More pockets found amid subway construction

The Seoul city government yesterday announced that it had found five more empty pockets under the Seokchon Underpass in Songpa District, following its discovery earlier this month of a sinkhole in the ground and two empty pockets underneath that area.

It is possible that the formations were the result of ongoing underground tunnel construction to make way for an extended section of subway line No. 9, the Seoul Metropolitan Government said, while stressing that experts investigating the cause will soon provide a conclusive report.

The newly found empty spaces are smaller than the previous ones, one of which was 80 meters (262 feet) long. One of the pockets announced yesterday measured 5.5 meters long and 5.5 meters wide, with a depth of 3.4 meters. Another pocket was determined to be 13 meters long, 4.3 meters wide and 2.3 meters deep, according to the city government.

The size of the remaining three has yet to be determined.

Such pockets have the potential to weaken the ground, posing a threat to drivers on the road above.

The discovery came at a delicate time, when safety concerns are already heightened following the April 16 Sewol ferry disaster. After the sinkhole was found on Aug. 5, some pointed to the construction of the nearby Lotte World Tower complex. However, the municipal government said that the skyscraper is not directly linked to the hazardous geographic conditions. Seoul said it will hold the builder of the tunnel responsible if the investigation team finds that the construction is to blame in its final report.

Samsung C&T is in charge of the construction.

The city government is currently controlling the traffic on and near the site.

BY PARK eun-jee [ejpark@joongang.co.kr]