The massive sinkhole on Bangkok’s Samsen Road will require far more sand to fill than originally estimated, as it continues to expand, according to the Mass Rapid Transit Authority (MRTA).
MRTA construction director Wacharapon Khongsawad revealed on Wednesday that the sinkhole initially measured about 30 metres wide, 30 metres long, and 20 metres deep. However, it has since grown larger and remains unstable.
The original estimate of 8,000 cubic metres of sand is now inadequate, and additional material will be needed. Wacharapon described the effort as “a race against time” to stabilize the area and prevent further damage.
Filling the hole will also strengthen the foundation of the nearby Samsen police station building, which suffered structural damage and is slated for demolition.
The project aims to allow the affected section of Samsen Road to reopen to traffic in time for the upcoming school semester.
Once the fill work is completed and the road reopens, demolition of the police station building can proceed more quickly, though partial road closures will still be necessary at times.
As of Wednesday, the depth of the sinkhole had been reduced to about 4.5 metres. Engineers are monitoring nearby buildings closely to ensure safety and structural stability.
The sinkhole formed early on the morning of September 24 in Bangkok’s Dusit district, directly above the construction site of an underground railway station being built for the MRTA’s Purple Line extension project.
The MRTA attributed the incident to the area’s water-saturated and soft soil, which caused severe ground subsidence and structural instability.
