Sinking Gimpo Airport and Squeaking Construction

Korea’s Gimpo Airport hosts dozens of international flights a day. Its tarmac, however, has been deteriorating for years, threatening the safety of airline passengers.

But the Korea Airports Corporation (KAC) in charge of its management closed its eyes to the sloppy works until recently. The corporation had sided with the construction company responsible for tarmac conditions. Faced with mounting criticism, the state-run corporation belatedly acknowledged the problem and ordered the contractor to renovate the tarmac.

United Democrat Congressman Han Byung-do revealed the problem yesterday, citing information provided by the KAC. According to Han, 880,000 square meters of tarmac has eroded. The KAC has retained a constructor to repair it.

A tarmac refers to a paved area used for passenger boarding and airline taxiing.

The tarmac first began to crack in April 2004.

At that time, two subway lines were being constructed underneath the tarmac, which weakened the tarmac foundation. Consequently, 68 concrete slabs (7.5m x 7.5m each) near the engine test area began to crack or cave in.

The KAC charged subway constructor Hyundai Construction for repairs, and Hyundai stopped drilling to restore the tarmac near the end of 2004.

When the drilling resumed in May 2005, 700 slabs, a number 10 times larger than that of the originally damaged slabs, caved in. Further, 22 of the fixed 68 slabs cracked again.

Worse, the drilling for Metro Line 9 damaged 800 slabs. Some slabs sank as deep as 35 cm lower than others.

In a written memo sent to Han in June this year, the KAC stated that repairs had completely restored the tarmac.

The latest memo said that the tarmac was now completely level. Suspicious, Han retained college engineering professor Lee Chang-gyung and had him examine the tarmac. The professor found out, however, that some slabs were up to 10cm lower than others. He concluded that the repairs were not as complete as reported.

Moreover, the professor figured out that requirements in the specifications were not met. To restore a slab, the concrete slab has to be lifted first, and the space has to be filed with cement or urethane. The contractor, however, chiseled off high-lying slabs, while filling the lower ones with concrete.

Small dirt particles can hamper plane engines and cause a disaster. Thus, most international airports prohibit artificial leveling through grounding or filling.

Professor Lee lamented, “It’s not that difficult to keep the slabs level. I don’t understand why they show that much variation.”

A KAC officer responded, “We did not notice the problem. The inspector submitted an incomplete report. We examined the slabs again, and found 150 defective slabs. We ordered the constructor to fix the problem.”

Rep. Han suspects that the KAC failed to manage the repairs properly, and plans to refer the case to the Board of Audit and Inspection for further scrutiny.

egija@donga.com