The long and short of skyscrapers today
Technology and innovative approaches to engineering solutions allow for the construction of tall buildings quicker than ever before. It took about seven years to build the Burj Khalifa, an 830m high skyscraper in Dubai, United Arab Emirates. ‘I was the chief engineer on this project. One of the challenges we encountered was the need to find quicker ways to build tall buildings’, says Davids, Aurecon’s buildings director for the Middle East and North Africa
Developers and clients can’t always wait years for a project to be completed, so engineers have come up with a holistic construction system for building a tall building in half the time it used to take.
Being able to cut the construction time of a building as tall as the Burj Khalifa in half,or by a third, is a significant achievement. Since that project, I have been involved in the design of many megastructures constructed within mere months.
Modular systems help us construct tall buildings more quickly. But some existing 400m and 500m tall buildings are individually handcrafted and they are each unique and beautiful.
There’s a beautiful hotel in China called the T30 Hotel. It was prefabricated and the 30-storey tower was erected by 200 Chinese workers in just 15 days, breaking the Broad Group construction company’s record of building a 15-storey building in just one week.
This was possible because modular, prefabricated solutions were used. These principles are being extrapolated to expedite the construction of even taller buildings. The goal isn’t to break records, but to deliver high-performing, tall buildings within a shorter time.
The modular systems being used in tall buildings are primarily floor systems and columns. The floor system is pre-engineered and pre-built, so the floor decking and beams are already in place when construction workers start erecting a building. The columns are also pre-engineered and brought to site in a cleverly orchestrated way so that cranes lift them into place in a relatively short time.
WITH the Shanghai Tower project, the developer wanted a clever product to build the tower instead of simply designing the building as a one-off project. This led to a focus on creating a modular solution that could be replicated to build additional tall buildings at a quicker speed.
This doesn’t mean that every building is going to look the same or perform in the same way, but it gives engineers the ability to offer mass customisation to countries, cities and developers who need tall buildings within a shorter time frame than we were able to deliver in the past.
The mass production of modules that can be customised according to the needs of each individual client is now a popular means of construction.
Buildings are not only becoming taller, they’re becoming more majestic and able to perform better in terms of energy efficiency and indoor comfort levels for its occupants. Besides being more aesthetically pleasing, they’re also becoming more economical and easier to construct.
Design professionals, specifically architects, feel they are less constrained by technology than in the past — and rightfully so. As consulting engineers, it’s our job to use our technical skills so that an architect or a client’s vision can be realised.
Today, we’re able to build magnificently intricate tall buildings that tell a story thanks to the customised, handcrafted ideas of architects, which leads them to dream and plan bigger. In turn, the pressure is put on engineers to find workable building solutions to bring their visions to life.
Our ability to create extraordinary projects can be attributed to the collaboration between design teams and our willingness to cross traditional boundaries.
Whether it’s unique geometric shapes, complex facades or extreme wind testing and analysis that needs to be done, the engineers on a project need to come up with a workable solution.
Many of the existing tall buildings are upmarket, residential buildings or luxury hotels and most people won’t have an opportunity to live that way. The current and planned tall buildings, however, address a very real and important issue that many countries and cities face — they are running out of space to house people. This is a key driver of many planned projects.
In China, for example, a single square kilometre houses about 50,000 people. These people typically live in three-to four-storey buildings that cover approximately 50% of the land area. After the infrastructure for roads has been laid, another 20% of the land space is accounted for. This leaves about 30% of the area for recreation, growing food, energy production and other activities. This is a serious problem because certain areas in China will eventually run out of land. So tall buildings not only address sustainability issues, but in many cases, a problem that could mean life or death to large segments of the population. Instead of looking at marginalisation and equality, tall buildings become part of a life and death argument.
If, for example, we can house the same 50,000 people on 10% of the land space because of tall buildings, we are left with 90% of the area for recreation, food production, energy generation and infrastructure — an incredible improvement on the current situation.
• Davids is Aurecon’s buildings director for the Middle East and North Africa.