Another Ground Subsidence Hits Busan Deep Tunnel Section... Complete Road Closure Near Naeseong Underpass

Additional Sinkhole Appears at Site of Major Repairs in April

GS Engineering & Construction and Busan City Launch Emergency Investigation and Begin Second Round of Repairs

Another ground subsidence (sinkhole) incident occurred on a road near the Manduk~Centum Deep Underground Tunnel construction site in Busan, resulting in severe traffic congestion in the city center over the weekend. This latest accident is particularly concerning as it happened at the same location only about a month after extensive repair work was completed last month, heightening anxiety among local residents and drivers.

On the 17th, a ground subsidence occurred on the road near Naeseong Underpass in Dongnae-gu, Busan, resulting in the closure of vehicle traffic on the entrance ramp heading toward Myeongnyun. Photo by Yonhap News.

According to Busan City on May 17, at approximately 9:18 a.m., the ground subsided, creating a level difference on the road near the access ramp toward Myeongnyun-dong at Naeseong Underpass in Dongnae-gu, Busan. Upon receiving a report, Busan City, concerned about safety accidents, immediately closed both lanes of the Myeongnyun-bound access road and subsequently blocked one lane of the opposite-direction exit road as well. As a result of the incident, traffic in the Naeseong Underpass area experienced severe congestion throughout the day.

The area that collapsed this time is the same section where a large-scale sinkhole appeared on April 5, prompting Busan City to carry out major emergency restoration work. With additional subsidence occurring at the same site just a month later, officials from Busan City and GS Engineering & Construction, the contractor for the section, rushed to the scene to begin a detailed analysis of the cause and assess the extent of the subsidence. Authorities immediately commenced a second round of repairs starting at 12:30 p.m. on the same day. They set a recovery schedule to resume vehicle traffic on the Myeongnyun-bound access road first at around 10:00 p.m. that evening, and to fully reopen the exit road in the opposite direction by 4:00 a.m. on the 18th.

The problem is that this is not the first time ground subsidence has occurred in this section. On April 5, simultaneous ground subsidence occurred at six locations, including four spots along the Naeseong Underpass—which is part of the Manduk~Centum deep-level tunnel construction route—and two on the Suyeong Riverside Underpass in Haeundae-gu, causing long-term traffic control. Additional subsidence was observed the next day, April 6, on the Suyeong Riverside Underpass in the direction of Banyeo-dong.

At that time, Busan City suspected that backfilling work after the deep underground construction had been insufficient. The city conducted a two-week detailed investigation using ground-penetrating radar (GPR) equipment, but ultimately failed to locate any underground voids (empty spaces). However, despite the announcement that no voids were found, the upper road surface above the construction site subsided again just a month later, fueling controversy over poor restoration by the contractor and increasing calls for a comprehensive review of the structural safety of the deep-level tunnel project itself.

This content was produced with the assistance of AI translation services.