LESSONS FROM KASHMIR 2005 EARTHQUAKE

PRESENTED BYHASSAN Y. MAHMOUD

1101065

Cairo University Faculty of Engineering

SEISMIC DESIGN OF STRUCTURESSTRN437

HISTORICAL INFORMATION• On October 8, 2005, at 8:50 a.m. local

time, a magnitude Mw = 7.6 earth-quake

struck the Himalayan region of northern

Pakistan and Kashmir. The earthquake

epicenter was located approximately 19

km north northeast of the city of

Muzaffarabad, the capital of the

Pakistani-administered part of Kashmir,

known as Azad Jammu Kashmir (AJK).

• Kashmir 2005 earthquake is

similar in size to the 1906 San

Francisco earthquake, the 1935

Quetta earthquake, the 2001

Gujarat earthquake, and the

2009 Sumatra earthquakes.

NUMBERS AND FACTS• Over 1000 aftershocks were recorded; ranging from 5.0 to 6.0 on

the Richter scale.

• left an estimated 3.3 million homeless in Pakistan alone.

• The total area affected was 30,000 km2. (66 times area of Cairo).

• included a range of unprecedented damage and destruction, such as:

1. 500,000 Houses

2. 365 Medical facilities

3. 13% of the power lines

4. 6083 Schools/Colleges

5. 1000 Hospital

• Total 780,000 structures were either destroyed or damaged beyond repair.

CAUSES OF THE EARTHQUAKE• Seismic activity in South Asia is a direct result

of the collision of the Indian and the Eurasian plates, which results from the

northwestern motion of the Indian Plate at the rate of 4-5 cm per year.

• The resulting collision has fractured the Indian

plate into several slices beneath the Kashmir Basin and is known as the Indus-Kohistan

seismic zone.

• The main identified feature in this zone is the

Balakot-Bagh fault, which is the likely source of the earthquake.

Why did the earthquake happen there?

CAUSE OF DAMAGE

"In the known historic and recent records, not one of the earthquakes in the Himalaya has

ever produced a surface rupture, not in Nepal, or India, or anywhere. This rupture was the

first one.“-Robert Yeats

CAUSE OF DAMAGE• Sudden and rapid releases of seismic stress can cause

large earthquakes. And sometimes, an abrupt movement along a shallow fault can rupture the surface, as happened during the 2005 Kashmir earthquake. This surface rupture extended for seventy-five kilometers and was a first among earthquakes in the Himalaya seismic zone.

CAUSE OF DAMAGE• 30-45 seconds of strong shaking.

• The reported focal depth for this event ranges from 13km (MSSP), to 20km (USGS), to 26km (IGS).

• Strong motion records in Abbotabad (35 km from rupture zone), Murree (34 km), and Nilore (54 km) show maximum horizontal peak ground accelerations (PGA) of 0.231g, 0.078g and 0.026g, re-spectively; and vertical PGAs of 0.087g, 0.069g and 0.03g, respectively

• Within the surface rapture zone mentioned previously:

1. Muzaffarabad suffered great damage (IX-X on MMI scale)

2. The city of Balakot was almost totally destroyed (X on MMI scale).

• The distribution of subsequent after-shocks, in the Balakot, Batagram, Allai, and Beshram Qila areas, suggests that the fault rupture extended in the NW direction.

LANDSLIDES• Landslide concentrations along the rupture zone were

very high, but quickly dissipated within as little as 2 km of the surface projection of the fault.

THE EFFECTS OF THE EARTHQUAKE• As Saturday is a normal school day in the region, most

students were at schools when the earthquake struck.

• Many were buried under collapsed school buildings.

• Many people were also trapped in their homes and, because it

was the month of Ramadan, most people were taking a nap

after their pre-dawn meal and did not have time to escape

during the earthquake.

THE EFFECTS OF THE EARTHQUAKEBuildings were destroyed, people injured and ended up without homes.

THE EFFECTS OF THE EARTHQUAKE• Roads buried in rubble hampered relief

efforts in many remote villages and many affected areas remained inaccessible.

• Numerous aftershocks that continued to rattle the region affected rescue efforts put rescue workers in danger

• In many areas power went out while people also lacked adequate food or water

• The danger of disease spreading,

including measles increased dramatically.

• On October 13, snow started to fall on the Indian side of Kashmir. Many regions faced an increasing threat of being cut off from help as snow forces closures of even more roads in the mountainous region.

STRUCTURES• Most building damage resulted from ground shaking

• large number of buildings located mostly on or near slopes were destroyed by ground failure due to landsliding or subsidence

• Most of the buildings in the affected area are of nonengineered unreinforced masonry (URM) wall construction

• The smaller villages also contain adobe structures that, as expected, performed poorly in the earthquake.

• The only steel reinforcing found in most of the bearing wall construction is in lintels (window ordoor headers).

• The performance of the URM wall buildings in the earthquake was varied

STRUCTURESIn areas of strong shaking, most stone masonry-bearing wall structures collapsed or suffered severe damage.

STRUCTRUES• Framed construction: A small

percentage of buildings in the area

• The floors are mostly of beam and slab construction supported by columns resting on pad foundations.

• There is no lateral force resisting system

• After the earthquake a lot of these framed structures were resting only and entirely on “nonstructural” infill walls while the columns had failed just below the first elevated floor.

STRUCTURES• Within the earthquake-

affected zone, the most prevalent bridge type was suspension bridges.

• The suspension bridges are typically for pedestrian use.

• Damage to suspension bridges ranged from shearing of the tower foundation to complete collapse of the towers.

POOR POST-EARTHQUAKE ASSESSMENT• A major hospital in Abbotabad, the Ayub Medical College, was

a critical care facility lost due to lack of a proper post-

earthquake assessment process.

• Due to lack of qualified personnel, a num-ber of homeowners

uncertain about the safety of their homes temporarily relocated

to distant towns or tents, even though their homes did not

appear to have any significant damage.

SEISMIC PLANNING AND CODE• The area that suffered in the earthquake was either not classified

or was deemed to be Zone 2 (equivalent to UBC Zone 2: low to moderate risk).

• This classification was not done according to the criteria mentioned in the UBC.

• According to the criteria these areas are in zone 4.

• Seismic hazard is not given a great deal of attention in urban planning and policy decisions, and seismic design does not appear to be high priority, except for major or high profile projects.

• the development of a proper national building code with appropriate seismic design provisions had been out-sourced to local consultants after that catastrophic loss.

RECONSTRUCTION• In late 2006, Pakistan approved $20 billion development

scheme for reconstruction of the earth-quake hit zones in Azad Kashmir. A land use plan for Muzaffarabad city had been prepared by Japan International Cooperation Agency.

Pakistan established the Earthquake Reconstruction & Rehabilitation Authority to rebuild the area

ANY QUESTIONS?

/hassanyahya92These slides are available on my Slideshare