Another sinkhole plagues construction area
The sinkhole, which measures 0.6 meters wide and 2 meters long, was discovered on a sidewalk near Bangi Crossroads in Bangi-dong, Songpa District.
The district is where a number of sinkholes and underground air pockets have been found over the past month, which the Seoul Metropolitan Government attributes to construction efforts carving out an underground tunnel to make way for an extended section of subway line No. 9.
This month alone, a total of eight sinkholes and air pockets, including yesterday’s formation, were recorded in Songpa District.
While the latest sinkhole is 60 meters away from the subway construction site, the city government has yet to announce what caused it.
The discovery came at a sensitive time, when safety concerns are already magnified in the wake of the April 16 Sewol ferry disaster.
The threat of sinkhole and vacant pockets in subterranean areas has spread across the country. Large chasms have also been found in other regions, like Cheonan and Jeonju, as well as in Seoul.
Following a series of discoveries in Seoul, a sinkhole appeared in Cheonan, South Chungcheong, the Cheonan City Government said on Wednesday.
The hole, which was 2 meters long and 2 meters wide, with a depth of 10 meters, was found at Yeongseong Underpass last month in Seobuk District, prompting city officials to take emergency measures. The site is considered one of the busiest roads in the city.
Cheonan said that soil erosion and subsequent ground sinking caused by an old, dysfunctional sewage system were behind the formation of the pit.
Rural sinkholes typically open up when the ground is affected by erosion or exposed to water.
However, underground construction can hurt sewage systems and ground conditions in cities when it is not properly conducted.
In Jeonju, a sinkhole was also found in Pyeonghwa-dong, prompting officials to begin traffic control.
Seoul said it will hold the builder of the tunnel responsible if an investigation team finds that the construction is to blame in its final report.
Samsung C&T is in charge of the construction.
The construction company has employed a Shield Tunnel-Boring Machine (TBM) to excavate the ground.
A Shield TBM spins a cylindrical shield that grinds sand and rocks to excavate straight tunnels from underground. It is commonly used as an alternative to drilling.
Some experts say that such a method could weaken the ground or cause soil erosion.
A team of geologists and officials are currently working on releasing a conclusive report on the potentially harmful geological phenomena.
The Seoul Metropolitan Government said that the final report will be announced early next week.
BY PARK EUN-JEE [firstname.lastname@example.org]