The Phillip and Patricia Frost Museum of Science project is a state-of-the-art, 280,000-SF, multi-use science and technology museum, planetarium and aquarium constructed in Museum Park in the Miami Downtown area. The museum was designed by one of the world’s leading architectural firms and one of the pioneers of high-tech architecture, Grimshaw Architects. As part of the museum, the Living Core houses the Gulf Stream Aquarium, a 100-foot wide 500,000-gallon aquarium in the shape of a water drop, when viewed from above. The façade is a one of a kind doubly curving mortar bed and ceramic tile vented cavity structure. Project specific testing was conducted to obtain Miami Dade NOA certification. The finished tile surface is organized into a linear parallelogram pattern, with a 3/16" tolerance, superimposed on the continually changing complex curved substructure. Tiles in the parallelogram are flat, convex or concave to create an in-and-out pixel geometry texture allowing the arc of the sun to animate the façade.
KENPAT was hired by SKANSKA to provide the engineering, modelling, fabrication and installation of the exterior skin of the Aquarium building. Some of the professionals involved in this installation with over 30-years of experience in framing and construction, consider this to be the most complex structure they have ever worked on. “The combination of four realities challenged the façade delivery team: tight tolerance on a patterned compound curving façade, with a unique structural attachment and Miami Dade NOA certification requirement,” said Paul Wolmarans, CEO of KENPAT.
One of the initial tasks of constructing the outer “skin” of the building, was to ensure that the wall was certified capable of withstanding hurricane force weather conditions. KENPAT was tasked to obtain a One-Time NOA (Notice of Acceptance) certification from Miami-Dade County for the exterior wall, which required rigorous testing to meet the strict impact, water and air infiltration parameters, per Miami-Dade’s NOA requirements. Working with Radius Track, a firm that specializes in the consulting, design and fabrication of framing for curved surfaces, three test panels were designed and constructed for testing at Intertek’s test facilities in Minnesota. The impact test entailed a 9-pound 2×4 piece of wood projectile being fired multiple times at the target, at 50 feet per second.
The result: Individual tiles were damaged as expected, but the projectile could not penetrate or impact the wall itself. In addition to the impact testing, the fabrication was also subjected to severe water and air infiltration tests, exposing the unit to high pressure water to ensure the test panels could withstand rain water driven at hurricane force. The wall passed all tests with flying colors. The test results proved that people who inside the building at the time of a storm or disaster would be safe! The façade system was engineered to a deflection tolerance of L/720, capable of withstanding category 5 hurricane forces, and received a Miami-Dade NOA. After successful completion of the testing, the fabrication was approved for use on the structure.
With the testing completed, construction could proceed on the framing work. The Living Core building looks much like a ship with continually changing curved, sloping and vertical sides leading up to what looks like the prow of the ship on the east side. The west of the building looks like a ship’s stern with complex curved and rounded corners. The concrete frame of the building was parametrically modeled from detailed and multiple 3-D scans which were stitched together. Numerous iterations to “best fit” the as-designed surface to the as-built conditions were undertaken. The 3/16” tolerance for the linear pattern, superimposed on a continually changing complex curved surface, required the team to study the finished surface in real time using its interactive parametric model.
For each instance where the concrete structure was out of tolerance of where a clash was detected, the team adjusted the surface pattern to comply with the design intent. Each surface adjustment of the linear parallelogram required a new iteration of the linear parallelogram surface around the entire building, to ensure the surface pattern connected precisely. These adjustments in turn necessitated iterative refinements to the framing engineering and design. After extensive collaborative work, a final parametric model which was in sympathy with the design intent and as-built conditions was presented to and approved by the design team.
Once the framing was in place, the KENPAT team moved on to the next phase of the installation -- rigid insulation. The entire building was wrapped in two layers of dens glass sheathing installed over the framing. Over this, KENPAT applied a waterproofing membrane and then vertical and discontinuous horizontal hat channels, to create a ventilation cavity that would help avoid penetrations through the primary waterproofing system. A 20-gauge galvanized steel sheet was installed before the final surface layers were installed.
KENPAT added over 525 parallelogram tile fields in a rising, angular pattern, over the completed sub-surface. The linear parallelogram pattern superimposed on the compound curved façade created incredible complexity. Each full parallelogram contained exactly 861 tiles regardless of the shape of the skin it covered. This process called for exact placement of the parallelogram frames around the building. X-y-z coordinates from the parametric model were again translated precisely onto the surface to map the exact 3-dimensional location along the edges and at the corners of the parallelogram frames. The geometry of the parallelograms often demanded that aluminum angles be curved simultaneously in the y- and z-axes. Work tickets were developed from the parametric model to allow stretch forming of such complex curved pieces. Once the parallelograms were precisely formed with aluminum angles, the installation of the final surface layers could start.
The façade assembly structurally attaches to the concrete structure at the slab edge of the top floor for the exterior wall to “hang like a curtain”. Other attachments, including the stand-off bottom clips, are non-structural. The framing members had to precisely follow the shape of the building – approximately 25% of the surface area features a double curvature, requiring the framing to follow this form. Data extracted from the 3-D model drove the fabrication of the light-gauge framing. Specific x-y-z coordinates were established in the 3-D model, at the edges of the CFS framing members.
During installation of each CFS stud, the x-y-z coordinates were translated from the 3-D model to the field, to ensure the as-built framing system matched the as-designed model. The seamless translation from 3-D model to the field allowed team KENPAT to ensure that the geometry of the surface was per design, creating a perfect surface upon which the next layers would be built. Great precision was required during installation to ensure the exact geometry and levels of the structure. A thorough understanding of the complexity of the seven layers of build-up in the wall’s substructure and how little deviations can cumulatively affect the 3/16” tolerance was crucial to the installation team’s success.
Practically, to provide the tolerance accuracy specified for the tile parallelograms, the line of every stud was surveyed in. The surveyed line for each stud was scribed onto the concrete slab and lacquered to protect it. If a laser pointing up in the z-direction was moved along the setout line, it would always touch the outside corner of the stud in that position. The installation team worked its way around the structure from scaffolding and mobile lifts, at heights up to 50 feet. 3-D scans of the as-built work confirmed the accurate installation of each framing member in its designed position.
Each of the tile fields included a mortar base, thin set and the 3” circular ceramic tiles with flat, concave or convex surfaces in a random pattern. The design specified a ratio of 8 flat, 3 convex and 1 concave tile for every 12 tiles. KENPAT installed and grouted over 400,000 circular tiles on the exterior of this facility.
KENPAT finally fabricated and installed 1/4” stainless steel bases and trim pieces at the bottom border of the wall. These pieces included parametrically modelled and laser cut ventilation slots. The top of the structure received an intricate purpose-made aluminum parapet cap, engineered to withstand category 5 hurricane force winds.
Now, with the opening of this vast new science museum, visitors will be able to stand in the Living Core structure underneath a suspended, 500,000-gallon aquarium tank and gaze at hammerhead and tiger sharks, mahi-mahi, devil rays and other creatures through a 60,000-pound lens that will give the impression of seeing the fish from the bottom of the sea. It is this structure that KENPAT has worked on so tirelessly to create a manmade exterior as scientifically and technically outstanding as the natural science on display inside the structure.
The Frost Museum of Science Aquarium Façade project elevated industry standards through a collaborative delivery process employed by a team of experts, using virtual technology and real-world conditions to understand, interpret, engineer and fabricate a unique framing solution for a compound curving skin with a very tight finish tolerance. “The technology, engineering, and sustainability features found throughout the museum rival those on a global stage,” said museum President Frank Steslow in a spring 2017 press release. When one considers the testing parameters, the modelling/build work on the tile fields, the extensive use of 3-D parametric modeling, the iterative translation of the precise location of x-y-z coordinates for each construction layer, the engineering and construction of the exterior of the Phillip and Patricia Frost Museum of Science Aquarium building is a project truly deserving of recognition as Excellence in Construction.