U.S. Supertowers, Megaprojects Retake Center Stage
For the buildings sector, 2014 has been a year of starts, stops and milestones—some very high profile. Though at least a year late, tenants finally began moving into the 1,776-ft-tall One World Trade Center, currently the tallest building in the Western Hemisphere. The observation deck is expected to open in the spring.
Also at the WTC redevelopment site, the National September 11 Memorial & Museum opened, some three years later than originally planned, and, like One WTC, a very bumpy project from a development standpoint. Silverstein Properties, responsible for four other high-rises at the site, one of which is open, announced it had secured funds to restart work on the tower portion of the 1,170-ft-tall 3 WTC, which was capped at the eighth floor.
Supertall building construction continues apace—especially in New York City, where workers topped out the 1,396-ft-tall 432 Park Avenue residential tower, designed by Rafael Vinoly Architects. Work has begun on another Big Apple "supertall": the 1,775-ft Nordstrom Tower, designed by Adrian Smith + Gordon Gill Architecture. In Chicago, schematic design is underway for an 89-story building, designed by Studio Gang Architects.
Another kind of supertall tower—for observation and entertainment—won voter approval in Miami. The estimated $430-million SkyRise Miami project, planned to rise 1,000 ft, is in the very early stages of construction. Arquitectonica is the architect.
Megadevelopments have returned to the U.S. Arquitectonica's $1.1-billion mixed-use Brickell City Centre, also in Miami, includes 5.4-million sq ft of office, residential, hotel, retail and entertainment space on a 9.1-acre site. The project, which contains three high-rises, will be completed in stages by the end of this year, says Swire Properties, the developer.
Back in New York City, work is moving along at Hudson Yards, which ranks as the largest private development in U.S. history. The site will ultimately include more than 17 million sq ft of commercial and residential space, a school, a cultural center, a hotel and 14 acres of public outdoor space. Plans call for five office towers.
Work on the $1.1-billion Wilshire Grand Center in Los Angeles ended up in the record books in February with the largest continuous concrete placement—21,200 cu yd—for the 73-story tower's mat foundation. In San Francisco, crews dug caisson shafts as deep as 262 ft for the $325-million 181 Fremont, a combo office and residential tower next door to the massive Transbay Transit Center and office tower construction site. Several other large projects are within a stone's throw in the neighborhood.
In the sports construction arena, the San Francisco 49ers stadium, now called Levi's Stadium, opened this summer on time. And work began in the spring on the $1.2-billion Atlanta Falcons stadium, which is designed to sport a movable roof that opens and closes like a camera lens.
In 2014, the Applied Technology Council released an ambitious plan to push the needle forward on high-strength reinforcing steel. The Road Map for the Use of High-Strength Reinforcement in Reinforced Concrete Design lays out 39 research projects costing $27 million, to be executed over five years. Results will be used to overhaul the concrete code. The aim is to drastically improve concrete structures by reducing material needs, rebar congestion, labor and cycle time per floor—thus cutting schedules and increasing quality and safety.
