Bangkok sinkhole repair halted after 1,500 tonnes of concrete leak into tunnel

BANGKOK: Bangkok governor Chadchart Sittipunt confirmed on Friday (Sept 26) that emergency work to repair the major road subsidence on Samsen Road has been complicated, revealing the operation was halted after 1,500 tonnes of poured concrete leaked into the underground tunnel network.

The governor visited the site in front of Vachira Hospital on Sept 26 to oversee the operation, where he confirmed to the press that approximately 1,500 tonnes of concrete had been poured overnight to seal the breach.

However, the pouring was immediately suspended after technicians discovered that a portion of the cement had flowed into the subterranean tunnel below.

The governor explained that engineers must now wait for the initial concrete fill to dry and set before resuming the operation later today.

They estimate that up to 2,400 tonnes of concrete will be required in total before the next phase—constructing a permanent structural concrete wall—can commence.

While the sinkhole itself remains stable, the governor noted that a 50cm soil slide had occurred overnight, though it caused no further damage or injuries.

The structural safety of surrounding buildings remains a major concern. The adjacent Samsen Metropolitan police station and nearby residential flats remain sealed off.

To monitor potential movement, experts from Kasetsart and Chulalongkorn Universities have installed additional equipment to track the building’s vibrations, as the police station lacks a retaining wall.

In stark contrast, Vachira Hospital resumed normal outpatient services at the Tipangorn Rasamichote Building after the area was deemed safe.

The hospital’s structure benefits from deep piles and a retaining wall, which sits a safe six metres away from the subsidence zone.

Officials were dispatched into the tunnel today to survey the damage, which includes a 30sq m breach in the tunnel wall. The landslide also trapped two police vehicles—a tow truck and a private car—inside the station’s lower level.

The Mass Rapid Transit Authority of Thailand (MRTA) has confirmed it will retrieve the vehicles after the repairs are complete and will purchase brand-new replacements for the owners.

With a 70 per cent chance of rain forecast for Bangkok today, particularly in the eastern zones like Min Buri and Nong Chok, the governor confirmed that flood mitigation efforts are underway at the sinkhole site.

Four high-capacity water pumps and sandbag barriers have been installed around the perimeter to prevent rainwater from accumulating in the excavated area.

Despite the disruption, morning traffic on major arteries like the Krung Thon Bridge (Sanghi Bridge) was reported as heavy but moving well, with established diversions in place to navigate around the closed section of Samsen Road. – The Nation/ANN