|
|
| |
|
|
|
Prepared by
Key Findings and Lessons Learned
On June 22, 2002 at 7:28 a.m. local time, a MW 6.4 earthquake hit the northwestern region of Iran causing significant damage and casualties to small mountainous towns and villages in the area. According to the International Institute of Earthquake Engineering and Seismology (IIEES), the earthquake - named the Changureh (Avaj) earthquake - was felt as far as Tehran, which approximately 180 miles east of the epicenter. The latest reports indicate that the death toll is 261 and the number of injured exceeds 1,300 people. In addition, over 25,000 people are estimated to be homeless as a result of this earthquake. Figure 1 shows a map of the region with the epicenter and major faults located.
Figure 1 Fault Map of Northwestern Iran (Source: IIEES, 2002)Figure 2 shows a seismicity map of the region. Iran is populated with numerous NW-SE trending fault lines. This particular earthquake occurred on a hidden fault according to IIEES (2002).
Figure 2 Seismicity Map of Northwestern Iran (Source: IIEES, 2002)This preliminary report was prepared for the Multidisciplinary Center for Earthquake Engineering Research (MCEER) by Dr. Babak Mansouri of ImageCat, Inc. Dr. Mansouri was in Iran at the time of the earthquake. The photos that are contained in this report were taken during the first week after the earthquake. To document the effects from this moderate-sized event, Dr. Mansouri used a digital camera connected to a GPS unit. Therefore, all images can be tied to a specific location or geographic coordinate in the region. This report consists mostly of photos with brief explanations. A more detailed report is pending based on the data that is collected in the next several months. The purpose of this report is to provide the readers with 1) a quick summary of key statistics on the earthquake, 2) a catalog of images of the event, and 3) preliminary findings or lessons learned from the earthquake.
Key Damage and Impact Statistics
- Affected provinces: Qazvin, Hamadan and Zanjan
- 90% of Iran falls within an active seismic zone
- This earthquake was the 11th earthquake within the last two months in the central region
- 39 years ago, a more destructive earthquake occurred in this region (approximately M7.4)
- Water facilities completely destroyed in 9 villages
- 120 villages in Qazvin suffered complete destruction; 50 villages suffered 70 to 100% destruction; In Hamadan, 45 villages destroyed
- 55 schools damaged in Avaj (50 suffered more than 50% damage; 5 completely collapsed)
- Over 200 deaths in the following villages: Avaj, Abgarm, Kordehchin, Kissehchin, Hassanabad, Changureh, Abdareh, Hessarvaliassr, Aliabad, Asadabad, Shahidabad, Asnab, Azanbaz
- 25,000 people homeless
- A large earthquake in Tehran could destroy 800,000 buildings and cause a loss of $124 billion, according to Dr. Kamalian, Head of Tehran University Geophysics Department.
Updated statistics: (7/19/02)
- 226 deaths
- 1,300 injured
- 5,000 households affected
- 25,000 villagers affected
- 8 villages suffered 100% destruction
- 41 villages affected by the earthquake
- One bridge failed
- Water network damaged in all the villages with 100% damage
- Water reservoir destroyed in the villages of Imamzadeh, Alaedin and Changooreh
- Organizations involved in the emergency rescue effort: Red Crescent, military forces
- UNICEF was instrumental in providing drugs and sanitation.
Brief Background on Building Design Codes in IranAlthough there is an updated building code that is comparable to the Uniform Building Code (UBC) of the United States and also in practice for Iranian civil engineers, the application of this code is limited primarily to the larger cities of Iran. In villages, there is typically no standard for the seismic design and/or construction of buildings. Villagers tend to build their own houses at minimal cost and with minimal safety measures in place. The Qazvin region is prone to earthquakes with its most recent event occurring 39 years ago. The earthquake affected the Booeen Zahra region with devastating results. Unfortunately, little has changed in terms of the design or construction of village houses in that region compared to those that were damage 39 years ago.
Figure 3 shows a map of the towns and villages visited during this reconnaissance trip. All of the sites visited were east of the epicenter and all experienced significant damage and disruption.
Note: The map is created based on my visit and GPS measurement.
The fault line is taken from a reference (IIEES)Figure 3 Towns and Villages affected by June 22nd Earthquake
On Thursday at 5:15 AM June 27, 2002 the reconnaissance trip started from Tehran (lat 35 degrees, 48.161' & lon 51 degrees, 27.561') (odometer reading was 230882 km). I met with professor Fatemi Aghda of University of Tarbiat Moalem and a director of the Natural Disaster Research Center of Iran (odometer reading 230948 km). We headed shortly to the disaster zone of Qazvin province. At 9:00 AM (odometer 231137 km), we arrived at the historic/tourist city of Abgarm, famous for its hot springs. Nearby, Kharaghan is an ancient city with a famous monument structure that suffered damage due to this recent earthquake. But, due to time constraints, we chose another path that included most of the disaster sites. The following pictures are taken in the progressive sequence of our trip.
Village of Changooreh
A8
Changooreh bridge (near the village of Changooreh) 10:45 AM Odometer: 231178
GPS: N 35° 46.552' E 48° 58.304' elevation: 6118ft
Changooreh road bridge failed and closed to traffic. Failed abutments are shown in the circle.
A9
A10
11:00 AM GPS: N 35° 46.350' E 48° 57.871' elev. 6287ft
Failure of the columns and slabs/joists
A11
A12
Total Collapse
A14
A15
GPS: N35° 46.278' E48° 57.819'
Elevation: 6292ft
Shear cracks in walls are circled.
A16
A17
Fancy house suffered failure in most of the nonstructural walls.
Fancy house - outside wall collapsed because it lacked reinforcement.
GPS: N 35° 46.249' E 48° 57.792' elevation 6288ft
A18
A19
A20
A21
Pancaked
GPS: N 35° 46.219' E 48° 57.804' elevation: 6275 ftFirst story pancaked
A22
A23
B1
B2
All the power posts visited were intact.
B3
After visiting Changooreh, we arrived at the village of Kameshkan at 13:00PM
GPS: N 35° 44,711' E 48° 56,245' el: 6801 ft
It didn't seem devastated so we moved on to Khandaab.
Village of Khandaab
B4
B5
This school looks intact.
13:30 PM odometer: 231193 km
GPS: N 35° 42.367' E 48° 58.637' el: 7320ft
B6
B7
B8
The village from a distance
We moved to the next village (Mansoor). Only four wheel drive (4WD) trucks (such as ours) could pass through these hilly roads.
Village of Mansoor
B9
B10
GPS: N 35° 41.559' E 49° 03.717' el: 6153ft
Shrine of Ismaeel Khazaee is damaged
Then, we moved to the village of Imamzadeh Alaedin. No casualties in this village. Some houses suffered cracks.
We then proceeded to the city of Avaj. In this city, a few tents were erected in the neighborhoods with damaged buildings. Damaged buildings were of extremely poor construction. There was a new building that was damaged and received our attention (pictures below).
Key Findings and Lessons Learned
(Provided by the Natural Disaster Research Center of Iran)
Geology and Seismicity of the Affected Area
The area of interest is located in the Northern zone of Sanandaj-Sirjan. The general trend of faulting for the region is in the direction of N130 (130 degrees clockwise from the North pole). Other trends that are basically secondary are in the directions of N145, N115, N175 and N25. In Changooreh, Ab Dareh and Hessar, almost all of the mentioned trends are observable. Based on the field investigations before the recent earthquake, the main ground faulting was in the N115 direction that included reverse faults with some right strike slip components. In the recent event, however, the main trend of ground faulting is within N135-N145 that is due to synthetic rupture of the main shear zone (N130). Many instances of liquefaction occurred around the villages of Tableshkin and Hassan Abad (near Hessar). Surface fissures with various trends happened near the villages of Tableshkin, Hassan Abad, Mansoor, and Khandab. The earthquake fault is located near Changooreh and Aab Dareh. The village of Saeed Abad experienced a landslide.
Lessons Learned
Although the earthquake magnitude was high and it was generated in a shallow depth (~ 10 km below the ground surface), the surface shaking was much lower. The region is on marl stone bedrock that dampened the ground shaking considerably. Nevertheless, the main cause of the devastating destruction was due to the poor design/construction and the selection of poor building materials.
Due to the frequent occurrence of devastating earthquakes in the region, serious measures must be taken to control urban development and earthquake safe housing design/construction in the villages must be adopted.
Relevance to the U.S.
In general, there is no comparison between structural quality and construction in villages and towns in the United States and the ones in Iran. The few buildings that were constructed according to the Iranian building code were able to sustained the earthquake. Almost no structural components failed due to the shaking, but a large number of the non-structural components such as partitioning walls (masonry materials) failed and caused severe damage to the building. The study of the impact/interaction of the non-structural parts to the structural elements is very crucial in both the US and Iran (and throughout the world). This recent earthquake provided some good examples for future research. The relevance of this research to the US can be seen also in terms of further understanding the seismic activities and ground failure of seismically vulnerable countries.
References
International Institute for Earthquake Engineering and Seismology (Iran)
Natural Disaster Center of Iran
Ministry of Interior
A1
A2
A3
A4
A5
A6
A7
B11
B12
B13
B14
B15
B16
B17