No drains, tarmac soft, say experts   (Published in the BangkokPost.com week of Feb 11th 2007)

More taxiway damage found after repairs

AMORNRAT MAHITTHIROOK

A drain should have been put in place to take water from beneath the taxiways and runways of Suvarnabhumi airport, says an expert investigating problems there.

Foreign engineers might not be aware that the airport's site was once a swamp, said the expert, who asked not to be named.

"The panel investigating problems at the airport must look into what was known about water levels," he said.

Sand had been used to fill swamp during construction of the airport, but an embankment around the airport, which was built later, complicated the problem as it in effect held water inside the enclosed area, stopping it from draining out.

A member of the inquiry panel, Suebsak Prombun, said his group was investigating the cause of problems there, but was not responsible for bringing those responsible to justice.

At this stage the committee believed that cracks and subsidence in the taxiways had been caused by underground water which had existed since construction of the airport began.

The committee proposed installing an efficient drainage system, and digging shallow wells in the airport to hold and drain water.

Thiti Paveenachana, an expert from the Engineering Institute of Thailand, said one study found that 80% of damage had been found on the northern taxiways.

Underground drainage systems should be checked to see if they were clogged. Clogged pipes could cause trouble to the surface areas.

Mr Thiti suggested standard construction materials be brought in to repair the runways, and solutions to the water problem should be hammered out at the same time.

Another source from the investigation panel said damage was still being found at taxiways T15 and T17, despite repairs having already being made.

The damage was caused by ruts left on the surface by aircraft wheels.

The committee linked the damage to substandard materials used as components for paving the surfaces, the source said.

The panel would propose strengthening areas that have to bear the weight of aircraft.

The source added the panel's study indicated that some water in the sand layer under the airport was natural underground water.

However, rain water was also seeping through holes in the runway into the sand layer beneath.

A source from IOT Joint Venture said the wheel ruts problem was linked to the quality of asphalt, which was "too soft".

IOT is the consortium that comprises Italian-Thai Development Plc, Obayashi Corp Ltd and Takenana Corp Ltd. It was responsible for designing and building the south airside tunnel and airfield pavement at Suvarnabhumi airport.

Deputy Transport Minister Sansern Wongcha-um said the ministry was waiting for the findings of the committee headed by Tortrakul Yomnak, a board member of Airports of Thailand Plc.

The ministry would then decide which parts of the airport should be repaired.

Bannawit Kengrian, chairman of the National Legislative Assembly's committee on Suvarnabhumi airport, said the airport should be completely closed for repairs.

Don Muang airport was fully prepared and low-cost airlines were willing to move there. Adm Bannawit said Suvarnabhumi would eventually close for repairs as no airline would dare use airports with cracks.

He said he would discuss the relocation of low-cost airlines, and domestic and international flights at the next cabinet meeting, if damage were found at both runways at Suvarnabhumi.

The government will decide the airport's fate on Wednesday. Earlier, Prime Minister Surayud Chulanont said he would prefer the airport to remain open while the problems were corrected.