Structural system and building envelope

The swimming and diving complex was built on a gently sloping site, a grade change that naturally rendered the building handicap-accessible at both the pool and spectators levels and allowed much of the structure to be built into the earth, decreasing its apparent mass.

The profile of the building is also made less daunting by it semi cylindrical shape, formed by a steel-arch structural systemem, designed by Dattner and engineer EdDePaola of Severud Associates, that has several advantages over standard post-and-truss construction. While it reduces the building's exterior exposed roof area to minimize heat loss and gain, it still allows for the height required for competitive diving; the highest point on the lower chord of the truss is located almost exactly over the 10-meter diving platform. There are no columns to obscure spectators' sightlines. A cast-in-place concrete buttress supports the horizontal thrust and deadweight load at both ends of the trusses, which are triangular in section, with the apex pointing down. Long-span metal decking crosses the trusses' top chords and between the trusses themselves without intermediate structural support. Round steel sections used for the trusses also help prevent condensation (which leads to corrosion) by creating better ventilation than the flat surfaces of steel angles and I-sections would, and by discouraging the settling of dust, which attracts and holds moisture.

The eight trusses that form the roof of the building were prefabricated in three sections, so they could be trucked to the site on flatbed trailers. Construction could not have been simpler: the truss sections on each end were raised and secured to the buttresses; the middle section was hoisted between the end trusses and bolted into place; and intermediate trusses were placed between the arches for lateral stability. The construction manager, Tishman Construction Corporation, helped the architects design a false work that rolled along the bottom chord of the intermediate trusses, allowing work on ducts, lighting and electrical systems, roofing, and piping to take place above while construction on the pool proceeded below. Says Dattner, "We had to work on both to keep the construction on schedule, and because it is just too dangerous to have one crew working oover another, we constructed the false work."

The base of the building is masonry, laid in alternating bands of light and dark tan. Light-colored prefabricated insulated metal panels were installed above the masonry, with an insulated metal roof over the trusses. Inside, most of the end walls and the exposed ceiling between the trusses. are covered by perforated metal panels filled with noise-dampening material that is enclosed In moisture-proof material any water that might become trapped inside would reduce the panel's effectiveness in absorbing sound.

Most of the rooms throughout the building feature energy-saving fluorescent lighting. In the pool, metal-halide lamps are housed in open-bottomed glass shades, which provide a direct-indirect light distribution. Most of the light is reflected down to the pool, and the remainder is refracted up onto the ceiling. At the top of the exterior walls in the pool area, a narrow band of translucent, insulatеd fiberglass panels is used to admit daylight; a narrow barrel vault of the material was Installed at the roof`s highest point to bring daylight into the center of the building.

To avoid building for maximum capacity, the architects devised a method of opening up the building to accommodate temporary seating. Between each pair of buttresses on the south side of the pool where there is no permanent seating, walls made of glass doors can slide to one side Metal wall panels above the doors can then be pivoted upward until they are horizontal, creating an opening 30 feet wide by 19 feet high where bleachers can be installed. Permanent stretched-fabric sunshades protect spectators,

The swimming pool structure was made of gunite (пневмобетон) concrete sprayed at high pressure directly onto the earth over a reinforcing steel cage, with little or no extra framework, Pools, can also be made with formed-in-place concrete or with braced, heavy steel walls installed around the perimeter of a concrete floor slab. "Gunite was possible here because the soil on the site had а high concentration of naturally compacted sand," says Dattner. "It was economical, since the сon'tractor was able to dig a cavity for the pool and the accompanying trenching for Utilities with a great deal of accuracy, spraying the concrete without the expense of constructing formwork " The 12-inch-thick walls were then trowel-finished with a cementitious waterproofing material and covered with ceramic tile.

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