Mysterious Sinkholes Could Slow Construction of Korea’s Tallest Skyscraper

by TONY KIM

The emergence of multiple sinkholes throughout Seoul, including ones along the streets where the Lotte World Tower is being built, has raised public concern about the safety and soundness of the construction of Korea’s tallest building-to-be.

Officials from the Lotte Group didn’t seem to have an explanation for the mysterious depressions, one of which measures half a meter wide and 20 centimeters deep, and was found about 500 meters from the construction site, according to AP.

“We are working on an investigation of sinkholes, but it will take some time to figure out what’s going on,” Seulki Lee, a spokesperson for the Lotte Group, told CNN.

Lee said that Lotte engineers believe that the tower’s construction is unrelated to the appearance of the sinkholes, but that’s hardly a comfort to the public.

After pictures of the sinkholes started circulating via social media, and especially in light of the Sewol disaster that raised concern over public safety in Korea, government officials are responding to the problem with caution—a response that threatens to stall the construction project. More than half of the floors of the 123-story, 1,824-feet-high tower have already been constructed. Once finished, in 2016, the Lotte tower–to house a hotel, office space and apartments—will be the sixth tallest building in the world.

But Seoul government officials appear to be prioritizing the safety issue, even over the progress of such a large-scale development. Last month, in an unusual step, the Seoul government formed an advisory committee made up of engineers, scholars, attorneys, architects and environmentalists and asked them to submit their opinions about the Lotte tower project, AP reported. The city even rejected Lotte’s request to open a shopping mall that is part of the development, noting that safety and traffic issues needed to be addressed first.

“After Sewol, the public’s sentiment has taken a turn to stress safety over any other values including economic development,” engineering professor Park Chang-kun, who sits on the tower’s advisory committee, told AP.

Further adding suspicion around the Lotte project is the fact that water levels in a nearby lake fell from 16.5 feet to 14 feet, according to various media reports. Park told AP that, while touring the Lotte construction, he saw water pooling in the sixth basement of the building and said that it could very well be from the lake. He said that “water circulation underground could have accelerated due to the construction.”

There are several possible causes of sinkholes, including water that might be dissolving land covered by limestone or gypsum; surface drainage or erosion; and construction, which can indirectly cause the holes by diverting groundwater pumping.

In the past five years,  133 sinkholes have appeared in Seoul, according to Arirang TV.

Photo via the Korea Times