Demo, hold the dust

Safer, smarter practices in demolition

Sometimes, before a new building can go up, an old one must tumble down. Whether it’s fallen into disrepair and been deemed unsafe, or a new development can’t feasibly incorporate the old, some structures end up on the wrong end of a wrecking ball.

But modern demolition entails more than just smashing things or blowing them up. Complicated layouts such as aging power plants and bridges present unique challenges. Asbestos or other hazards might well lurk. And to be green, reusing and recycling are de rigueur. Let’s explore a new wave of innovation in the art and science of deliberate destruction. 

Hats off for the hat method

Three rival Japanese firms manage to demolish high-rises without smashing or blowing up anything at all. Across the nation, hundreds of towers more than 100 meters (328 feet) tall were erected four or five decades ago. Most aren’t up to the nation’s current, more stringent earthquake codes. That means a big demand is nigh for efficient, environmentally responsible demolition that doesn’t disturb the neighbors. (In densely-built Tokyo, as in many cities, there’s hardly even room to swing a wrecking ball today.) To meet that demand, the Taisei, Takenaka, and Kajima corporations are in a race to perfect a technique whereby a building is dismantled floor by floor.

In the Taisei and Takenaka systems, a protective “hat” or “capping” hangs from a high-rise’s roof. Covering the top three floors, this suspended scaffolding is covered with dust and noise barriers. Inside, crews cut holes in the floors and install temporary columns and giant hydraulic jacks. Then with jackhammers and excavators, they break apart the floors and walls. A ceiling traveling crane brings the refuse to an opening where a telpher crane lowers it to the ground floor. There, workers load the broken-up concrete and steel onto trucks that ferry it to a recycling center.

An illustration of the Taisei Ecological Reproduction System. To truly geek out on this, see the sequential diagrams in this slide show. (Source: Taisei Corp.)

Once a floor is demolished, the jacks lower the capping, and the cycle repeats. In this way, Taisei shrunk the 139-meter (456 feet) Old Grand Prince Hotel Akasaka by two floors every 10 days.

That project was covered by Wired and other American outlets. However, the Italian engineering firm Despe has been taking down buildings in a similar manner for years. They call their method Topdownway:

Taisei takes the method further by using a telpher crane that actually generates electricity. Though the crane itself uses electrical power, the motion of the crane dropping and rising creates energy that is captured and stored in a battery. The new energy powers lights and fans inside the capping.

Kajima’s demolition method is similar, using giant hydraulic jacks to shrink a building, but they dismantle from the bottom. The Kajima Cut and Take Down Method takes inspiration from a Jenga-like traditional Japanese game, Daruma Otoshi. See the time-lapse video of a Kajima project:

Cons and pros of these seemingly painstaking methods? It takes months to deconstruct a building, and it isn’t cheap. But Taisei estimates it reduces carbon emissions by 85 percent, noise levels by 20 decibels, and dust by 90 percent. Despe says its system contains 100 percent of the dust. Plus, the Italian company provides clients with advertising space on its highly visible protective tent.

Work in the enclosed space is not subject to the whims of weather. And best of all is the safety benefit. Whether inside the “hat” or operating from the ground floor, there’s no danger of debris or equipment falling on workers or passing pedestrians.

When failure begets success

Even the more dramatic form of demolition—using explosives to effect a controlled implosion—can be done in a smarter, more efficient way. A new entity in the UK offers a streamlined, tech-enhanced process, using robotics as well as explosives honed in the military.

The Atom Project comprises three firms that came together in the wake of tragedy. In February 2016, the conventionally planned demolition of the UK’s Didcot Power Station went awry when the building partially collapsed, killing four workers. For months, it wasn’t even safe to enter the teetering ruin to retrieve the workers’ bodies.

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An AR demolition robot at work.

The power plant owners fired the previous demolition contractor and brought in Arcadis, AR Demolition and Alford Technologies to collaborate on a solution. Pooling their experience, they used point cloud laser surveys to assemble a 3D model of the site to plan the number, placement, and strength of explosives. Top-of-the-line Kiesel demolition robots—capable of switching attachments in minutes—rolled in to cut and remove anything that could be salvaged.

The robots then placed linear cutting charges in the planned locations. These are explosives engineered to blast a knife-like cut into steel or concrete. They’re common in the military, but not yet in commercial demolition. “There’s a reticence about adopting the technology,” Alford Technologies Managing Director Roland Alford told the Construction News, “but it is totally reliable.”

The effort succeeded in bringing down the rest of the power plant—entirely remotely. The three companies decided to continue their partnership. Alford declared, “This is the iPhone moment for demolition,” a potential sea change in the way demo is done.

Rise of the “robots’” relevance

Of course, demolition robots themselves are not new. Swedish-based Brokk sold its first such vehicle in 1976. But their use is growing, for safety and cost reasons. Although they’re not, strictly speaking, robots.

“‘Demolition robots’ is the generally accepted term,” said Peter Bigwood, VP of sales and marketing for Brokk’s North American division. “It sounds cooler and trips off the tongue better than the more accurate nomenclature, which would be ‘remote-controlled demolition machines.’”

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Precision cutting with a Brokk machine.

Human technicians operate electric-powered Brokk and similar machines from a safe distance—as much as 100 yards away if need be. At trade shows, Bigwood will ask potential customers, “And would you like Brokk binoculars with that?”

Bigwood says several factors explain why his company is selling more Brokks than ever before—even with new competition from Husqvarna, suggesting “the pie is bigger,” he said.

“It’s really hard to get labor in construction,” Bigwood said. “There are parts of the country where you won’t find a guy who’ll operate a jackhammer.” Those who will are aging. “The spirit is willing, but the flesh is weak. They hurt their back or shoulders,” and that leads to expensive workman’s compensation claims. “If a robot costs 150 grand, that might be cheaper than a couple shoulder operations.”

Added to that, Bigwood said, is “a greater emphasis in the industry on safety, which as a human being I welcome wholeheartedly.” Hammering from afar using a remote control box means “keeping your workforce safe so they can go home at night.”

Demolish smart

Oftentimes, smart demolition is simply a matter of smarter planning. Derrick Chery, project manager on a Suffolk job in East Boston, worked with JDC Demolition to demolish a smokestack. Before imploding it, the team calculated the radius of the area that would be filled with smoke and dust; they then flooded the area to drastically reduce the dust.

“It’s not common to do a takedown that way, but it saved us a lot of time,” Chery said. “A few mini-excavators picked up all the brick and it took us only a couple hours to get it cleaned up,” versus the delays in a dust cloud scenario.

ENR recently reported on an innovative approach to a complex project, the dismantling of an abandoned sugar factory in Colorado. The team there used careful planning and asbestos-proofed trucks in order to defer the asbestos abatement to an outside facility.

And for complexity, you can’t beat the San Francisco–Oakland Bay Bridge. In three sections—two suspension bridges and a cantilever bridge—this 1930s structure stretched four and a half miles across the bay. With the opening of a new and more quake-resistant Bay Bridge, the old bridge has been under deconstruction since March 2015. The gargantuan effort includes cutting, imploding, and shipping away trusses on barges. Essentially, crews are taking the bridge apart in the reverse order of how it was built.

What happens to the materials?

Many in the Bay Area have wondered, what’s to become of the 167,100 tons of steel that made up the Bay Bridge? Most of it will be sheared to size and reused in construction projects across the country.

But much of the steel has been set aside for public art. For example, AECOM—an architectural firm that has been a frequent collaborator with Suffolk—will turn some of the salvaged steel into stylized benches and planters along a new river walk called Clipper Cove Promenade. Pedestrians will be able to stop and relax on pieces of the old bridge as they take in views of the new.

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A rendering of AECOM’s Clipper Cove Promenade. (Rendering courtesy of Oakland Museum of California)

Recycling can happen on a smaller scale, too. A Suffolk project team in southern Florida found 16 pallets of unused paint in a site slated for demolition. “It’s amazing that much paint was sitting around,” said Suffolk Senior Virtual Design & Construction Manager Kyle Goebel.

Rather than pay for disposal (or worse, cart it off to a landfill), Goebel arranged to donate the paint—all $25,000 worth—to the local Habitat for Humanity. Soon Habitat’s volunteers will be painting the walls of affordable homes in the region. “The cost of living is always an issue here,” said Goebel. “The fact that we were able to salvage this material efficiently and for a good cause was a great use of resources.”

Crash, boom, bang

Of course, recycling, robots, giant jacks and noise barriers, and all these innovative demo methods do lack one thing: the satisfying punch of a wrecking ball or dynamite implosion. So in case you need to scratch that itch, we’ve put together this little montage. Enjoy!

This post was written by Suffolk Content Writer Patrick L. Kennedy. Video edited by Suffolk Content Marketing Manager Zachary Leighton. If you have questions, Patrick can be reached at PKennedy@suffolk.com. You can connect with him on LinkedIn here or follow him on Twitter at @PK_Build_SmartYou can reach Zach at ZLeighton@suffolk.com or connect with him on LinkedIn here.

A park or farm in the last place you’d look

Inventive designs cram bounties of vegetation into unexpected spaces

In dense and growing cities, plant life is at a premium. Urban planners know the benefits of a bit of botany. As San Francisco-based advocacy group Canopy explains, trees suck up carbon dioxide while they pump out oxygen, making our air cleaner. Trees’ leafy cover provide shade, while their roots mitigate flooding. Grassy parks visually break up our concrete streetscape with green space, and they promote community interaction and physical activity. All of this makes city living healthier than it would be otherwise.

But designers have to be pretty creative to pursue these goals in the midst of a development boom. That’s why around the world, architects are finding innovative ways to carve out some elbow room for greenery in the built environment.

green2Pictured above and at right, the Botanic Center in Brussels represents one such solution. The architect, Vincent Callebaut, has proposed dramatically sprucing up a 1977 concrete apartment block with the addition of 274 planter beds to the façade and a striking “Chrysalis” on the roof—a steel-and-glass observation pod filled with a variety of plants and topped with wind turbines and a solar panel array.

From Tapei to New York City, from structures that reach the sky to tunnels that run beneath our feet, here are a few other designs that feature flora in unlikely quarters.


Agora Garden

Another Callebaut creation, this twisting tower in Tapei topped out last November and is slated for completion next September. (Inhabitat has a very cool slideshow of Agora Garden under construction.) As you can see from the above rendering, every one of its 22 stories will be packed with tree- and shrub-laden balconies. And these aren’t simply aesthetic amenities. Callebaut intends for residents to have sufficient outdoor space to grow their own produce. He estimates the plants will absorb 130 tons of carbon dioxide a year. On top of that, the building will incorporate solar energy, rainwater recycling, composting and other measures to further limit its impact on the environment.

Low Line

The Lowline

You may have heard of New York’s High Line, a park running along a disused section of elevated rail tracks. The Lowline takes that idea underground. An abandoned trolley subway tunnel beneath the streets of the Lower East Side will serve as the site for the world’s first underground park. How will the park’s plants flourish? Solar irrigation. A network of mirrors brings sunlight through pipes down into the tunnel, where the sun, normally, wouldn’t shine. The development team built a proof-of-concept Lowline Lab that proved a popular attraction over the past year or so. That bodes well for the full Lowline, projected for completion in 2021.

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Pier 55

British starchitect Thomas Heatherwick designed this 2.4-acre park to be sited atop an artificial island in New York’s Hudson River. Alternately called Diller Island after its developer, Barry Diller, Pier 55 is slated for completion in 2019. A distinctive element of the island is its support system. Heatherwick designed it to lie upon hundreds of concrete columns rising out of the water to varying heights, for a rolling landscape effect, up to 62 feet. While traditional steel piles have already been driven into the bedrock in the center of the site, the mushroom-shaped columns about the perimeter will be hollow precast concrete piers, to be filled with concrete on site.

Although the Army Corps of Engineers signed off on the design, the project recently stalled in federal court. However, it has weathered several court challenges so far, and it has the support of the mayor, the governor, and neighborhood groups. In any case, the design suggests the possibilities opened up by building on water—a long tradition in coastal cities. (Stay tuned to this blog for more on artificial island construction.)

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Mashambas

Skyscrapers are typically found in cities. But the winners of the eVolo Magazine 2017 Skyscraper Competition, Polish architects Pawel Lipiński and Mateusz Frankowski, instead direct our attention to rural, sub-Saharan Africa, where more than 40 percent of people live in absolute poverty. (The United Nations defines absolute poverty as a condition in which people suffer from not only low income but also a lack of access to food, safe drinking water, shelter, and other resources.) To attack this problem, Lipiński and Frankowski imagine a farming and educational center in a temporary, modular high-rise that can be assembled, disassembled, and transported from one site in need to another.

The Polish team’s prize-winning concept, Mashambas (from a Swahili word meaning farmland) would feature a permanent farmer’s market on the ground floor, with elevated “fields” for farming on the floors above. The structure would also contain warehouses—for fertilizer, seeds, drones, and equipment—and classrooms. In the architects’ vision, staff would use those classrooms, as well as the farming modules, to train local subsistence farmers in modern agricultural practices. The farmers would then move on to growing crops in their own fields nearby. Eventually, the community would become self-sufficient, and the Mashambas tower could be dismantled and shipped to the next village, leaving behind the anchoring farmer’s market and one-story warehouses.

To be sure, a vertical farm might work at least as well in a cramped urban environment, but by siting their winning eVolo design in a developing rural region, Lipiński and Frankowski are raising awareness of the struggle farmers there face.

Mashambas interior

This post was written by Suffolk Construction’s Content Writer Patrick L. Kennedy, with additional research by Suffolk Intern Simone McLaren. If you have questions, Patrick can be reached at PKennedy@suffolk.com. You can connect with him on LinkedIn here or follow him on Twitter at @PK_Build_Smart.

Lowering the ceiling to raise the roof

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An artist’s rendering of the Golden State Warriors’ new arena in San Francisco. Rendering courtesy of MANICA Architecture.

As the NBA Finals come to a close this week with Golden State potentially winning its first title since 1975, we were impressed by Steph Curry and the Warriors once again blowing the lid off the infamously noisy, but dated, Oracle Arena in Oakland on Sunday night. We are equally impressed by the architects and engineers recreating that rock-concert atmosphere in Golden State’s gleaming new arena set to break ground in San Francisco this January.

With its low-slung ceilings and sound-reverberant concrete surfaces, Oracle is known to reach 120 decibels — that’s as loud as a jet engine!

An artist's rendering of a new park that would be planted at the foot of the Golden State Warriors new arena in San Francisco. Courtesy of MANICA Architecture.

An artist’s rendering of a new park that would be planted at the foot of the Golden State Warriors’ new arena in San Francisco. Rendering courtesy of MANICA Architecture.

New arenas often disappoint fans yearning for the old-school flavor of their former ballparks, especially when it comes to the noise factor since sound loses steam the further it travels through air. So harnessing that energy inside a sleek modern arena that lacks concrete and is designed to be more open is a tall task that falls to the Machete Group and MANICA Architecture, whose owner, David Manica, worked on O2 Arena and the new Wembley Stadium in London as well as Beijing’s Olympic Stadium.

Two major ways architects are recreating Oracle’s fan experience from an acoustic standpoint are by limiting the new arena to 18,000 seats and by featuring only one level of suites in an effort to keep the ceiling low and the sound off the charts.

“We are working with world-renowned acousticians, and state-of-the-art acoustic simulators, to ensure that the new arena is just as loud and exciting as Oracle is,” Manica told us.

Game 6 of the NBA Finals is at 9 p.m. EST on Tuesday night on ABC. For more on the Oracle and the Warriors’ new arena check out Sports Illustrated. For more on the science of sound in stadiums click here.