Essential soil safety tests at the Samsen Road sinkhole site in Dusit district are delaying its filling-in, as the demolition of adjacent Samsen police station continues, Bangkok Governor Chadchart Sittipunt said at the site on Monday morning.
As of Monday morning, about 4,000 cubic metres of sand had been dumped into the giant hole on Samsen Road. Its depth had decreased from about 20 metres to about 15 metres. (continues below)
Officials were boring six holes in the dumped sand and taking core samples to ensure safety before proceeding with the filling-in and beginning the repair of Samsen Road.
Mr Chadchart said that safety procedures were necessary and would lead to effective repairs that would prevent further excavation at the site after Samsen Road reopens and construction of the underground Purple Line electric railway extension resumes there.
The demolition of the relatively new four-storey Samsen police station continues. The damaged structure teeters on the edge of the 30-metre-long hole, which sucked soil and some support pillars from beneath the police building. The building had many large cracks, some collapsed outer walls and tilted floors on Monday morning.
The steel roofing was removed on Sunday night. Engineers reported that the soil under the police station remained stable on Monday.
The Bangkok governor said the adjacent Samsen police flats and Vajira Hospital remained secure.
He also said that building repairs were the responsibility of the Mass Rapid Transit Authority and its contractors handling the extension of the Purple Line under Samsen Road.
It was still not clear when Samsen Road could be reopened to traffic, Mr Chadchart said.
The subsidence occurred suddenly in the morning of Sept 24 above an underground station under construction for the Purple Line extension route. The state-run MRTA blamed it on the soft soil in the area.