Earlier this year, the Council on Tall Buildings and Urban Habitat (CTBUH) revealed that 106 buildings – 200m or taller – were completed in 2015 around the world. CTBUH’s 2015 Year in Review report said 13 ‘supertalls’ – buildings 300m or higher – were completed during the year, making it the highest annual total on record. Neha Bhatia investigates.
CTBUH’s list was dominated by Chinese cities, where 62 tall buildings were built in 2015. However, the Middle East’s presence is also marked on the list by cities like Dubai and Abu Dhabi.
The UAE follows China and Indonesia with the highest number of towers completed in 2015. Including towers in Dubai, Abu Dhabi, Manama, and Jeddah, the Middle East had nine completions last year, marking the first time since 2009 that the region had fewer than 10 entries of towers 200m or taller in a year, CTBUH said.
“As one might expect from the region’s most popular commerce and tourism destination, Dubai led the pack with four completions, while Abu Dhabi closed the year with three,” CTBUH’s report continued, adding that Dubai’s under-construction Marina 101 and The Address BLVD are expected to be amongst 2016’s top 10 tallest towers.
To say the Gulf has a soft spot for tall buildings would be an understatement. The region is home to both the tallest existing manmade structure in the world, the UAE’s Burj Khalifa, and the soon-to-be-tallest structure, Jeddah Tower.
Emaar’s recently launched tower at Dubai Creek Harbour, meanwhile, will cost $1bn (AED3.67bn). The building, which the developer says will be “a notch taller than Burj Khalifa”, will rival Kingdom Holding’s Jeddah Tower. CNN reported in 2014 that the latter will cost an estimated $1.23bn (SAR4.6bn) – and in the current economic climate of stagnant oil prices, that figure could climb.
But the obstacles faced by high-rise builders in the GCC extend beyond the financial, as Ahmed Osman, DeSimone Consulting Engineers’ managing principal, tells Construction Week. “GCC projects have the tendency to be more complicated – the structural engineering more challenging – than in other parts of the world, due to reasons both obvious and hidden,” he explains.
“Firstly, architects have more freedom to express their ideas and focus on striking designs. This is encouraged in order to win the hearts of owners and overcome their rivals, which consequently challenges the structural engineering design.
“[Hidden reasons include] strict rules and regulations relating to the number of car parks stipulated for every project, which leads to risky, deep excavations,” Osman continues.
“Engineers and contractors must design and build their structures carefully to avoid any catastrophic failures to their sites, and neighbouring sites as well. The harsh environment that attacks the structures – represented in chemicals found in soil; salty water attacking foundation elements; and high humidity and sand particles in the air – also have to be considered when designing the skins of tower projects.”
Varying soil structures represent a key consideration for GCC builders, especially for towers with deep foundations. Shad Khan, business development director at Keller Grundbau Middle East, tells Construction Week that soil composition may vary across different parts of a country. Experience, therefore, is a crucial element when designing deep foundations.