MRTA construction director Wacharapon Khongsawad said on Wednesday (Oct 15) the original sinkhole was 30 metres wide, 30m long and 20m deep, but had since expanded and was still getting bigger, reports the Bangkok Post.
The initial estimate that about 8,000 cubic metres of sand would be needed to fill it was now inadequate. It would need more than that. Filling the hole was clearly a race against time, he said.
The sand fill would strengthen the foundation of the damaged Samsen police station building, which would be demolished. It would also speed up the reopening of that section of Samsen Road to traffic in time for the new school semester.
When the fill was complete and the road reopens, the demolition of Samsen police station building could gain pace. But it would require partial road closures at times.
By Wednesday the depth of the hole had been reduced to about 4.5 metres. Engineers were closely monitoring adjacent buildings for safety.
The sinkhole formed on Samsen Road in Dusit district, Bangkok, in the morning of Sept 24 above an underground railway station under construction for the Purple Line extension route of the MRTA. The state enterprise blamed the subsidence on the water saturated, soft soil in the surrounding area.