Structures / Apple Park
- John Worley
Apple Computer Company – 1970’s Silicon Valley Landmark Company
Steve Jobs Innovator and Pioneer and Visonary He established and defined Personal Computers and operating system, ipads (tablets), ipods (digital music), iphone (cell phone and operating system), iwatch (bluetooth device connected to the world on your wrist) – each of these products defined a multi billion International market that continues today.
Seismic Isolation – 700 Earthquake Protection System friction pendulum isolators
Apple Park, consider to be Steve Job’s largest masterpiece, was designed by Foster + Partners Architects and with Arup as the structural engineer led by John Worley as SEOR. Apple Park is 175 acres of unique Architecture, Engineering and Construction that includes the iconic “spaceship” headquarters building, Steve Jobs Theater/Auditorium, a Visitors Center, a Fitness & Wellness Center, a Parking Structure, a Central Plant and a restored and relocated historic wood barn associated with the plum tree orchards that was Silicon Valley. Apple Park opened in 2017 after eight plus years of planning, design and construction. Steve Jobs himself pitched the Foster and Partners design to the Cupertino City Council in 2011 in order to assure Planning approval for this Silicon Valley landmark.
Apple Park is famous for large 4-story ring-shaped office building with the curved glass façade and canopy which is referred to as the “spaceship”. This building is thought to be the largest precast concrete building ever built as well as the largest single base isolated building in the world. The building’s curved glass façade is one feature that contributes to the unique reputation of Apple’s flagship. The main office building curved glass panels are the largest in the world. When people walk around the building the glass appear seamless the joints are small and are so far apart.
The office building has an outside diameter of 1,532 feet with a ring width of 180 feet. The ring is divided into 104 identical radial office segments, grouped into nine (9) independent 4-story wedge shaped structures that all sit on one continuous 2-story below grade structure. Eight of the wedges are for office/lab space and one of the wedges is the Restaurant & Town Square. There are entry structures where each of the wedges meet with have full-height atria that create light-filled common areas to provide social space that connect the office park to the garden space within. Continuous hallways are located adjacent to the glass at the inner and outer perimeters with the outer hallway being nearly a mile long.
The Restaurant has a quadruple-height dining hall and outdoor terraces. The Restaurant’s north-eastern facade can slide open via of two (2) huge doors of glass, each door measuring 50 feet high by 90 feet wide. These doors are the biggest of their kind ever constructed and enhance the sense of landscape sweeping through the building.
Apple Park office is a landmark base-isolated building and is the largest single base isolated building in the world. The ring-shaped building has 4 above grade and 2 below grade levels which combined create 4.9 million square feet of floor space. The entire structure is supported on 692 triple pendulum isolators by EPS with 52-inch displacement capacity, enabling the new office building to achieve Immediate Occupancy performance under the MCE for both structural and non-structural components. Structural design and analyses included near-field pulse effects in ground motions, wave propagation effects, and inclusion of vertical ground motion effects on structural and non-structural elements.
The signature interior design feature of the office building is the precast floor and ceiling system. This system innovatively integrates long-span prestressed concrete elements with exposed honed architectural surfaces, liquid radiant cooling systems, and forced air mechanical return air plenums, in addition to fire sprinklers and interior lighting. This system is a key contributor to the sustainable design while also providing a stiff and resilient floor system capable of resisting vertical ground accelerations in excess of 1g, providing a performance-based design level of minimal damage in a 2500-year seismic event. Clark Pacific provided the all the elements in the precast system consisting of over 19,000 pieces including columns, shear walls, double-tees, post-tensioned girders and collectors, void slabs, and architectural elements, erected on a base-isolated steel and concrete sub-structure. The 4,000 precast concrete structure floor slabs were factory fabricated with “Jobs Apple Quality Standard” exposed concrete architecture ceiling which is the “final” interior finish. The radial column grid requires voided slabs to span between 35 to 45 ft to radial prestressed and post-tensioned girders. The radial girders cantilever 15 feet at the inner and outer perimeter so that no columns can be seen through glass.
The underground garage parking is composed of post-tensioned, prestressed radial beams, stack framed with the columns, double tee and slab floor members, tangential beams and moat spandrels, and shear walls. Clark Pacific self-performed the design and construction of the upper office building and lateral loads with Arup. The stack framed precast concrete beam/column system was a complex frame system, designed to be compatible with the lateral force resisting precast concrete shear wall system. The radial beams cantilever to support the perimeter moat spandrels and are engineered for very low deflection criteria given they support the elaborate glass curtain wall facade above. New tee, beam and column forms were built to form the large radius corners that are prevalent throughout the garage and the entire project. Stack framing and dapped members and overall attention to hiding connections contribute to the sleek, modern look that Jobs demanded for all Apple products.
The building is the world’s largest naturally ventilated building, projected to require no heating or air condition for nine months of the year. This is achieved by using the 4,300 hollow concrete slabs which act as the floors and ceilings as an innovative air-conditioning system. In effect, this makes it a ‘breathing’ building.
The campus is powered 100 percent by renewable energy and will include 17 MW of rooftop solar. Apple Park will be one of the largest on-site solar installations in the world. The campus will be supported by a microgrid and be supplied with 4 MW of power from Bloom Energy fuel cells. Approximately 75 percent of the campus power requirements during work hours will be met by on-site generation with the remaining portion coming from a 130-MW solar project built by Monterey County and First Solar.
The Steve Jobs Theater — located at Apple Park in Cupertino — picked up a 2018 “Structural Artistry” award from the United Kingdom Institute of Structural Engineers, given to buildings which have been “transformed by the vision and skill of the structural engineer into something exceptional.” The theater’s above-ground pavilion is “the largest structure in the world solely supported by glass,” the Institute said. The glass panels that support the carbon fiber roof consist of four layers of 12-millimeter-thick plies. For this glass entry structure to work in such a high seismic region the glass bearing/shear walls are supported on a concrete ring-shaped slab that is supported on 44 triple pendulum isolators manufactured by EPS.
The theater entry lens-shaped roof rests gently on a transparent 22-foot-tall by 135-foot-diameter glass cylinder. The largest carbon-fiber roof in the world, it weighs 80 tons, with just four layers of glass forming the structural support. The roof is comprised 44 identical radial panels, which were assembled on-site and carefully craned into position onto the completed glass cylinder in a single lift. All its services, such as electric conduits and sprinkler pipes, are invisibly integrated within the thin silicone joints between the curved glass panels.
The purity of the lobby finds resonance in the ambitious custom glass elevator. In a world-first, it uses helical guide rails to rotate the car 171 degrees between levels. Two sculpted-stone stairways provide a slower descent into the belly of the Theater. The stairways culminate in a tight, compressed space, surrounded by three stone walls and a stainless-steel drum made of sliding panels.
The stone wall on the far side rises to reveal a 1,000-seater auditorium that brings people together to share in a collective experience. Great care was given to the geometry and seating arrangement to ensure the closest relationship between presenter and audience. It can comfortably host small internal gatherings as well as large events. After an event, the rear wall re-opens, returning guests to the third major space in the sequence. The seemingly permanent stainless-steel drum disappears to reveal a flexible sun-lit gathering space.
Apple is known to take a hands-on approach to much of its corporate and retail architecture, and in fact Jobs himself is credited with many of the decisions for Apple Park, though he died in 2011 before construction could start.
Apple Park’s Grand Opening was September 2017. There is little about this project that could be called usual. It is a part of the Apple way of doing things, to “think different” at every opportunity, including architecture and this engineering opportunity. Apple, as a company, is known world-wide for the design and quality of all their products. Apple Park was very much intended to be an expression of the company’s values and design standards.
- 2018 "Structural Artistry" award from the United Kingdom Institute of Structural Engineers, given to buildings which have been "transformed by the vision and skill of the structural engineer into something exceptional."