All lanes shut between Wongwian Yai and Ban Khaek after Purple Line tunnel leak
Authorities have closed all traffic lanes between Wongwian Yai and Ban Khaek intersections after water seeped into a Purple Line tunnel, causing road subsidence and cracks, while DDPM rescue and pumping units stand by.
All traffic lanes between Wongwian Yai and Ban Khaek intersections have been closed after water seeped into a tunnel under construction for the MRT Purple Line southern extension, causing the road surface above to subside and develop visible cracks.
The Department of Disaster Prevention and Mitigation has ordered structural-collapse rescue vehicles, rapid-response rescue vehicles and long-distance water pump trucks to stand by at the scene in case the situation worsens.
Deputy Interior Minister Worasit Liangprasit and Deputy Transport Minister Siripong Angkasakulkiat on Thursday led senior officials to inspect the affected area around Wongwian Yai intersection. The delegation included DDPM director-general Theerapat Kachamat, Department of Public Works and Town & Country Planning director-general Phongnara Yenying, a Bangkok Metropolitan Administration deputy permanent secretary, and DDPM deputy director-general Saharat Wongsakulwiwat.
DDPM deploys rescue vehicles and long-distance water pumps
Officials said the road section from Ban Khaek intersection along Prachadipok Road towards Wongwian Yai had been completely closed to traffic for public safety while engineers assess the condition of the road and surrounding commercial buildings.
The inspection followed a water leak inside the Purple Line construction tunnel, which caused subsidence on the road surface and raised concerns over possible structural impacts in nearby buildings.
Engineers assess nearby buildings and tunnel safety
According to an earlier report, a follow-up inspection found the road surface near the southern Purple Line construction site had subsided by a further 20 centimetres. Officials also found slight tilting in some nearby buildings and possible new cracks, although authorities said evacuation was not yet required. The seepage was believed to have come from a joint of a sump pit beneath the tunnel, while pumping and ground-improvement work were underway to control the water flow.
Siripong said engineers were considering several repair options, including sealing both ends of the tunnel and adding water to balance internal and external pressure, as well as injecting fast-setting chemically mixed concrete from outside the tunnel to strengthen the structure.
The affected area is part of Contract 4 of the MRT Purple Line southern extension, covering the Saphan Phut–Dao Khanong section. The 14.982-billion-baht contract is being carried out by Unique Engineering and Construction Public Company Limited, or UNIQ.
DDPM said teams from Disaster Prevention and Mitigation Centre District 1 in Pathum Thani had been ordered to deploy personnel and specialist equipment to the site. The equipment includes long-distance water pump trucks, structural-collapse rescue vehicles, rapid-response rescue vehicles, high-mast mobile lighting trucks with a minimum height of 9 metres, 10,000-litre water tanker trucks for firefighting support, and Emergency Response Team personnel.
Authorities are urgently surveying the road structure and nearby buildings to prepare a repair plan and determine when the area can safely return to normal use.
Motorists have been advised to avoid Ban Khaek intersection, Prachadipok Road and Wongwian Yai until further notice, and to follow official traffic updates.
