Long-Span Pedestrian Bridges in the USA - A Futuristic Approach

Abstract

<p>The design of pedestrian bridges has been evolving significantly in the past few years due to emerging technologies and the application of non-traditional materials. This paper describes these trends with a number of examples of bridge designs that present unique challenges ranging from high lateral forces due to high seismicity to highly constrained site conditions. The first case study discussed is the pedestrian bridge at the new San Diego Courthouse (San Diego, CA, USA), featuring a 26 m span double cantilever inverted pendulum structure fabricated using techniques conventionally used in the ship building industry. The second case study describes the bridges at the Moscone Center Expansion Project (San Francisco, CA, USA). The latter examples employ optimally shaped box girders which minimize the deck thickness creating a seemingly minimal architectural expression. Finally, the conceptual studies for a pedestrian bridge at the LAX airport (Los Angeles, CA, USA) are described in detail. The design for the bridge was developed using structural optimization techniques. Such techniques have already been successfully applied to structures in the aeronautical, automobile, and mechanical industries where natural force flows are modeled. These fundamental principles of optimization have been used to develop two novel responses to the long-span pedestrian bridge. Both designs, though unique and simple, integrate the idea of topology optimization with modular design, resilient materiality, sustainable practices and visual transparency.</p>