Panels & Furniture Asia September/October 2024

STRUCTURAL ELEMENTS

LEGEND 1 The Cathedral’s strength is

of the ancient Roman technique of thermal inertia maintains the interior climate with mass and radiant heat. Through displacement heating, small ducts beneath the pews cool the building from the floor. The floor plan of the building is in the shape of a Vesica Pisces which creates a spherical elevation. The Vesica Pisces is a shape of religious significance, two intersecting circles of the same radius, connected in such a way that the centre of each circle lies on the circumference of the other. Historically, this shape is an ancient sign among Eastern and Western cultures for a gathering place and a symbol among Catholics for the miracle of the loaves and fishes. Given the proximity of fault lines and non-conformance of the design to a standard California Building Code lateral system, the City of Oakland hired a peer review committee to review the design for toughness and ductility. Through the use of advanced seismic engineering, including base isolation, the structure has been designed to withstand a 1,000-year earthquake. The Cathedral’s strength is achieved through the use of glulam and steel rod space frames. The Vesica Pisces was constructed with 26 glulam ribs measuring 10 and 3/4in-wide by 99f, 9in-long that vary in depth from 30in at the base to 19 and 1/2in at the top. Between each rib are 32 glulam louvres measuring 5 and 1/8in-wide and varying in depth from 22 and 1/2 to 39in. The louvres are installed at seven different angles to optimise the light effects. In the process of designing the cathedral, the engineers at SOM were able to achieve appropriate structural strength and toughness using a structural system not recognised by building codes. This was accomplished by carefully defining the ductility requirements of the structure, modelling its nonlinear behaviour,

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achieved through the creation of glulam and steel rod space frames an earthquake back in 1989, the newly designed Cathedral was designed in mind with a lifespan of 300 years

2 After being damaged by

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testing the components that were relied on for ductility and field verifying the installation of these components. The design team at SOM worked closely with the glulam supplier to achieve appropriate finishes of the various glulam members. The use of a full-scale mock-up was instrumental in allowing the architects and engineers to see how the structure would appear when completed. This allowed changes to be made that had little or no economic impact, but improved the structure’s appearance and performance.

demonstrate that modern glulam construction should be used to build a building intended to be structurally capable and architecturally worth of lasting 300 years. The Cathedral is an extraordinary timber structure meeting demanding seismic and architectural design criterion that is more economical and aesthetically pleasing than conventional steel or a reinforced concrete moment-frame building. P This case study was prepared by APA Market Development specialist Karyn Beebe, and Paul Gilham from Western Wood Structures. It first appeared in Wood Design and Building magazine.

The design and erection of the Cathedral of Christ the Light

SEPTEMBER / OCTOBER 2024 | PANELS & FURNITURE ASIA 55

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