo 3-1 Adjacent buildings in close contact

By the way, in Japan, the setback of building walls from property boundaries isregulated by the Civil Code (established prior to the Building Standards Law). As a result,even if adjacent buildings experience horizontal displacement during an earthquake, it isensured that they do not collide with each other.
３-３．The Commercial Use of Lower Levels in Mid-Rise and High-Rise Buildings
and its Relationship to Seismic Damage
39

Photo 3-2 Buildings with Commercially Used Lower Levels and Mezzanine Floors

In the case of high-rise and mid-rise buildings in urban
areas of Turkey. The lower levels are predominantly used
for commercial purposes. As a result, the lower levels
often lack walls and some have mezzanine floors withhigh ceilings. Furthermore, to create open storefronts
facing the streets, the column width in the direction of
the storefront is narrow. Consequently, the lower levels
exhibit lower stiffness in the direction facing the street,

Photo 3-3 Column Flattened in theStorefront Direction

leading to a structural configuration (commonly known aspiloti system) where seismic energy tends to concentrate in the lower levels, resulting indamage. Additionally, the column width is wide in the depth direction but narrow in thestorefront direction (same as the beam width), which makes the structure prone tocolumn bending yielding and collapse in the storefront direction. It is presumed thatdamage occurred due to this type of rigid-jointed structure. It is worth noting that thecurrent Turkish seismic design code, TBEC-2018, includes considerations for nonuniform horizontal stiffness and mezzanine floors.
３-４．The Unreinforced Masonry Infill Walls in RC Buildings and Seismic Damage
Based on the observation of the remaining buildings, collapsed buildings' debris, orbuildings under construction in urban areas of Turkey following the earthquake, it can beseen that the high-rise reinforced concrete (RC) buildings have RC rigid-jointed
structures, with external and internal walls made of unreinforced insulated concrete
blocks or brick masonry. Consequently, these buildings were unable to follow the interstory displacement of the RC rigid-jointed structures during the earthquake. They
collapsed or suffered partial collapses and dislodgment prior to the structural collapse,
leading to an increased risk of casualties.

40

Photo 3-4 The Damaged RC Buildings (Left) and Under-Construction RC Buildings (Center/Right)

By the way, in Japan, the Building Regulations for Urban Areas were revised in the year
following the occurrence of the Great Kanto Earthquake (1924). The revised regulations
stipulated that masonry infill walls should be reinforced with steel and connected to thestructural frame. As a result of this provision, the infill walls were integrated into thereinforced concrete (RC) structure as rigid-jointed elements, leading to the development
and widespread adoption of Japan's unique RC construction method known as "seismic
wall-attached rigid-jointed structure." In Japan's capacity design and allowable stressdesign methods, masonry infill walls are considered not to significantly affect the seismic
performance of the structural frame. However, the inherent period of the building is
calculated using an approximation formula that provides a conservative evaluation(shorter period than the actual) for safety assessment. It is worth noting that the current
Turkish seismic design code, TBEC-2018, also incorporates considerations for the
influence of infill walls on horizontal stiffness.
３-５．The Qualification System for Structural Designers in Turkey and Current
Seismic Design Codes
In Turkey, holders of a Bachelor's degree in Civil Engineering (4-year program) are
eligible to perform the structural design of buildings, regardless of their scale. There isno licensing system or renewal system for architectural structural designers, andpractical experience is not required. Furthermore, there is no system in place to ensure
the maintenance and improvement of technical skills.
On the other hand, the current seismic code in Turkey, TBEC-2018, which was revisedin 2018, complies with Eurocode-8 and is generally equivalent to Japan's new seismic
standards (either horizontal-load-carrying-capacity or response-limit-capacity based
design). As a result, seismic regulations and seismic design have become more advanced,
and structural calculations are performed using structural analysis software. However, it
is not easy to verify the adequacy of the structural calculation report generated by thesoftware, including the suitability of the structural analysis program, the validity ofstructural modeling, and the consistency with the design drawings.
41

There is a possibility that deficiencies in the experience, technical skills, or
professional ethics of structural designers, as well as the inadequate capabilities ofstructural design reviewers, may lead to flaws in the structural design.
In Japan, to engage in architectural structural design, it is required to obtain a national
qualification established by the Architect Act, and there are penalty provisions for
misconduct by qualified individuals. Specifically, one must graduate from thearchitectural department of a university, have more than 2 years of design work
experience, and pass the national examination for first-class architects. To perform thestructural design of large-scale buildings, an additional 5 years of structural design work
experience is required, followed by completion of a certified course designated by thegovernment and obtaining the national qualification of first-class architectural structuraldesigner. Additionally, first-class architectural structural designers are required to attend
regular courses for first-class architects and regular courses for structural design firstclass architects every 3 years.
３-６．Others
The current seismic code in Turkey, TBEC-2018, the International Building Code (IBC2018) in the United States, and Japan's response-limit capacity-based design are thelatest seismic standards that may ultimately lead to the adoption of ductile and flexible
structures in building construction. However, Japan's seismic standards for reinforced
concrete (RC) low-rise and mid-rise buildings have historically favored strong and rigid
structures since their establishment in 1924, leading to the widespread use of Japan's
unique seismic wall-bearing rigid frame structures. As a result, the columns in Japanese
RC buildings are noticeably thicker compared to those in Europe and the United States,
and the cross-sectional area (wall volume) of vertical members such as columns, seismic
walls, and wing walls in RC structures is also larger. Increasing the wall volume not only
enhances the horizontal resistance of the structure but also increases its vertical support
capacity. This has been demonstrated by earthquake damage surveys, showing thatbuildings with larger wall volumes tend to experience smaller seismic damage.

42

４．SURVEY REPORT Ⅲ Visits to Mayors of the Affected Municipalities and Toursof Tents and Container Temporary Housing, etc.
４-１．Results of Hearing with Mayors of the Affected Municipalities
Hearings were held with visits to the Mayor of Çukurova, Adana and the Mayor of
Onikişubat, Kahramanmaraş on April 14 (Fri.), the Hatay Metropolitan Municipality Mayoron April 15 (Sat.) and the Mayor of Payas, Hatay on April 16 (Sun.). Below are the maincomments obtained.
・As the mayor, I have decided to demolish many of the damaged buildings in the future.
・In some of the collapsed buildings, the owners had removed the columns without permission.
・We would like you to share with us your experiences of recovery and reconstruction after the earthquake in Japan.
We would like to consider sending our engineers to Japan.
・We have newly decided to prohibit high-rise buildings and limit them to 5 stories or less in principle as a postearthquake urban development standard, and to set the following building standards: (1) stop using mezzanine
floors, (2) provide basement floors, and (3) strengthen ground inspections and provide guidance on ground
improvement.
・Instead of simply rebuilding the damaged buildings, we will carefully consider a reconstruction plan for community
development.
・Food and other daily commodities are sufficient. There is a lack of temporary housing for disaster victims andaccommodations for recovery workers.
・Infrastructure such as water, electricity, and gas is fine. It was restored about a week after the earthquake.
・Earthquake forecasts had been made even before the earthquake, but countermeasures were not taken in time.
・We are thinking with universities and experts about new town planning for the future.
・Our thoughts are as follows (1) To know the reality of the earthquake. And to remember that reality. (2) Make
concrete plans based on the reality of the disaster. (3) Social education about the disaster is necessary, andsupport from various fields is needed. (4) Steadily implement the recovery plan, including the necessary financial
planning.
・We would very much like to learn about Japan's experience in earthquake recovery. Furthermore, we would like to
ask for your support, including financial support.
・In our district, there were few buildings that collapsed, but there are more than 1,000 damaged buildings.
・Checks on the damaged buildings were completed within a week.
・Our district had begun removing dangerous buildings with low earthquake resistance before the earthquake. Threeof these buildings could not be removed due to a court case, but they collapsed in the earthquake, killing morethan 400 people. The residents who were able to remove the buildings and relocate were grateful. I was reminded
once again of the importance of preparation before an earthquake strikes.
・Japan has a strong image of always developing while experiencing disasters.
・I had visited the city of Kobe in 2000 following the 1999 Turkish earthquake. The people of Kobe City explained tome the situation of the city and the rescue efforts.

From the above comments, the following points, among others, are the maincommonalities(1) We want to create a disaster-resistant community, not simply rebuild buildings.
(2) In order to achieve this, we would like to ask for Japan's support in a variety of ways,
including sharing of knowledge and experience in earthquake recovery, quakeresistant technology, and funds.
43

４-２．Tours of Tents and Container Temporary Housing, etc.
On April 14 (Fri.), we visited the disaster relief center provided by Istanbul Beyoğlu in
Kahramanmaraş Dulkadiroğlu; on April 16 (Sun.), we visited a tent village in Hatayİskenderun, two container temporary housing sites in Hatay Payas, and a field hospitalprovided by Qatar in Hatay Payas.
４-２-１．Beyoğlu Disaster Relief Center in Kahramanmaraş Dulkadiroğlu

Photo 4-1 Converting a soccer field into the disaster relief center.

Photo 4-3 Providing shoes.

Photo 4-2 Providing clothing.

Photo 4-4 Serving meals for 15,000 people daily.

４-２-２．Tent Village in İskenderun Provided by the National Government,
Municipalities, and Turkish Red Crescent, etc.

Photo 4-5 Entrance to the tent village. It can accommodate

Photo 4-6 Meals provided by Turkish Red Crescent.

up to 2700 people. At the time of our visit, 2050 people were living in
450 tents. They were gradually moving into container temporary housing nearby.

44

Photo 4-7 Ramadan meal tent

Photo 4-8 Same as on the left.

provided by Üsküdar district, İstanbul.

Serving meals for 4,000 people.

Photo 4-9 Tent for children's mental health care.

Photo 4-10 Mobile libraries (tent and bus).

Photo 4-11 Residential tent. Heat was becoming a problem. Photo 4-12 School by military tents.

４-２-３．Container Temporary Housing, etc. in Payas

Photo 4-13 335 container temporary housing units

Photo 4-14 There was also a soccer field and a gymnasium.

to be completed next week. There were laundry
containers, hospital containers, school containers, etc.

Photo shows the soccer field.

45

Photo 4-15 Container appearance.

Photo 4-16 Inside the container. 21 ㎡
A kitchen was attached.

Photo 4-17 Inside the container.

Photo 4-18 Container temporary housing currently in use

Toilet, shower and hand wash.

Photo 4-19 Field hospital provided by Qatar.

was also visited.

Photo 4-20 Inside the field hospital provided by Qatar.

46

５．SURVEY REPORT Ⅳ Status of Damage to Historic Buildings
Since we had special access to the courtyard of Ulu Camii (15C) in the Dulkadiroğlu
district of Kahramanmaraş, in 5-1 we present photographs of the damage to Ulu Camii
taken there. In 5-2, photos of damage to other major historic buildings are posted.
５-１．Kahramanmaraş Ulu Camii

Photo 5-1 The minaret collapsed and stones were

Photo 5-2 The entrance area was damaged.

lying on the ground. The entrance area was damaged.

Photo 5-3 Damaged portico.

Photo 5-4 Damaged portico.

Photo 5-5 Arch section of portico

Photo5-6 Arch section of portico47

Photo 5-7 The minaret was cracked.

Photo 5-8 Stone mortise in collapsed minaret.

Photo 5-9 Steel tie connecting the stones of the collapsed
minaret.

Photo 5-10 Shot by drone.

Photo 5-11 Shot by drone.

48

Photo 5-12 The building was damaged by the minaret collapsing and falling stones.

Photo 5-13 Staircase inside the minaret.

Photo 5-14 The surrounding corridor was safe.

Photo 5-15 Cracks in exterior wall.

Photo 5-16 Cracks in exterior wall.

49

５-２．Other Major Historical Buildings

Photo 5-17 Antakya, Hatay. Ulu Cami.
The famous minaret was erected near the tree in front, but it was completely destroyed along with the building.

Photo 5-18 Antakya, Hatay. Former Parliament building.

Photo 5-19 Antakya, Hatay. Greek Orthodox Church.

Hatay Devleti döneminde meclis binası.

Photo 5-20 Antakya, Hatay.

Photo 5-21 Antakya, Hatay. Sarımiye Camii.

Protestant Church.

The minaret collapsed.

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Photo 5-22 Antakya, Hatay. Habib-i Neccar Camii
The minaret and dome collapsed.

Photo 5-23 Antakya, Hatay. Mahremiye Camii.

Photo 5-24 İskenderun, Hatay.

The minaret collapsed.

Greek Orthodox Church.

Photo 5-25 Payas, Hatay. Sokullu Mehmet Paşa Külliyesi designed by Mimar Sinan.
The minaret collapsed.

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６．Recommendations Based on the Survey Reports
Based on the above survey reports, we make the following eight recommendations inthis report.
Ⅰ. Verification of the Validity of the Current Seismic Code TBEC-2018
It is necessary to verify whether buildings designed according to TBEC-2018
experienced any seismic damage or issues, even for buildings under construction where
significant damage may not have occurred but where unreinforced masonry infill walls
and partition walls may have been damaged or fallen.
Furthermore, the strong ground motion records of this earthquake were recorded atobservation stations of the Turkish National Strong Motion Network, but the records fromseveral stations were incomplete. While AFDA is currently investigating the cause, it isnecessary to conduct a comprehensive inspection of all observation stations.
Ⅱ. Seismic Performance of Non-Structural Elements (Cladding, Ceilings, Building
Facilities, etc.)
Non-structural elements should remain undamaged during moderate earthquakes (atthe damage limit) and should not collapse, detach, or fall during major earthquakes (atthe safety limit). It is also important to prevent the toppling of furniture and fixtures.
Ⅲ. Reinforcement of Masonry Filling Walls in RC Buildings
Reinforcement with steel bars or other means is necessary to prevent the collapse ordetachment of masonry filling walls during earthquakes. Additionally, the conversion of
RC filling walls into seismic walls or load-bearing walls is desirable. RC filling walls not
only enhance the horizontal resistance of the building but also increase its verticalsupport capacity, reducing the risk of collapse.
Ⅳ. Lightweighting of Non-Structural Elements
Masonry filling walls, even with reinforcement, have limited seismic performance andcan be unclear in structural analysis. On the other hand, masonry filling walls are heavy
and increase the seismic forces acting on the structure. Therefore, lightweight
alternatives such as drywall partitions should be used for interior walls. Lightweightmaterials like ALC panels are also desirable for non-structural exterior walls. The moststraightforward approach to improving seismic performance is to lighten the building's
weight.

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Ⅴ. Ensuring Reliable Isolation or Integration with Adjacent Buildings
When buildings are in close proximity, there is a higher risk of chain collapse, wherebuildings with different vibration characteristics or seismic resistance interact andcollapse together. Therefore, it is necessary to provide spacing between adjacentbuildings to prevent collision in the event of horizontal displacement caused by seismic
forces. However, achieving this while maintaining the plot ratio can be challenging. One
potential solution is the integration of adjacent buildings, although this raises issues
related to land ownership and usage rights. By integrating buildings, two adjacentcolumns that would be in close proximity can be merged into a single larger column, andtwo adjacent infill walls can be combined into a single seismic wall, resulting in a highly
seismic-resistant structure. Additionally, shared facilities such as stairs and elevators
can be rationalized and used.
Ⅵ. Development of Seismic Strengthening Methods for Masonry Minarets
In all of the traditional mosques that we were able to inspect, the minarets hadcollapsed. In addition, in the Kahramanmaraş Ulu Camii, it was confirmed that thebuilding was damaged due to collapsed minarets. The development of seismic
reinforcement methods for masonry structures is urgently needed to protect cultural
heritage buildings, and among them, the promotion of seismic reinforcement of minarets
is expected to have a very immediate effect in protecting cultural heritage buildings.
Methods such as the Hoop-Iron construction (developed by foreign architects hired inJapan in the late 19th century) for seismic reinforcement of brick structures (M. Horiuchi:"A Study on The Hoop-Iron Construction Adopted in The Old Building of The Ministry ofJustice," J. Archit Plann. Environ. Eng., AIJ, No.499, pp. 193-198, Sep., 1997) or the stoneand steel prefabrication method proposed and adopted by Arup Group Limited for theconstruction of the spires of the Sagrada Família church can provide inspiration.
(https://www.arup.com/projects/sagrada-familia)

Fig. 6-1 Reinforcement Method for Brick Chimneys by R. Seel （M.Horiuchi, 1997）

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Fig. 6-2

Illustration of J. Lescasse's Brick Construction Method（M.Horiuchi, 1997）

Ⅶ. Establishment of an international mechanism to share experiences of disasteraffected municipalities
From the interview with the mayors of the affected municipalities, several of themcommented that they would like to share information with Japan, which is also anearthquake-prone country like Turkey. An international mechanism to share the various
efforts and experiences of affected municipalities in Japan, Turkey, and other countries
is required to be established.
Ⅷ. Fostering and raising public awareness about the earthquake disasterIn the wake of the recent earthquake in Turkey, it is necessary for the entire population,
not just the government and experts, to once again recognize and act on the need toprepare in advance to protect the lives and property of the people against earthquakes.
Education and awareness-raising about housing for all ages is of utmost importance forthis purpose. For example, educational institutions such as Bahçeşehir University could
collaborate with the government and local authorities to promote educational programs.

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７．List of Media Coverage
７-１．Turkey
・https://twitter.com/sonercetin01/status/1646796971519221762?t=OErXPhdMo_66HoICPHtOwQ&s=19
・https://www.instagram.com/p/CrAqP9GIaiu/?igshid=MDJmNzVkMjY=・https://8gunhaber.com/Mobile.aspx?go=habergoster&hid=59544
・https://penceretv.com/belediyelerimiz/chpli-savas-hatayi-yapilandiracagiz-258549h・https://www.yenimanset.com.tr/haber/japon-kobe-belediyesi-hataya-birikimini-aktaracak-356.html
・https://www.havadishaber.net/japon-belediye-hataya-birikimini-aktaracak/・https://www.iha.com.tr/istanbul-haberleri/hirosima-magduru-japon-kiz-sadakonun-bin-turna-kusluorigami-dilegi-turk-depremzedelere-4287782/
・https://www.dha.com.tr/yerel-haberler/istanbul/merkez/hirosima-magduru-japon-kiz-sadakonun-binturna-2237584
・https://www.gercekgundem.com/guncel/hirosima-magduru-japon-kiz-sadakonun-bin-turna-kuslu-origamidilegi-turk-depremzedelere-419524
・https://www.bizimsamsun.net/hirosima-magduru-japon-kiz-sadakonun-bin-turna-kuslu-origami-dilegiturk-depremzedelere/
・https://www.gunestv.com/infinite-haber-devam-60254-haberi
・https://www.dha.com.tr/yerel-haberler/istanbul/merkez/hirosima-magduru-japon-kiz-sadakonun-binturna-2237584
・https://www.bursasondakika.com.tr/m/gundem/hirosima-magduru-japon-kiz-sadakonun-bin-turna-kusluorigami-dilegi-h153966.html
・https://haberton.com/hirosima-magduru-japon-kiz-sadakodan-turna-kuslu-dilek/
・https://www.batiantalya.com.tr/hirosima-magduru-japon-kiz-sadakonun-bin-turna-kuslu-origami-dilegiturk-depremzedelere
・https://www.memleket.com.tr/hirosima-magduru-japon-kiz-sadakonun-bin-turna-kuslu-origami-dilegi-turk2211881h.htm
・https://beyazgazete.com/haber/2023/4/18/hirosima-magduru-japon-kiz-sadako-nun-bin-turna-kusluorigami-dilegi-turk-depremzedelere-6777314.html
・https://www.medyaege.com.tr/sadakonun-origamisi-umut-olacak-217726h.htm
・https://www.bizimizmir.net/hirosima-magduru-sadako-nun-bin-turna-kuslu-origami-dilegi-turkdepremzedelere-54843
・https://www.ekoiq.com/japon-heyeti-deprem-bolgesinin-toparlanmasi-icin-isbirligi-sart/?amp=1
・https://www.dha.com.tr/gundem/hirosima-magduru-japon-kiz-sadakonun-bin-turna-kuslu-origami-dilegiturk-depremzedelere-2237588
・https://www.gayrimenkulhaber.com/guncel/prof-dr-murat-dundar-turkiyede-sadece-binalar-cokmemisyapi-denetim-sistemi-de-cokmustur/55

・https://youtu.be/DrDGsWkvUGY
・https://youtu.be/VRmDX67GNnc

７-２．Japan
・https://www3.nhk.or.jp/kansai-news/20230412/2000072752.html
・https://sun-tv.co.jp/suntvnews/news/2023/04/11/66142/
・https://www.youtube.com/watch?v=jtfl7IIKqJA・https://nordot.app/1018447022640136192
・https://mainichi.jp/articles/20230413/ddl/k28/040/245000c
・https://info.mukogawa-u.ac.jp/publicity/newsdetail?id=4348
・https://www3.nhk.or.jp/kansai-news/20230502/2000073391.html
・https://www3.nhk.or.jp/lnews/kobe/20230502/2020021764.html
・https://www.yomiuri.co.jp/world/20230503-OYT1T50088/
・https://www.tiktok.com/@ytvnews/video/7228156199231917314
・https://www.kobe-np.co.jp/news/kobe/202305/0016337257.shtml
・https://info.mukogawa-u.ac.jp/publicity/newsdetail?id=4365
・The Yomiuri Shimbun, Wednesday, April 12, 2023
・The Asahi Shimbun, Wednesday, April 12, 2023
・The Kobe Shimbun, Wednesday, April 12, 2023
・The Sankei Shimbun, Wednesday, April 12, 2023
・The Yomiuri Shimbun, Wednesday, May 3, 2023
・The Kobe Shimbun, Thursday, May 11, 2023

Acknowledgments
In Turkey, we received a lot of support and cooperation from Bahçeşehir University. We
would also like to thank many local governments for their cooperation in conducting thissurvey. We would like to express our gratitude and sincerely pray for the earliest possible
recovery and reconstruction of the affected areas.
The dispatch of the three Mukogawa Women's University faculty members to the sitewassupportedbythe

Hyogo Prefecture"Turkey

Earthquake

Recovery andReconstruction Support Project”. We would like to express our gratitude for their support.

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【Special Contribution】

Problems that increased the destruction
caused by the Kahramanmaraş‐centered earthquake
Prof.Dr. Murat Dündar
Dean of Faculty of Architecture & Design,
Bahçeşehir University

The earthquake occurred in the city of Kahramanmaraş in Turkey on February
6, 2023 and the subsequent earthquakes in the same region caused great
destruction that would affect a total of 11 cities in the region, and many people
lost their lives. As it is always said, it is not the earthquake itself that causes lossof life, but the instability of man‐made structures.
When we look at the buildings that were heavily damaged or destroyed in thelast earthquake, we can say that it is possible to make an assessment in 4
categories in general:
1. Old Buildings/ Historical buildings: Buildings over 25 years old, built
according to the zoning regulations valid before 1998,
2. New Buildings: Relatively new buildings built according to updated
zoning regulations after the 1999 earthquake (including the 2007 and2018 updates),
3. Illegally constructed buildings: Buildings that were built illegally without
being bound by any law, regulation or legislation, but were legalized
through zoning amnesties generally applied by the state in the pre‐election periods, and the project and production processes arecompletely disabled,
4. Buildings with unauthorized structural changes: Buildings withstructural interventions such as column, beam cutting, etc. that the users
perform in line with their needs without any technical support.
The first official Earthquake Regulation in Turkey was published in 1975 and has
been updated 3 times in 1998, 2007 and 2018 based on the experiences gainedin the following earthquakes.
The static calculation methods used in the construction sector in Turkey are
generally similar to those used in European Union countries and the United
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States. Eurocodes are widely used as a reference for static calculations in theconstruction sector in Turkey.
Some of the commonly used static calculation software programs in Turkey
include SAP2000, ETABS, Sta4CAD, AxisVM, Robot Structural Analysis, andProtaStructure. Each program has its unique features, advantages, anddisadvantages, so the choice of which program to use may vary depending on
the project's specifications and needs.
The journey of a construction process in Turkey from capital to building issummarized in the schematic description shared in Fig.1. The process starts
with the application of the investor/property owner to the relevant
municipality with a petition in order to learn about the construction rights of
the land they intend to build.
The relevant unit of the municipality is obliged to provide the investor with the
documents needed for the project in accordance with the provisions of the
Master Zoning Plan and Implementation Development Plan in effect regarding
the land. With the submission of the relevant documents to the project team,the project phase, which includes architects and engineers, begins.
After obtaining the preliminary consent from the municipality, in which thestudies on the architectural project and the rights to build are confirmed, thearchitectural application project, ground survey, static, mechanical, electrical,
etc. all other projects are completed with the coordinated work of the relevant
professionals, and all projects are first approved by the Building Inspection
Firm; and then the process continues by submitting it to the municipality's
license unit for construction phase approval. The projects for which the license
has been obtained are delivered to the contractor company, which will
undertake the construction, as a package, and the construction process isstarted. At this stage, the construction process is taken under control by 3
different mechanisms: The first audit is the self‐audit carried out by aprofessional assigned by the construction company; It is the inspection carriedout at the construction site by the officials of the Building Inspection Firm,
which was assigned as the second inspection center; the last one is theinspections for control purposes carried out at the construction site at regularinspection visits by the relevant department of the Municipality.
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Figure 1: Construction permit phases and inspection mechanism officially implemented in Turkey

59When the construction process is over, firstly, after the Building Inspection
Firm gives its approval that the construction is completed, the construction
control unit of the municipality makes the final visit to confirm that theconstruction has been carried out in accordance with the project, and theprocess is completed by giving the occupancy (building occupancy permit) tothe property owner.
As it can be understood when the whole process is examined, the entire
process is repeatedly audited in the system itself, which is currently in effect,
and it can be continued by obtaining conformity approvals.
Within the scope of the observations and examinations made in theearthquake region, the main causes of structural damage in urban areas are
similar to the earthquake damage experienced in the past which can besummarized as follows: In attached buildings, the floor and beam alignments are at different
levels compared to the adjacent building, and the destructions due tothe hammering effect that occurs during the earthquake.
 Possible negligence in the inspection of productions following the start ofthe construction process, (Inadequacy of technical staff and lack ofsupervision in the fields of professional expertise,) Damages caused by interventions made during the usage process, Zoning plans and plan amendments made without considering disaster
data, and opening of agricultural lands and soils with low carrying
capacity for construction,
There is no doubt that the problems experienced especially in new buildings
would have been significantly reduced if the rules that have already been set inboth the legal legislation and the project design and permitting processes were
properly implemented and inspected.
As a justification for this view, we can show that a small number of buildingsthat implement these processes correctly are still standing. Although they are
few in number when we compare them in areas where destruction is intense, it
is seen that there are old and new buildings that did not receive any visible orless damage in this severe earthquake.
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The most basic problem in the processes is not the laws, regulations or the
projects created in accordance with them, but the lack of awareness of
responsibility in the people who will implement them. In summary, the main
factor in the growth of the disaster is that the awareness of the disaster spreadthroughout the society was not embraced as much as it should be by all the
stakeholders of the process.
In this context, all institutions and organizations, especially universities, shouldmake an intense and programmed effort in order to spread an approach inwhich the concept of creating disaster‐resilient cities is handled sensitively,internalized and become a collective consciousness, in a way that covers thewhole society.

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