BuiltWorlds kicks off its exciting 2020 calendar with our Buildings Conference in March. Over two days in Chicago, we'll examine the innovations in building materials, technologies, and techniques. The conference will also include case studies focused on the development of high-performance structures and"smart buildings," and how these projects are actually built. Earlier this year, we wrote about the innovations that are allowing builders to continue constructing taller and taller skyscrapers. The article features thought-leaders discussing how they are conquering the next wave of supertall buildings.
Humans are always looking for hurdles to overcome, challenges to conquer. We are always building better, taller, faster things. This is especially true in the construction industry. Ever since we began constructing shelters and living spaces, humans have been trying to reach the sky with increasingly taller and taller buildings.
Today, as you read this, we are once again getting a little closer to the sky with a new boundary-pushing project. The Jeddah Tower (also known as the Kingdom Tower) is currently under construction in Saudi Arabia and set to be completed next year. Rising to a startling--and sweat-inducing--3,280 feet, this project is only the latest example of our desire to build the next best thing and reach the next rung above us.
As impressive a feat as the Jeddah Tower will be when it’s completed, one day we’ll be talking about the NEXT highest building that will tower even this 1,000-meter project. In order for that inevitable next step, there are some technical and mechanical innovations that need to happen. The Jeddah Tower is pushing the boundaries of many of the systems that help super-tall buildings stay safe and structurally sound. With that in mind, here are three critical systems that are enabling the on-going construction of the Jeddah Tower, and will make the next super-tall building a reality:
1. MEP Systems
Every building needs mechanical, electrical, and plumbing systems. But with a massive project like the Jeddah Tower, the planning and installation of these systems is a gargantuan undertaking.
“Projects of this type are really integrated and call for a very interdisciplinary type of process with a large team,” said Mehdi Jalayerian, Managing Director of ESD and the principal in charge the Jeddah Tower’s MEP systems. “I always describe these mega-tall buildings as vertical cities.”
The ESD team oversaw a huge swath of the building’s essential systems, including the heat and cooling, ventilation, power, lighting, emergency power, safety systems, water supply and distribution, water drainage, and fire protection.
The sheer height of the tower provided Jalayerian and his team with some problems. With the water distribution system, the tower’s height creates pressure on the piping system because of the vertical pressure. Additionally, the temperature of the building also required the team to innovate.
“As you go up in elevation, the outdoor temperatures change,” Jalayerian said. “So we needed to create those design parameters that are not really done in the industry.”
Jalayerian also stressed the need for integration and teamwork with the other teams working on the Jeddah Tower. For example, ESD worked with the building’s architects to coordinate the installation of about 19,000 holes in structural beams, columns, and sheer walls for ducts and piping.
Moving forward, before building the next tallest skyscraper, Jalayerian believes a few advances need to happen before we get any higher than the Jeddah Tower.
“The building cannot be taller unless we take the next generation of technology and come up with different ideas,” he said.
Because of the pressure at such a dizzying height, the MEP systems cannot function at much higher pressures. It’s something that will need to be addressed before the next tallest building breaks ground.
2. Elevator Systems
In such a tall building like the Jeddah Tower, elevators play a crucial role. This requires the development of a complicated elevator system that transports residents, tenants, and visitors safely, quickly, and effectively.
KONE oversaw the installation of all vertical transportation systems in the Jeddah Tower. Much the MEP systems, it was a huge and crucial undertaking.
“Our main goal is to try and ensure that elevators are assistive in getting people where they want to in the least obstructive way possible,” said Steve Gonzalez, KONE’s Director of Major Unit, America.
In most super-tall buildings, it is necessary to install “sky lobbies”--places where riders have to switch elevators to reach higher floors--on various floors, because elevator systems have limits who how far they can reach. But in the Jeddah Tower, KONE was able to decrease the number of sky lobbies using its state-of-the-art hoist and rope system, UltraRope, which weighs only 10 percent of a normal traditional steel elevator cable.
UltraRope allows for an elevator to climb from the base of the Jeddah Tower to the observation deck in a single trip, amounting to a stunning 653-meter journey.
“There is no elevator that has a single journey as long as this one,” Gonzalez said. “It is the longest travel of any elevator system in the world.”
Moving forward, technology like UltraRope will allow elevators to climb higher, and decrease the need for sky lobbies. Gonzalez says that during the next iteration, KONE needs to figure out ways to move people that high and fast, while also making sure they are safe and healthy. Changes in pressure and temperature come into play when you are traveling at such heights.
“We’ve solved the mechanical part of the problem,” he said. “Now it’s a matter of how fast can humans go from ground level to 700 meters above ground.”
Have you ever been in a skyscraper that noticeably swayed back and forth and vibrated? It’s a particularly unsettling sensation.
“People don’t like being accelerated back and forth,” said Elisabeth Malsch, Ph.D., PE, Senior Principal at Thornton Tomasetti, which provided the structural designs for the Jeddah Tower.
“They get seasick and afraid at certain levels of vibration.”
That’s why most super-tall buildings are designed with damping systems, which dissipate the energy exerted on a building and keep the structure from vibrating.
“Buildings are built for people and we want to keep them from getting seasick or afraid,” Malsch said.
What’s interesting about Jeddah Tower is that it doesn’t have traditional supplemental damping, which is when damping measures are applied throughout the building. This is because the tower has a wide aspect ratio (its base is large), and it is constructed from concrete, which is less susceptible to kinetic energy.
“The combination of material and engineering design of the aspect ratio is the reason why it doesn’t have supplemental damping for the main body of the building,” Malsch said.
When talking about the next largest super-tall building, Malsch said theoretically, as long as the base of the building is wide enough, like the Jeddah Tower, supplemental damping isn’t necessarily needed.
“As long as you can make a building as wide as you need, you could already build it as tall as Jeddah tower--or taller--without necessarily needing supplemental damping,” she said.
Where things get more complicated is when it comes to building skyscrapers in cities, which don’t necessarily afford the luxury of constructing a large base.
“As buildings get taller--and especially as they get thinner--the sensitivity of the building to vibration increases,” Malsch said.
This is where advances in supplemental damping will certainly come in handy, especially systems that compact the damping system into a small amount of space. Currently, there are several innovations in supplemental damping that will allow a tall, skinny, steel-constructed skyscraper to be built taller than Jeddah Tower. One interesting example is the Hummingbird Kinetics Damping System, which Malsch helped develop. This system uses conventional piping in building to harness water throughout the building, which greatly assists in the damping process.