August 2009 | Volume 79, Number 8

ON THE COVER:
The design of the Cathedral of Christ the Light, in Oakland, California, incorporates a southern window—the Alpha Wall—representing the Christian view of the beginning of the world. The window is bounded by a roof compression ring, ribs made of laminated timber in which the layers are glued together (“glulam”), and a reinforced-concrete wall. (Photograph by Tim Hursley.)

Features

Amazing Space

By Mark Sarkisian, P.E., S.E., LEED AP, M.ASCE, Peter Lee, P.E., S.E., LEED AP, M.ASCE, and Eric Long, P.E., S.E., LEED AP

When the Roman Catholic Diocese of Oakland, California, began to plan for the replacement of a cathedral damaged in 1989 by the Loma Prieta earthquake and eventually demolished, it envisioned an edifice that would use the interaction of light and structure to alter its appearance throughout the day. Designing a cathedral with an ethereal look that would also be able to withstand some of the world’s strongest earthquakes—from the nearby San Andreas and Hayward faults—required inspired engineering.

Untangled

By Paul E. Provost, P.E., and Robert Warshaw, P.E., F.ASCE

For years a busy set of intersections in Newburgh, New York, forced travelers on two interstate highways, including the New York State Thruway, to use short stretches of local roads to make connections, complicating traffic patterns and causing congestion. A nearly completed redesign of the interchange system will eliminate the bottlenecks, smooth the flow of traffic, and provide an environmentally benign consolidated maintenance area for New York State Thruway personnel.

Custom Fit

By Don Bergman, P.Eng, Andrew Griezic, P.Eng., and Chris Scollard, P.Eng.

The first completed extradosed bridge in North America is the North Arm Bridge, which carries two rail tracks and a pathway for pedestrians and cyclists across two navigable channels in Vancouver, British Columbia. The extradosed design, with its slim girders and single plane of cables at a shallow angle, keeps the bridge beneath the flight path of a nearby airport yet far enough above the navigation channels to allow ships to pass.

Meeting a Higher Standard

By Daniel P. Lynch, P.E., and Thomas A. Broderick, P.E.

The Broad Run Water Reclamation Facility, in Ashburn, Virginia, uses membrane bioreactor technology in a novel manner, incorporating it along with granular activated carbon filtration and disinfection by ultraviolet light. Capable of meeting extremely stringent water reclamation standards, the 11 mgd (41,635 m³/d) plant is expected to lead the way in redefining viable approaches to wastewater treatment.

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