Seoul's Sampoong Superstore Collapse
System Life Cycle
Concept
Construction
Operating
Maintenance
Decommissioning
Modern department store to suit Seoul's booming economy. Management added an unplanned 5th above ground floor during construction.
The original design was for 4 underground level and 4 above ground level.
Flat Slab Construction: Concrete columns support weight of each concrete slab level and reinforced with steel bars.
Engineering calculations determined that each column needed to be 80cm in diameter and that steel bars be placed 5cm from the surface of the concrete slabs.
Architect design caused the columns to be 60cm in diameter and the steel bars were place 10cm from the surface of the slabs.
Employs over 1000 staff
Serves over 40,000 customers daily
Stocks everything from electronics to fashion
Turns over 4 million US dollars each week
Most exclusive retail store was a symbol of Seoul's economic prosperity.
Prior to collapse the complex had passed a safety inspection.
Healthy safety tolerance as the engineering design made the building 2.5 x stronger than necessary.
Systematic disregard for building regulations.
Building safety was a major concern in South Korea due to multiple other structural collapses.
Rescue efforts lasted 1 week before the clean up process began.
Investigations began almost instantly.
⭐WHAT⭐
-In 1993 the air conditioning units were removed
-A security guard hears strange noises from the roof and leaves the manager a note.
-The manager investigates the roof to find large cracks.
-5th floor concrete slab has a large crack around the base of a column. The floor has buckled.
-Building vibrates. Assumed cause is the air conditioning so they are switched off.
-Cracks continues to widen.
Store owner refuses to close the complex
-Several loud bangs are heard from the 5th floor and the ceiling shifts
-Shock wave rock the entire complex
-Emergency alarms go off
-Building has collapsed in under 20 seconds
-Only the North wall of the building remains standing.
-Rescue efforts began almost immediately and ceased after 1 week
-937 people were seriously injured
-502 people died
2 years prior to the collapse, air conditioning units were removed from the roof due to noise complaints.
The air conditioning units were removed by dragging them across the roof causing instability.
⭐WHEN⭐
⭐WHERE⭐
⭐WHO⭐
Owner - Joon Lee; aged 73
Manager - Mr Hang-San Lee; aged 42 (son of owner)
Engineer and Architect - names unknown
Chief Investigator - Professor Lan Chung
Seoul, South Korea
Sampoong Super Store
June 29th, 1995
Building collapsed at 5:52pm
System Failures
People
Workplace
Management
Individual Factors
Denial and greed of the owner would not allow the store to close despite all the signs.
Architect and Engineers were fully qualified to design/build the structure.
Customers expected the super store to be safe and built according to Seoul's building regulations.
Management staff did not pay great attention to the structure integrity and simply ignored signs of damage e.g. cracks, loud noises
The management team was driven by commercial pressure and greed to build a revolutionary department store that met the demands of the high-class city.
The construction team and supervisors were bribed to overlook certain factors during the building, therefore it is unclear if some workers rights were overlooked causing fatigue or stress. Their disregard for building policies would have also endangered the workers.
Organisational Factors
The management and in-house construction crew completely disregarded building policies and procedures.
Management chose to section off areas on the top floor once the floor buckled, however they refused to close the complex as the conditions worsened.
The owner decided during construction the another floor was required despite safety warnings.
Job Design
Employees of the store were assigned to certain departments ranging from electronics to fashion
Construction supervisors "looked the other way" with incorrect procedures due to bribes.
Employees are required to be constantly standing throughout the shift. On the day of the collapse the air conditioning was switched off causing fatigue and dehydration.
Information Transfer
Gossip about the structurally integrity of the building despite the manager ordering employees to remain quiet.
No communication about the disregard for the buildings construction until after the collapse of the super store.
Workplace Factors
The super store had 4 underground levels and 5 above ground levels
Was built on an original waste dump site
The 5th floor contained 8 restaurants which required the installation of floor heating, increasing the weight.
The vital connection of the concrete slab to the column, where the stress is transferred to the ground, was weak.
Equipment Design
Flat Slab Construction: Concrete columns supported the weight of each concrete slab level and reinforced with steel bars.
Engineering calculations determined that each column needed to be 80cm in diameter and that steel bars be placed 5cm from the surface of the concrete slabs.
Architect design caused the columns to be 60cm in diameter and the steel bars were place 10cm from the surface of the slabs.
Emergency alarms were triggered as a shock wave began the collapse of the building.
Cracks were left in the roof when the air conditioning units were removed 2 years earlier.
Due to multiple previous structural collapses safety inspections and correct building practices were a major concern.
Even with customer and employee feedback, management refused to accept that anything was wrong.
Work Environment
2 years before collapse, air conditioning units were removed, due to noise complaints, leaving cracks in the roofs and making the building unstable.
Every time the new air conditioning system was turned on vibrations went through the building, widening cracks and decreasing the structural integrity.
Hot and humid summer days.
Due to the air conditioning being switch off temperatures within the department store reached 32 degrees Celsius.
The loud bangs were coming from the 5th floor before the ceilings shifted.
System Parts
Environment
Hot summer days
Air Conditioning was switched off inside the store
Temperatures reached 32 degrees Celsius
Construction
Management added a 5th above ground floor with extra heating
Precondition
Concrete Columns were built smaller. Steel bars were placed an additional 5cm below the surface of the concrete slabs.
Vital connection between the concrete slabs and columns was weakened
Latent Failure
Removal of the air conditioning units 2 years prior to the collapse created cracks and instability withing the building
Active Failure
Superstore
1000 employees
Turned over 4 million US dollars each week
Precondition
Demonstrates Seoul's economic prosperity
Latent Failure
Management team refused to close the store
Active Failure
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Australian Transport Safety Bureau (ATSB) 2016
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