Going Out on a Ledge with High-Rise Construction
Most high-rise towers follow a similar design pattern. The most common design is for the structure to have floors that stack over one another with virtually little deviation from one floor to the next. Look at any city skyline and you will see an abundance of buildings that fit this mold. The consistency of the floorplan allows for easier and less expensive engineering and construction due to the design pattern’s repetitive nature.
This cannot be said about structures designed by architect Frank Gehry—one of the most influential architects of our time. Mr. Gehry’s unique and iconic designs include the Guggenheim Museum in Bilbao, Spain, the Louis Vuitton Foundation building in Paris, and the Walt Disney Concert Hall in Los Angeles. Frank Gehry-designed structures always seem to push the limits as to what is possible, making them world-renowned attractions.
Mr. Gehry’s latest project in Los Angeles is The Grand LA (“The Grand”). Located directly across from the Walt Disney Concert Hall, The Grand encompasses an entire city block with a hotel, retail and residential units. The Grand is destined to become a premier destination for visitors to enjoy the offerings of the downtown Los Angeles arts district.
What makes a Frank Gehry design so fascinating is what also makes it so challenging to build. This was certainly the case for Conco when constructing The Grand. The design called for changing dimensions of every floor; therefore, proper layout took on added importance. Daily and often hourly communication was necessary to ensure that Conco crews had the supplies they needed to perform the work at hand for the changing formwork designs. Elevated slabs and walkways more than 50 feet above the courtyard necessitated a shoring and formwork plan not found on typical construction jobs.
A particularly unique and challenging aspect of The Grand occurred on the 32nd floor of the residential tower. The design called for the concrete slab with a 54” beam to be poured 6 feet beyond the perimeter of the building. Known in the industry as a cantilevered slab, you can imagine the challenges of building and pouring a slab weighing in excess of 90,000 pounds more than 240 feet in the air, without a structural foundation directly below to support it. To accomplish this difficult task, Conco’s in-house structural engineer, Dean Chandler, calculated load bearing capacities with an added safety factor and developed a shoring plan to support the weight of the concrete slab. Conco then educated its crews on the design and communicated a pre-task safety plan containing individual responsibilities for erecting and pouring the slab. Even stripping of the formwork for the poured slab posed challenges that had to be carefully laid out if this task was to be accomplished successfully.
Building a project like The Grand requires group commitment to accomplish exceptional work. Conco, as part of a dedicated group of subcontractors working under Related and AECOM, is fortunate to have great people capable of great things to achieve this goal. The Grand has changed the skyline of Los Angeles forever and gives all who participated in its construction a sense of pride and accomplishment.