High-Rise Concerns

Super-tall buildings reach for the skies but problems remain on the ground By Yin Pumin

High-Rise Concerns

Super-tall buildings reach for the skies but problems remain on the ground By Yin Pumin

RACING TO THE SKY:A man points to the Shanghai Tower (front)under construction alongside the Jin Mao Tower and Shanghai World Financial Center in Shanghai on January 17

Authorities in Wuhan, capital of central China’s Hubei Province, are mulling whether to add height to a building project, in order to construct what would be the tallest building in China upon its completion.

The Wuhan-based contractor Greenland Construction Group announced the possible change in the building’s height on February 27.

“The Wuhan Municipal Government initiated the adjustment plan in order to bring about a landmark building,” said Lu Zhenxing, the company’s marketing director.

The Wuhan Greenland Center, being built in the downtown Wuchang area of Wuhan,was originally designed to rise approximately 606 meters and have 119 stories above ground and six beneath, with a total floor area of around 300,000 square meters and an investment of 5 billion yuan ($791 million). Based on initial plans, the skyscraper, which is expected to contain luxury hotel suites, office space, high-end stores and apartments, would have been the second-tallest building in China upon its completion in 2017.

The adjustment will require its height to surpass that of the 632-meter Shanghai Tower,which is under construction and currently scheduled to become China’s tallest building.

The Wuhan Greenland Center broke ground in 2011 and work is still being done on its foundation pit. The building is part of a planned commercial compound that will cover 3 million square meters and cost about 30 billion yuan ($4.74 billion).

Xiao De, a professor at the School of Business of the Wuhan-based Hubei University,said he was not surprised by the height adjustment plans. “Along with the constant development of China’s economy, it has become a common phenomenon in Chinese cities to compete for having the ‘tallest building,’ in order to show wealth or boost their international recognition,” Xiao said.

In Wuhan alone, three buildings taller than 600 meters were proposed in the past year—the 606-meter Greenland Center, a 666-meter high-rise in Hanzhengjie Market and a 707-meter skyscraper along the Yangtze River in Jiang’an District.

In Beijing, construction work on a 108-story building, called China Zun, began with a groundbreaking ceremony in the city’s central business district (CBD) last September.Shaped like an ancient Chinese wine vessel,the 500-meter-high skyscraper will be the capital’s tallest building, dwar fi ng the nearby China World Trade Center Tower 3, which at 330 meters is the tallest building in the city.

According to a report, entitled 2011 Skyscraper City Rankings of China, released by the Shanghai-basedSkyscrapersmagazine in June 2011, the total number of skyscrapers under construction in China had exceeded 200, equal to the total number of skyscrapers in the United States. Hong Kong had the most skyscrapers of any Chinese city with 58, followed by Shanghai with 51 and Shenzhen, a boomtown in southern Guangdong Province, with 46.

Skyscrapers are defined in the report as buildings of more than 500 feet, or 152.4 meters, in height.

A new skyscraper is built every fi ve days in China and by 2016 the total number of skyscrapers in the country is expected to exceed 800, says the report.

Currently, seven of the world’s 10 tallest buildings are in China.

Vanity projects?

Given the overall size of China’s economy,the report raises doubts over whether the country needs so many skyscrapers.

TheSkyscraperreport also suggests that China might be over-investing in skyscrapers.

The biggest concern is that some cities with limited fi nancial resources have also announced plans to build expensive skyscrapers.

Take Guiyang, capital of southwestern Guizhou Province, for example. It was ranked fi fth in terms of the number of high-rise buildings under construction, according to the report. The city planned to build 17 skyscrapers. Its GDP,however, only recently breached the 100-billionyuan ($15.82-billion) mark, too low to sustain the construction of so many skyscrapers.

Wang Jianmao, an economics professor at the Shanghai-based China-Europe International Business School, said that skyscraper construction, initially seen as a way of improving land ef fi ciency, has resulted in too many vanity projects in

China.

“C h i n a d o e s indeed need tall buildings in the process of urbanization because the country has a large population.Skyscrapers could, to a degree, help reduce land consumption,”Wang said. “However,given the high costs of building skyscrapers and maintaining them as well as the environmental problems they cause, urban planning authorities should be cautious in approving skyscraper projects.”

The 421-metertall Jin Mao Tower,Shanghai’s second tallest building, cost 20,000 yuan ($3,163)per square meter to build in 1994-99.However, the building costs more than 1 million yuan ($157,480)per day to maintain according to the Shanghai-based news portal Eastday.com.

A new skyscraper is built every five days in China and by 2016 the total number of skyscrapers in the country is expected to exceed 800

Safety hazards

The skyscraper boom in China has also raised concerns over the safety of the buildings.

Li Zhengnong, a professor at the Civil Engineering School of Hunan University, said that high-rise buildings are susceptible to safety problems, since disasters in such buildings, especially fi res, are dif fi cult to cope with.

However, skyscraper developers in China seldom pay attention to such issues. For example, regulations stipulate that there should be an emergency fire refuge for every 14 fl oors of a building, but many skyscrapers in China do not meet that standard.

According to the Fire Service of the Beijing Municipal Public Security Bureau, safety concerns remain over the fi re fi ghting facilities included in the designs of the China Zun in Beijing.

LUO XIAOGUANG

Ma Jianmin, director of the service’s building plan review section, said, “Although the most advanced fire lifts will be installed in the skyscraper, they won’t be of any use once a fi re paralyzes the power system.”

The building’s top floor will function as a sightseeing platform and café, providing visitors with a panoramic view of the CBD,according to the developer CITIC Group.

This, however, raises more safety concerns.It is stipulated in law that a parking apron as well as a refuge story should be incorporated into such tall buildings. The China Zun currently fails to meet these design standards.

“It will take two more years to improve the fi re fi ghting facilities in the building,” said Wu Chen, one of the main designers of the China Zun.

Another major problem associated with skyscrapers is land subsidence. According to a report from the national broadcaster CCTV in February, signs of land subsidence have been reported in more than 50 cities across China. Excessive exploitation of underground water is believed the main cause for the problem, but an increasing density of high-rise buildings in urban areas has also been blamed for causing land in cities to sink.

Early in January, the downtown Hailun Road Station of the Shanghai Metro Line 4 was closed for emergency reinforcement after the occurrence of “uneven subsidence.” Pit digging work for new buildings nearby caused the subsidence, according to theShanghai Daily.

Usually, “uneven subsidence” takes place where there is construction work, which adds considerable weight to the base and leads to cracks and distortion.

To tackle the problem in a more systematic way, the State Council, China’s cabinet, approved the Land Subsidence Prevention Program on February 20, demanding local governments to improve their management systems to ensure building stability and come up with more effective measures to prevent subsidence.

For the construction of skyscrapers, meticulous preparation is now required to ensure safer designs, and it is important to take possible earth slippage issues into consideration before construction in order to prevent problems caused by subsidence.