Transport Ministry to launch audit into Seoul gov't after construction defect was found at GTX platform

After multiple underground support columns along the tracks for the Great Train Express (GTX)-A line were found to be missing a row of rebar, the Seoul Metropolitan Government pledged on Saturday to install additional reinforcements. The Ministry of Land, Infrastructure and Transport has already launched an audit into the city government.

“To improve safety, steel reinforcement plates with more than twice the strength of the originally intended rebar will be installed,” the Seoul city government said in a statement.

“We intend to secure structural stability exceeding that of the initial design through both internal and external reinforcement,” the city government added.

Last year, Hyundai Engineering and Construction found that 50 of the 80 support columns at the GTX platform — located on the fifth basement level of Samseong Station’s transit center in Gangnam District, southern Seoul — have only one layer of metal beams, despite the original design calling for two. 

As a result, the columns, designed to withstand 58,604 kilonewtons of force, reportedly have an actual load capacity of around 50,695 kilonewtons. 

“The construction firm [...] discovered the issue during an internal quality inspection in November of last year and voluntarily reported it to city authorities,” the Seoul city government said.

The city subsequently launched an on-site safety inspection and established a plan for the affected columns that December.

“The contractor submitted its final construction plan for reinforcing the affected columns on March 17,” the city said. “After examining its on-site applicability, the [related authorities] finalized the plan in April and handed it to the Korea National Railway and the Ministry of Land, Infrastructure and Transport.

“The Transport Ministry also conducted an additional emergency safety inspection of the structure.”

“Experts have confirmed that the reinforced structure will provide a higher level of safety than what was required under the original design’s standards,” the city added. “Structural calculations confirmed that the reinforced structure would withstand 60,915 kilonewtons, above the original standard of 58,604 kilonewtons.

“The additional construction cost of about 3 billion won [$2 million] will be fully covered by Hyundai Engineering and Construction.”

According to the city, it will work closely with the Transport Ministry to complete the construction work while ensuring that there are no disruptions to the operating schedules of GTX-A trains passing through Samseong Station.

However, the Transport Ministry began an audit of the Seoul city government and the Korea National Railway on Friday after determining that the city had taken around five months to report the defects to the ministry, despite becoming aware of them last November. The ministry will also seek an external review of the city’s reinforcement plan through a certified agency.

The GTX-A train connects Dongtan in southern Gyeonggi to Paju in northern Gyeonggi, passing through Suseo Station, Samseong Station and Seoul Station on the way. The underground train operates at a maximum speed of 180 kilometers (112 miles) per hour.

“We will execute additional detailed safety inspections and reinforcement measures,” the city said. “We will also thoroughly investigate the cause of the construction error and determine responsibility accordingly.”

The issue has escalated into a political flashpoint ahead of the June 3 local elections.

“When such a serious construction defect was discovered, all construction work should have been suspended while authorities reviewed safety measures and reinforced the structure before proceeding further,” said Chong Won-o, the ruling Democratic Party’s candidate for Seoul mayor. “[Incumbent mayor Oh Se-hoon] must explain when he first received reports of the faulty construction and what steps he took afterward.” 

Oh, who represents the main opposition People Power Party and is running for re-election, said, “The Hyundai Group is carrying out the reinforcement work at its own expense and responsibility.”

“The circumstances surrounding the construction error only became public because Hyundai Engineering and Construction itself acknowledged and reported the issue. The Chong Won-o campaign seems eager to turn an ordinary mistake by a construction company into a political controversy,” he said. 

BY KIM EUN-BIN, KIM MIN-WOOK [lee.soojung1@joongang.co.kr]