More cracks on Lotte World Tower

중앙일보 2월 5일자 1면.

More cracks were found on columns that will support the 123-story Lotte World Tower in Jamsil, southern Seoul.

But the Architectural Institute of Korea, which has been conducting an inspection of the construction after previous cracks were spotted, said they aren’t a serious problem and can be fixed by the builder, Lotte Engineering and Construction Corporation.

Since the JoongAng Ilbo exclusively reported that it found 11 large cracks on eight so-called mega-columns, which will support most of the weight of the 555-meter (1,820 foot) skyscraper, the Seoul Metropolitan Government formed an inspection team composed with experts in architecture and construction engineering. It has been conducting a precision safety diagnosis since mid-February.

The Lotte World Tower will be the centerpiece of the second Lotte World amusement park and Korea’s tallest building when it is completed in October 2015.

The team described an interim report to the media yesterday at the office of the Architectural Institute of Korea in Seocho-dong, southern Seoul. It said it found dozens of small cracks on the mega-columns.

“There is no structural problem with those mega-columns,” Shin Sung-woo, director of the team and an architecture professor at Hanyang University, said. “But we found additional cracks and they need to be repaired along with the cracks that were found previously to secure the durability of the columns. If rainwater permeates into the cracks, it could rust the steel frames on the columns.”

The team said they have found a total of 98 cracks on mega-columns in 24 areas between the 4th and 10th floors.

“We recommend the builder, Lotte Engineering and Construction Corporation, use mortar on the surface of the cracks and inject epoxy,” Shin said. “We will find a better method for the builder.”

The team said it will conduct an experiment with a model of the tower to prevent cracks developing in the columns.

By Yoon Ho-jin, Kwon Sang-soo [sakwon80@joongang.co.kr]