Some failures are caused by the most stealthy of human factors: corruption and greed. This situation is even worse in the third-world countries where the use of sub-standard materials, faulty construction methods and cutting corners around standard specifications is highly prevalent.
In this post, the influence of societal failure on structural failures will be explored using the events surrounding the collapse of the Sampoong Superstore in South Korea in 1995.
Originally designed as an office building, the five-storey, bright pink superstore was not without controversies. It was constructed on landfill, and Woosung Construction designed the building’s foundations and basements. But issues emerged as Woosung rejected planned changes to the use of the building – it would be modified from office to retail and added
All went fine for five and a half years, but by mid-1995 it became obvious that everything about the structure was really wrong. Major cracking in the roof slab was found on the morning of 29 June. At some point earlier, heavy air-conditioning systems, which were initially situated on the east side of the building, were moved west due to noise complaints. The units were actually dragged onto the roof floor, instead of being raised by crane. It would transpire that the slab had just one-quarter of the capacity needed to accommodate the units and that the roof had been heavily compromised. At column locations cracks had opened up to 25 mm wide.
Engineers were eventually called in to investigate, and they recommended the evacuation of the building. However, executives at the organization agreed otherwise. Over the course of the day, the cracks worsened and spread. The air conditioning systems were switched off as vibration seemed to be making it worse. At 6 pm the building could take no more, and the 91m long north wing of the store suddenly collapsed (Figure 1). Only the two end walls of the structure remained standing. There were 498 fatalities.
Causes of Failure
Whilst it could’ve been argued that the failure was actually set in motion by the movement of the air conditioning units, however, bribery and corruption had ensued a deficient structure from the outset. One of the main problems was the decision to modify the function of the building from office to retail without reassessing the structural design, which consisted of columns and slabs without supporting beams (flat slabs). The transition to retail resulted in major limitations being added, such as the construction of escalators requiring wide openings to be made in the flat slabs. But it was indeed, the replacement of the proposed skating rink on the fifth floor with the conventional Korean restaurant that created the real problem.
Traditional Korean restaurants have no chairs – patrons normally sit on the floor. So, when the decision was then taken to add in-floor heating, this involved the construction of a 900 mm deep concrete floor. This extra concrete added substantial mass to the structure and raised the dead load on the fifth floor by 35%. To make matters worse, columns were either completely removed or relocated to suit the architectural needs of the building, leading to a condition where columns no longer aligned with those below. The flat slab was now playing a critical structural role in transferring column loads between the floors. At the end of the day, the cause of the failure was the modifications brought on by the “illegal modification of the architectural style and use of the structure”.
Although this may have contributed to a disaster, these unlawful modifications were just the tip of the iceberg when it came to non-compliance with the structure’s specification. For starters, the 890 mm thick columns were actually 610 mm thick. They had just 8 as opposed to 16, reinforcing bars. In other instances, reinforcement were actually been omitted. Concrete strength was just 18MPa when 21MPa was specified. And these changes were made possible by corruption – 12 local building authorities were found guilty of taking bribes for approval of modifications and issuing temporary certificates of use. They were paid in excess of US$ 17,000.
The collapse and loss of life caused outrage in Korea, leading to an investigation of the construction industry. The investigation found an endemic level of corruption, which was historical. Korea’s building industry was thriving in the 1980s, and there was tremendous pressure on companies to perform – a situation compounded by a government veto that prohibits contracts from being signed overseas. Then Seoul was awarded the 1988 Olympic Games, further stressing the situation. Such an environment was ripe for abuse, and the construction of the Sampoong Superstore occurred in the midst of this rush.
Though it was to become the most noticeable disaster, the issue was even wider: the South Collapse of Sampoong Superstore, South Korea. The survey of high-rise buildings by the Korean government indicated that only 2% met the standards; 84% needed repairs and 14% deemed unsafe and required reconstruction.
The Sampoong Superstore tragedy teaches us that a malfunction happens every once in a while and has an impact well beyond the rubble and the devastating loss of life. Such shortcomings cause us, as a society, to look more deeply at ourselves. Sampoong collapse exposed widespread corruption in Korea in the 1990s, however, the situation is far worse in the developing countries today. In fact, to say that the level of corruption in the construction industries of developing countries is endemic would be a gross understatement, it’s indeed ” more than a pain in the rear”. Almost all of the causes of structural failures in developing countries particularly Nigeria can be traced back to bribery and corruption.
In 2019 alone, over 43 building collapse cases was recorded in Nigeria and over 36,000 potential collapse waiting to happen. The journey is very far and long and far from complete especially for those in the third world countries but the Sampoong superstore tragedy should remind us that any time we open our wallets in today’s globalized economy, the transaction is not just monetary but also moralistic.
Delatte N. J. (2009) Beyond failure: forensic case studies for civil engineers, Reston, USA: ASCE Press
Building Collapse Prevention Guild -2019 (BCPG) (Annual Report)
Thank you, please share!