The bright and eclectic landscape of downtown Miami is changing – thanks to the addition of a bold and innovative residential tower from world-renowned architect Zaha Hadid. The first of her architectural celebrations in the Western Hemisphere, One Thousand Museum by Zaha Hadid Architects will be a cutting-edge, contemporary, luxury residential tower that will rise more than 62 storeys high to encompass a total of 83 residences in 30,000 square feet.
Hadid’s signature curves are evident in the design, which uses fluidity throughout to combine the building’s exoskeleton with a recessed glass façade. The result is an ambitious and striking landmark tower that will rightfully earn its place on Miami’s rich architectural scene.
It is also one that has put the requisite pilings work to the test.
The complex design of One Thousand Museum is one that calls for an extra deep foundation to provide the necessary structural support for the towering structure that will rise above ground.
“This was an urban in-fill project in Miami, one of the last sites available in the downtown boulevard,” states Kevin Venger, developer for One Thousand Museum. “This is the missing piece to the luxury condos on that boulevard.”
Venger describes Hadid’s designs as using a “geometric curvature” to create buildings that “flow” from a structural standpoint.
“We’re rising 700 feet above the ground but to do that, we need to go 155 feet below the ground to put in the support piles,” explains Venger, who opted to use Miami-based HJ Foundations for the installation of augercast piles. “HJ Foundations has perfected the auger drill shaft. They installed 242 piles with 30-inch diameters in 85 working days. That’s unheard of and would have taken us twice the amount of time and double the cost if we were to have done it with traditional caisson piles.”
According to Frank Fonseca, president, HJ Foundation, a Keller Company, the company’s “mega piles” (as he refers to them) are the result of 10 years of development in perfecting the craft. It’s one that carries over the efficiencies earned on smaller buildings to taller ones – one that Fonseca describes as having occurred over the course of several years.
“Traditional caisson piles could have been used on this project but it would have been more expensive and time consuming to install,” he says. “Because of our market share, we have used mega piles in hundreds of buildings in Miami over the years. We have perfected the design and implementation of augercast piles in high-rise towers like this one.”
HJ Foundations designs its own proprietary equipment and is able to meet the needs of different developers as a result.
“Our equipment is the biggest and most powerful in North America,” he says. “It is custom built to our specifications.”
The company is capable of installing piles as large as 42 inches in diameter and as deep as 170 feet, with load capacities as great as 1,800 tonnes per pile.
In the case of One Thousand Museum, HJ Foundations used 30-inch diametre augercast piles and went as deep as 160 feet on most of them. There were, however, a few exceptions to the rule.
“We broke the world record by going 177 feet deep on this job with a few of the piles,” says Fonseca.
The soil conditions were typical of south Miami and posed no significant challenges for the experienced crew.
“The soil is intermittent layers of sand and limestone,” explains Fonseca. “We sometimes hit voids in the limestone formations but we just filled them in and kept going. In all, the project progressed pretty much as we thought it would, thanks to a lot of foresight and planning.”
Venger adds that every pile installed took about five truckloads of grout. “It required a lot of careful timing and sequencing,” he says. “But we never had to abandon a pile. At the worst, we had to go back and refill.”
According to Fonseca, the work below the ground at One Thousand Museum went relatively smoothly.
“We try to break down complex projects that developers create above the earth and make them uniform below the ground,” he explains. “Although the piles in this case were deeper than most, the rest of the job was fairly typical. Our work tends to go unnoticed because it does take place underground. Now that we’re done, the sexy part of building above ground can begin.”
“We used almost 10,000 yards of concrete for the foundation,” says Venger, who adds that it took about 1,000 truckloads of concrete to complete the 24-hour pour. “We used seven different batch plans and had 170 trucks cycling at any given time. We had 25 off-duty police officers on hand to direct the traffic. We had five pumps per truck and had 10 trucks pumping continuously.”
Given all the activity that the foundation pour entailed, it surprisingly went well.
“Getting the piling work and the foundation in is a huge milestone for us,” concludes Venger. “Everything else is humanly controllable. We can pre-plan around anything that arises from this point forward, even it entails a hurricane. When it comes to the piling work, you’re up against the unknown. You never know what you’re going to find when you’re digging the hole. We had three wells put in for this project and pumped from two of them. We reached 1,000 gallons of water per minute from a well absorption point of view. We had the third back-up well ready but luckily, we didn’t have to use it. From this point forward, we’re off to the races.”
Construction work on the tower proper will begin in early 2016, with a completion date for One Thousand Museum expected in late 2017. When finished, One Thousand Museum will undoubtedly become a landmark building – one that will transform the ambitious creative vision of Zaha Hadid into the stunning reality of luxury living – thanks to the expertise and experience of an industry ready and willing to rise to the challenge.