Seoul City Acknowledges Construction Errors in GTX-A Line, Conducts Immediate Safety Checks

View of Seoul City Hall in Jung-gu, Seoul. 2023.09.19[Photo=Yoo Dae-gil, dbeorlf123@ajunews.com]

Seoul City has reported that it became aware of construction errors, including the omission of rebar in the GTX-A Line near Samseong Station, several months before notifying the government, prompting an audit. The city stated that it conducted immediate safety inspections in response.
On May 16, the city released a detailed report outlining the timeline of events and confirmed that safety checks and reviews of reinforcement methods were promptly initiated.
According to the city, Hyundai Engineering & Construction discovered the missing rebar during its own quality inspection process in November 2025 and voluntarily reported the issue to Seoul City.
The city noted that upon receiving this information from the contractor, it conducted immediate safety inspections at the site and comprehensively reviewed the structural stability, construction feasibility, and future maintenance implications of the reinforcement methods.
The contractor and the supervisory team reported the construction errors regarding the columns of the underground complex transfer center near Samseong Station to the city on November 10, 2025.
According to the Ministry of Land, Infrastructure and Transport, the columns for the GTX platform on the fifth underground level of the complex transfer center were incorrectly constructed with one row of main rebar instead of two, resulting in missing rebar in 50 of the 80 columns.
The supervisory team reviewed reinforcement plans on December 19, 2025, and reported them to the city. Following this, on December 30, the city established a plan for implementing structural reinforcement based on advice from external experts, in accordance with the directives of the head of the Urban Infrastructure Headquarters.
Subsequently, the city, along with the supervisory team, the contractor, and external experts, conducted site inspections and assessed the adequacy of the column reinforcement plans until March 2026.
During this period, there were 19 joint site inspections conducted by the city, the supervisory team, and the contractor, along with one advisory meeting involving external experts, including members of the city’s Construction Technology Review Committee.
On March 17, 2026, the contractor submitted the column reinforcement construction plan to the city, which then confirmed the feasibility of the plan before finalizing it. The city reported the details to the Korea National Railway Authority on April 24 and to the Ministry of Land, Infrastructure and Transport on April 29.
An emergency safety inspection led by the Ministry of Land, Infrastructure and Transport was conducted from April 29 to May 8, 2026.
According to the city, structural calculations for the reinforcement methods confirmed that the structural safety (axial load strength) would be enhanced to 60,915 kN, exceeding the original design standard of 58,604 kN. Hyundai Engineering & Construction will bear the additional construction costs, estimated at around 3 billion won.
The city plans to ensure safety beyond the original design by implementing steel plate reinforcements that are over 200% stronger than the existing rebar, along with fireproof coatings to prevent corrosion.
The city stated, "We will establish safety measures for the structure and prevent recurrence, working closely with the Ministry of Land, Infrastructure and Transport to ensure there are no delays in the GTX-A Line's non-stop service at Samseong Station. We will thoroughly investigate the causes of the construction errors and rigorously confirm accountability during the supervisory construction process, taking action in accordance with relevant laws."
The GTX-A Line is being developed with the goal of connecting Seoul Station to Suseo Station (with non-stop service at Samseong Station) by the end of this year, and plans to have a stop at Samseong Station in the second half of next year, despite the confirmation of missing rebar in the underground structures along Yeongdong-daero.
Meanwhile, the Ministry of Land, Infrastructure and Transport stated that it received reports from the city regarding the construction errors and reinforcement plans on April 29. The ministry has initiated an audit of Seoul City and the Korea National Railway Authority, citing concerns over project management due to the delayed reporting of the errors.

* This article has been translated by AI.

SoHee Baek