Miami’s First Supertall Will Be Hurricane-Proof
Last month, developers broke ground on what will become Miami’s first supertall skyscraper, a 100-story tower that also will be the city’s first 1MSF building.
The Waldorf-Astoria residential tower looks like stack of glass cubes precariously perched atop each other Jenga-style, which no doubt increased the engineering challenge of making downtown Miami’s first supertall about to withstand 100 MPH hurricane-force winds.
The tower, which will include cubes full of hotel rooms and luxury condos—205 hotel rooms and 360 condos—will be the tallest residential building south of NYC when it is completed in 2027. PMG is developing the project.
Making any building stable in hurricane-force winds is a challenge anywhere. But making a building hurricane-proof in a city at sea level in a state without basements that sits on porous limestone requires a quantum leap forward in building design.
The foundation for the Waldorf Astoria tower in Miami is being drilled deep into the earth, past the limestone and into solid rock. The developer also is utilizing a new technology called “deep soil mixing” to strengthen the ground beneath the project to minimize vibrations to the buildings adjacent to the site during construction.
The dampening of vibrations is a precaution against what is suspected to be a cause of the Champlain Towers condo collapse that killed 98 people at a beachfront near Miami. Pile driving of foundation beams at a neighboring construction site weakened the pool deck that gave in under the condo tower before it collapsed.
The developers involved in the construction project next to Champlain Towers reached a settlement as part of a $1B damage suit resulting from the building collapse.
PMG told the Wall Street Journal that the Waldorf tower will require Miami’s first tuned mass damper, a pendulum-like device that will be installed at the top the building to keep it from swaying in the wind.
A tuned mass damper, also known as a harmonic absorber or seismic damper, is a device mounted in structures to reduce mechanical vibrations. It usually consists of a mass counted on one or more damped springs that have oscillation frequency that can be tuned.
A tuned mass damper atop the 1,667-foot tall Taipei 101 tower—the tallest building in the world at the time it opened in 2004—successfully withstood the winds of the most powerful storm to hit Taipei, Typhoon Soudelor in 2015.
The tuned mass damper at the top of Taipei 1010 is an enormous—an 18-foot-diameter, 728-ton sphere—weighted ball that sits on hydraulic cylinders and shifts its weight to counteract the building’s movements. The contraption takes up the entire space between the 87th and 92nd floors of the Taipei tower.
In the winds of Typhoon Soudelor, the damper—meaning the 728-ton ball—moved a full meter from its center position, the furthest it has ever moved.