Circle Line Work Causes Cave-In Off Holland Road

Source : The Sunday Times, May 25, 2008

When the Sperling family went to bed on Friday night, a steel sheet had been laid across cracks in the street just outside the driveway of their bungalow, off Holland Road.

A stretch of Cornwall Gardens disappeared into a 3m-deep crater caused by 'loose ground'. While no one was hurt, water supplies to three homes were cut off and phones, computers and cable TV links were also out at one of the homes. -- COURTESY OF ELIOT SPERLING

By dawn yesterday, a 8m by 7m stretch of Cornwall Gardens had disappeared into a 3m-deep crater.

No one was injured, neither were any homes in the area damaged when the ground sank at about 4.45am, the Land Transport Authority (LTA) said yesterday.

But water supplies to three homes were cut off as the pipes snapped when the road crumbled. Phones, computers and cable TV links were also out at one of the homes because of damaged cables.

By yesterday evening, most of the crater had been filled in by contractors and repairs to affected utility lines are expected to start soon. -- ALBERT SIM

The LTA said it arranged for the homes to be supplied drinking water and provided temporary telecommunication links.

The Sperlings, whose driveway was blocked by the repair work, have been put up at Shangri-La Hotel and provided two rental cars.

Yesterday's cave-in was linked to tunnelling work taking place 22m below ground for a section of the Circle Line, connecting new stations at Holland Village and Farrer Road.

All tunnelling work has been stopped as repairs are carried out, the spokesman added.

The cave-in happened because of 'loose ground', said LTA. Its engineers and the contractors for the tunnelling work had been preparing to stabilise the soil in the area when it sank.

Residents in the area say they have experienced vibrations as tunnelling work moved through the area in the last two months.

The Sperlings, who moved into 14 Cornwall Gardens six months ago, said they could hear a constant 'low rumble'.

Housewife Jane Sperling, 46, who resides in the bungalow with her investment manager husband and three sons, said the rumble was sometimes strong enough to throw open the ceiling vents.

There were other signs.

Another resident in the area, Mr Stephen Wisely, 46, who works in an oil and gas construction company, spotted a small sinkhole in his driveway two months ago, which was later filled in by LTA contractors.

More recently, Ms Mhel Bueno, 35, a domestic help who lives at No.12, had noticed water overflowing from a pipe near the cave-in site.

The LTA said its 'engineers inspected monitoring instruments that had been installed at the houses and on the ground in the vicinity, and are satisfied that the houses and surrounding area are safe'.

By yesterday evening, most of the crater had been filled in and work was being carried out to strengthen the ground. Repairs to affected utility lines would also start soon.

The LTA apologised for the inconvenience to residents and motorists and said that the stretch of Cornwall Gardens is expected to reopen to traffic by Tuesday.

The sinkhole is the latest setback for the project, the most severe being the 2004 cave-in at the Nicoll Highway tunnel, which killed four.

Last year, four stop-work orders were issued, including for a stretch of a tunnel in Telok Blangah, when part of the road sank.

The LTA said the Cornwall Gardens repairs are not expected to delay progress of the Circle Line which is expected to be completed in stages from 2010 onwards.