Enabling collaborations

Today, shared Building Information Models (BIM), rather than just physical models, as with Otto’s early projects, allow for feedback and integration between all the building professions, including that of the construction team. Adams Kara Taylor (AKT), a London-based structural and civil engineering firm of 40 people, will engage an architect’s ideas for a project design, but, as engineer Hanif Kara says, they “do not pretend to be the architect.” Key to the firm is teamwork and a constant dialogue with the architect. An in-house mathematics think tank with computational specialists assists teams, and it is common to see five engineers from five countries hunched over one computer as they jointly solve problems. AKT’s nonhierarchical studio encourages creative thinking and innovation, but not at the cost of technical competence, achieving what Kara calls “great engineering rather than bad architecture.” For its work on the Peckham Library in London (2000), with Alsop & Stormer Architects, the concrete-filled steel columns angle to support a cantilevered upper volume. Appearing like an upside down L-shaped volume, the building’s structure freed Alsop from traditional constraints, opening the library’s base to allow for public space. Kara, who worked for Anthony Hunt and also teaches at the Architectural Association in London, engineered Zaha Hadid’s Phaeno Science Center in Germany (2005), where structural redundancy was eliminated so that the walls and concrete slab could combine as a continuous shell to achieve the fluid space the architect desired. Currently, Kara is collaborating on the design with Foreign Office Architects (FOA) of the John Lewis department store in Leicester, England (2007), that will also include retail and a cinema. AKT’s proposed structural design enables FOA to foreground an intricate lacy glass facade by engineering large spans for an atrium, an auditorium, and loading dock areas, in addition to glass walkways through the atrium.

Before leaving to form her own firm, at Arup Jane Wernick engineered Hadid’s curvilinear concrete Ski Jump in Bergisel in Innsbruck (2002) and the competition phase of Angelil/Graham/Pfenninger/Scholl’s Portland Aerial Tram in Oregon. Taking into account what Peter Rice taught her when she was at Arup, to “let the architects in on their secrets,” Wernick says she always explains her process at the outset of a project. Among her more notable achievements at Arup, her structural challenge for Marks Barfield Architects’ London Eye ferris wheel (1999) was to design a 500-foot-high structure that moves, but would be stable and strong. Not surprisingly, she found the bicycle wheel, as a tensegrity structure, to be the most economical form. She resolved the structure with landside pylons supporting the wheel at the hub, with the spindle cantilevering out to allow the wheel to be suspended over the Thames River. Although unusual for historic London, the structural spectacle of the Eye has become one of the city’s most exquisite examples of its engineering eminence.

Many times, the collaboration between architect and engineer results in buildings where intensified structural patterns emerge from a mathematical or nature-derived basis that is enabled by digital tools

to become a kind of “deep decoration.” Tristram Carfrae, of Arup’s Melbourne office, employed the concept of bubble structures for the Watercube National Acquatics Center for the 2008 Beijing Olympics, designed with PTW Architects of Australia. The center’s five pools are enclosed in a structure filled in with ETFE foil cushions—similar to those used at Grimshaw Architects’ Eden Project in England (2001)—that both physically and literally represents a swimming pool. Rather than adopt Frei Otto’s soap bubble investigations from the Munich stadium, Arup explored the connectivity of cellular arrays to combine the surface pattern with the internal structure of a ductile space frame that supports the long-span roof structure. The varied ETFE hexagonal elements resolve both the environmental and structural design in a nonlinear, unified form.

Material focus

Many engineers are interested in the structure of materials, as well as material-as-structure. The Modernist fascination with glass, in its duality of fragility and strength, in addition to its varying qualities of transparency and translucency, has played a notable part in many engineers’ oeuvre. This can be found in the early work of Peter Rice’s bracketed glass wall systems for the Grand Serres of the Science and Technology Museum in Paris’s Parc de la Villette, with architects Adrien Fainsilber & Associés (1986), to structural glass systems of such contemporary practices as Dewhurst Macfarlane, Schlaich Bergermann und Partner, and Werner Sobek. In June, Rice’s Paris-based firm, RFR, completed the structure for a 460-foot-long toroidal transparent volume to expand the Strasbourg TGV train station, designed by the architect Jean-Marie Duthilleul for the French National Railways. Relying on a slender prestressed-steel structure, the use of cold-formed curved and laminated glass minimizes its presence at the historic station. Working with Seele glass manufacturers, and incorporating solar gain analysis from Stuttgart-based climate engineers Transsolar, the project combines design, structure, and climate engineering in a truly holistic way while resulting in a bubble form at the station. Bollinger & Grohmann, working with Mutsuro Sasaki and Transsolar, devised a transparent sustainable office building in a Minimalist structure for SANAA’s Novartis project in Basel, Switzerland (2007). The extremely thin reinforced-concrete floor slabs supported by structural walls achieved the desired open floor spans, as well as transparency through the rectilinear building. With design assistance from the New York–based facade consultants Front, the translucent building appears as a thinly veiled glass box.

New York–based engineer Guy Nordenson, working with Los Angeles architect Michael Maltzan, designed the Ministructure No. 16 in Jinhua City, China, a 1,300-square-foot pavilion in a historic garden. Beginning the design with a concrete structure, the team switched to steel because of the high water table. A hybrid Veirendeel steel structure, accompanied by smaller ladder trusses, resulted in a double-perforated facade that creates an unexpected moiré pattern on the building’s skin.

Algorithms and patterns of structure

Structural engineers have been doing analysis in 3D for decades, but now they share those models with architects as digital versions of construction drawings. These models now increasingly rely on complex computer-code-based geometrical relationships that require engineers to be as much programmers as designers. Much of this work has resulted from firms designing their own software, such as Happold’s Tensyl for tensile structures or Bollinger & Grohmann’s program for trusses, though Autodesk’s Revit and Bentley’s Generative Components have revolutionized design for many engineers.

Algorithmic design processes resulted in the structural maneuvers of Bollinger & Grohmann’s proposed tessilations for Dominique Perrault’s Mariinsky Theatre II in St. Petersburg, Russia (2008). The Mariinsky’s structure is defined by a system of connected steel pyramids, like an asymmetric geodesic dome, filled in with cross ribs that radiate out to support a metal-mesh infill. The shell wrapping the theaters appears like a geode, where structure and skin are combined into one system, similar in theory to the deep decoration found on Arup’s Watercube. Cecil Balmond, one of Arup’s directors, works experimentally with algorithms with architects such as Rem Koolhaas, Daniel Libeskind, and Toyo Ito. Balmond has written a book, Informal (2002), and his projects are currently on view in The Frontiers of Architecture I exhibition at the Louisiana Museum of Contemporary Art, in Denmark, through October. The 2002 Serpentine Pavilion in London expresses many of his concepts most explicitly. Designed with Toyo Ito, the structure was based on twisted squares arranged in circular patterns, connected with their primary lines of force. The overall patterning of the shell, in crossing lines and planes, makes the skin and structure one—more similar in concept to a traditional load-bearing wall than to systems of separate structure and infill. The pavilion is a physical manifestation of an algorithm: Pattern and structure are integrated and become a form. As Balmond says, “The design started with a simple line that was repeated, releasing architecture from structure, rather than trapping architecture through the structure.” Diagonally gridded exterior-structural-skin systems have also become emblematic of his use of structure as pattern, as is the case for the diagrid structural skin of OMA’s CCTV Tower, under construction in Beijing.

Nonlinear shaping of structure is dominant in Mutsuro Sasaki’s work in strong collaborations with Toyo Ito and Arata Isozaki, as he believes there is a creative process involved in developing hypotheses regarding a structure’s shape, system, materials, and dimensions. Focusing on form-finding and shape design in curvilinear and organic forms, Sasaki bases designs on principles of self-organization in nature. Using his 3D Extended Evolutionary Structure Optimization (ESO) method, he defines his forms within a collaborative digital model to result in optimized and rational structures. For Ito’s Crematorium, in Kakamigahara Gifu, Japan (2006), the curvilinear reinforced-concrete roof shell, only 7.8 inches thick, was evaluated using Sensitivity Analysis, a systematized method for analyzing curved surfaces to determine an efficient structural shape. As he describes in his 2006 book, Flux Structure, “By means of the repetitive nonlinear analysis procedure it becomes possible to organically comprehend the evolution of structural form in the overall structure from the relationships between its shape and mechanical behavior.”

These perspectives in turn shape the future of complex space, as well as suggest the realization of new paradigms for collaboration between design, structure, and environment. The full integration of structural engineering into the process of architecture does not guarantee good architecture or revolutionary space and forms, but enables their potential to exist. Now more than ever, engineers are embracing the natural world and poetically exploiting its logic to realize architecture’s possibilities. As Ove Arup said in his “Key Speech,” the aims of his firm are not “grasped arbitrarily out of the sky or willfully imposed, they are natural and obvious.”