MRTA to repair Samsen Road sinkhole, costing 1 billion THB, reopening in March 2027

The Mass Rapid Transit Authority of Thailand (MRTA) has unveiled its plan to repair the sinkhole on Samsen Road, caused by the ongoing construction of the Purple Line from Tao Poon to Rat Burana. The repair work, which involves a series of complex engineering tasks, is expected to cost at least 1 billion THB, with the private contractor responsible for the expenses.

The MRTA is currently awaiting the final report from the investigation committee, which is expected to be submitted to the Ministry of Transport by March 2026.

Due to the complexity of the repairs, progress has been slow, with less than 10% of the work completed. The damaged concrete structure beneath the ground requires extensive demolition and reconstruction.

The repair plan is divided into two phases:

Phase 1: The contractor will first build a 15-meter diaphragm wall around the station to block water and prevent further soil erosion. This is expected to be completed by April 2026. Afterward, water will be pumped out of the station in May 2026 to allow for tunnel wall repairs and further damage assessment.

Phase 2: A 30-meter extension of the diaphragm wall will be constructed to ensure stability, with the entire wall spanning 45 meters. This phase is expected to be completed by the end of 2026. Afterward, excavation work will begin to repair the area near the station.

Despite the challenges, MRTA is working closely with Bangkok’s city authorities to ensure that one traffic lane will be reopened by March 2027.

The overall timeline for the construction project remains on track, and efforts are underway to expedite remaining work without affecting future service schedules.