The Imaginative Engineer
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GREAT ACHIEVEMENTS notable structural engineers He used these materials to express the ideas within the architecture. The Imaginative Engineer Peter and his team combined advanced structural analysis tech- Peter Rice (1935-1992) niques with investigations of materials By Lorraine Lin, Ph.D., P.E. and Bruce Danziger, S.E. to develop structural systems appropri- ® Peter Rice’s approach to structural engineering expands our under- ate for each material. He believed that standing of the engineer’s role. Peter contributed to the design of build- materials should be detailed to express ings considered icons of structural achievement today. These include their true nature. the Pompidou Center and the “greenhouses” at La Villette in Paris, the “I have noticed over the years that Pavilion of the Future for the 1992 World’s Expo in Seville, Lloyd’s of the most effective use of materials is Greenhouses at LaVillette, London and the Sydney Op- often achieved when they are being Paris. Materials: Tempered era House. Many of his col- explored and used for the first time. Glass and Cables. Architect: laborators, such as architects The designer does not feel inhibited by Adrien Fainsilber. (©ARUP) Renzo Piano, Richard Rogers precedent. In any of these structures, and I.M. Pei, areCopyright today re- there is a simple honesty which goes straight to the heart of the nowned in their field partially physical characteristics of the material and expresses them in as the result of their collabo- an uninhibited way.” ration with Peter. An Engineer Imagines, Peter Rice Peter was a humanist and these beliefs are clearly pres- The design team for the Pompidou Center, which included Peter ent in his work. As a young and the architects Richard Rogers and Renzo Piano, adopted the “ger- man, he found himself over- berette” solution to achieve the long spans required to support a heavy whelmed by places like the library that could be Louvre Museum in Paris or moved anywhere in the the National Gallery in Lon- building. One of Peter’s don, having grown up in rural main contributions was Ireland away from the urban Peter Rice on site in Sydney (©ARUP) his insistence on the use centers of culture. He aimed of cast steel for these piec- to construct buildings where ordinary people felt good, not alienated es. Each gerberette was or intimidated by their environment. Peter looked to the history of cast to achieve the articu- structural engineering, particularly the Victorian engineers, for inspi- lated profile, reflecting ration, noticing that the engineer’s presence was still evident in these magazinethe piece’s internal stress earlier structures. Buildings such as the great nineteenth century rail- distribution under loads. way stations or the Grand Palais in Paris showed the engineer’s person- S T R U C T U TheR gerberette actedE as a ality in the choice of materials, detailing of the joints, and methods of short beam propped on a fabrication and construction. circular column and tied Pompidou Center, Paris. Materials: Cast Steel down at the end with a Gerberette with Hierarchical Steel Structural circular bar. Cast steel “This is the positive role for the engineer’s System. Architect: Rogers & Piano Partnership. was considered an old but genius and skill: to use their understanding © ( Bird Wong) unreliable material at the of materials and structure to make real time, so the team used the new science of fracture mechanics to help the presence of the materials in use in the convince the French building authority of the soundness of the design. Gerberette, Pompidou building, so that people warm to them, want This solution enabled the suspended trusses to achieve the required Center, Paris (©ARUP) to touch them, feel a sense of the material 147 feet (44.8 m) span. itself and of the people who made and Peter recalled his sense designed it. To do this we have to avoid the worst excesses of of achievement after the industrial hegemony.” the Pompidou Center An Engineer Imagines, Peter Rice opened after watching an old woman sitting Three themes run consistently through Peter’s work: Innovative use quietly stroking one of materials and structural form, strong creative collaborations, and of these massive ger- successfully challenging the building industry to construct beyond berettes on the fourth conventional boundaries. Peter once said that his engineering enabled floor — neither afraid him to explore the joy of experiencing successful architecture. nor intimidated by this very modern design. Materials For the Menil Collec- Peter’s repertoire of structural materials included not only steel, con- tion in Houston, Peter and Renzo Piano made Menil Collection, Houston. Materials: Ferro-cement crete and timber, but also less obvious choices such as glass, stone, cast and Cast Ductile Iron. Architect: Renzo Piano the decision to use steel, cast ductile iron, Teflon fabric, polycarbonate, and ferro-cement. Building Workshop. (©Richard Bryant) STRUCTURE magazine 52 January 2007 from the combination of materials and of blurring the distinction be- tween structure and cladding. When the “greenhouses” at LaVillette were constructed, the design was immediately recognized as a breakthrough in glass technology. Glass is a highly transparent, strong but brittle material. The cur- tainwall design built upon previous innovations at the Willis Faber Dumas Project in Ipswich, England, where glass panels are suspended in tension for gravity loads. The design at La Villette incorporated® ad- ditional innovations: The tempered glass panels have drilled counter- sunk holes for point supports (i.e. spider fittings); spherical bearings keep all loads in the glass plane and eliminate local bending effects; and, the horizontal cable trusses resist out-of-plane wind forces, which required mastery of the non- linear behavior of the tension structure. Many people con- tributed to the final design of IBM Traveling Pavilion. Materials: Timber and Polycarbonate. Architect: Renzo the glass façade: the design © Piano Building Workshop. ( ARUP) Copyright architect Adrien Fainsilber, ferro-cement combined with cast ductile iron trusses to create the lou- Peter’s team at RFR including vers for controlling daylight inside the museum. Ferro-cement has a soft his co-directors — Martin grainy texture, which both reflects and evenly diffuses natural daylight. Francis (who worked previ- Ductile iron, although not as strong as cast steel, has high resistance to ously with Pilkington Glass) cracking and does not require heat-treatment after casting. The use of and Ian Ritchie (both had cast iron for the trusses allowed for the articulated form possible with worked on Willis Faber Du- casting, without the distortions which typically result from reheating. mas) — and the French firm Construction of the louvers required tracking down a patented method Boussois. The creation of the of spraying ferro-cement into moulds with multiple layers of mesh re- floating glass boxes at La Vil- inforcement. The choice of materials helped make the Menil Collection lette started the explosion of a great success — subtle and graceful. point-supported glass façades For their next collaboration, Peter and Renzo used timber, poly- Greenhouses at LaVillette, Paris. Materials: we see today. carbonate and cast aluminum to construct the IBM Traveling Tempered Glass and Cables. Architect: Pavilion. Although transparent, polycarbonate has high toughness Adrien Fainsilber. (©ARUP) continued on page 55 but limited strength, which made it ideal for a single-story demountable structure. The semi-circular “truss” structure used tim-magazine ber struts for the top and bottom chords, and polycarbonateS pyramidsT for theR shear U C T U R E elements. Push-fit connections with rubber blocks reduced stress concentrations, due to the different thermal expansion coefficients of polycarbonate and timber. Cast aluminum ADVERTISEMENT – For Advertiser ADVERTISEMENT Information, visit connections expressed the structural nature of the timber struts — strong in tension and compression but weak in shear. The IBM Traveling Pavilion’s special character resulted www.STRUCTUREmag.org Structural Detail for the IBM Traveling Pavilion. Materials: Cast Aluminum, Glued Stainless Steel Blocks & Rubber Blocks. (©ARUP) STRUCTURE magazine 53 January 2007 A_FP-ad-working.indd 1 12/6/2006 1:43:22 PM The self-stabilizing stone façade of the Pavilion of the Future in Throughout his career, Peter drew upon the experts at Ove Arup and Seville built upon the innovations at LaVillette. The design was a Partners from a range of disciplines – including structural, mechanical, collaboration with the architects Martorell, Bohigas, and Mackay. electrical, lighting, and acoustics – to expand the impact of engineering The standard stone unit was 32 x 32 inches, composed of smaller on generating architectural forms. Another lifelong collaborator was 8 x 8-inch subunits. Stone is Tom Barker, responsible for the innovative mechanical systems used at strong in compression, but its the Pompidou Center and Lloyd’s of London. use in arch structures is limited by stability rather than strength. ® Peter and his team at Ove Arup and Partners designed the lightweight stone blocks to perform similarly to classical stone arches, not as precast elements clad in stone. This meant designing the stone arches to allow for adjustments in their geometry due to changing loads, including the formation of hinges. Modeling this type of behavior Copyrightrequired the invention of a new method of non-