Cracks raise safety fears about Lotte World Tower
Eight core mega-columns, which will support most of the weight of the skyscraper, are now 17 floors high.
The problem is that 11 large cracks, easily seen by the naked eye, have developed on the columns on the 5th, 8th and 9th floors. An inspection of the building last October said construction should be stopped until the problems with the columns were straightened out.
The builder, Lotte Engineering and Construction Corporation, hired another inspection company that said everything was fine and construction should continue. It has. Some people think it’s a disaster in the making.
“The construction company should not add additional floors that will put more stress on those mega-columns until they find out the exact cause of the cracks,” said a foreign expert who participated in building Dubai’s Burj Khalifa, the world’s tallest building.
The Lotte World Tower, which is supposed to be completed by October 2015, will be the centerpiece of the second Lotte World amusement park, which is being built on 26,500 pyeong (21.6 acres) of land in Songpa District. The tower will house a six-star hotel. The new Lotte World will be connected by a tunnel to the original amusement park across the street.
The project has been embroiled in controversy for decades. In 1995, the Lotte Group submitted a plan to the Seoul Metropolitan Government to build a 100-story building (402 meters tall). The Korean Air Force opposed it because Seoul Air Base in Seongnam in Gyeonggi is close, and a building that size would affect landings and takeoffs. It said that the maximum height of the building shouldn’t exceed 164.5 meters. During the presidential terms of Kim Dae-jung and Roh Moo-hyun, Lotte submitted a revised plan for an even taller 555-meter tower, which was shot down by the Ministry of National Defense for the same reason.
In April 2008, President Lee Myung-bak, whose campaign pledges included improving the country’s economy, ordered the Defense Ministry to cooperate on the project, and the project was eventually approved by the government in 2010.
Last year, Hanmi Global, a construction inspection company, was hired to inspect the site. On Oct. 25, it wrote in a report, “Serious cracks were found on concrete that was welded with steel frames on a mega-column on the 9th floor. Additional welding works for other columns should not be allowed until architects and construction supervisors find new welding methods for columns.” The report mentioned other cracks as well.
The report made several demands of the construction company, which is part of the Lotte Group: to conduct a precision safety diagnosis with an external company that specializes in building safety inspections; to provide new welding techniques for the columns; and to provide a repair plan for the damaged columns.
In December, about 40 days after it received the inspection report, Lotte E&C hired a company specializing in building safety inspection and asked them to check the columns. After only three days, it submitted a written opinion saying there was no safety problems in the tower.
But that company says its report wasn’t definitive.
“We judged that they can continue working on the tower but we only checked those cracks with our naked eyes,” an official of the inspection company said. “Lotte E&C asked us to give our opinions regarding the safety issue in writing, but didn’t ask us to run tests that could find the causes of those cracks on the columns.”
After the news was reported by the JoongAng Ilbo, the Seoul Metropolitan Government, which is in charge of supervising construction operations in the city, dispatched three specialists to the site yesterday.
“We will make a judgment whether we will order a stop to the construction on the Lotte World Tower after conducting a thorough inspection,” Kang Maeng-hoon, director of the Housing and Architecture Policy Division, told the JoongAng Ilbo. “We also ordered Lotte E&C to consult with foreign professors and construction experts.”
“If it is true that Lotte E&C continued construction despite Hanmi Global’s request to stop, it means that the builder isn’t listening to what its consultant is saying,” said an executive who worked on the construction of Taiwan’s Taipei 101, a 509-meter tower. “The problem is that the companies who ordered this construction project and those in charge of CM [construction management] are all affiliates of Lotte Group.”
According to Park Youg-in, director of the second Lotte World Project: “We strongly believe that there could be some problems when workers welded concrete with steel frames, but the concrete we used in the columns do not have any problems. We could not stop the construction process because of some cracks. But we will run a thorough inspection as requested by the city government.”
By Moon Byung-joo, Yoon Ho-jin [firstname.lastname@example.org]