ASPIRE is a quarterly magazine published by PCI in cooperation with the associations of the National Concrete Bridge Council. The editorial content focuses on the latest technology and key issues in the Concrete Bridge Industry.
Issue link: http://www.aspiremagazinebyengineers.com/i/306186
C R E AT I V E C O N C R E T E C O N S T R U C T I O N 40 | ASPIRE , Summer 2011 F or T.Y. Lin International (TYLI), a successful pr oject is one wher e str uctural and safety requirements are met, and the aesthetic performance of the bridge is appropriate to the budget and expresses the values of the community. To ensure the design has visual consistency, the approach to the design process becomes holistic from the beginning of the project, which includes all critical disciplines. One important factor in this integrated design process is the incorporation of aesthetic lighting. The aesthetic lighting design for the Cypress Avenue Bridge in Redding, Calif., and the Stewart Street Bridge in Dayton, Ohio, employed the same integrated process, but yielded very different final results. Cypress Avenue Bridge The Cypress Avenue Bridge form takes its cues from the natural environment, and is conveyed through curving lines and soft surfaces along all the exterior edges (as if softened by the Sacramento River). The city and design team were able to identify two aesthetic lighting goals: first, to demarcate the river and second, to gently wash the edge of girder face with light. To highlight the river spans, large lanterns were designed to include dichroic glass that changes color based on the viewing position and to be illuminated by cold cathode lamps. The glass was designed and manufactured by Architectural Glass Art, while Illumination Arts executed the lighting plan. In addition, LED fixtures were selected for the roadway and edge girder lighting. The fixture selection resulted in a soft, low-energy illumination. By softly illuminating the girder from abutment to abutment, local residents and park users can now enjoy the overall structure. The lanterns draw attention to the river crossing for travelers along Cypress Avenue. stewart street Bridge In Dayton, Ohio, the new Stewart Street Bridge is essentially the "front door" to the city and the University of Dayton. The community group wanted to use the bridge to enhance activity along the river, and to make a statement about the ever-growing pride of the community. T h e S t e wa r t S t r e e t B r i d g e t o o k o n a ver y modern aesthetic theme through the development of dramatic Y-shaped piers, which are split both longitudinally and transversely. The aesthetic lighting, developed by TYLI, took full advantage of the form by illuminating the in between the Y-shaped piers at night, which is the opposite of the way the piers are naturally lit during the day. The LED fixtures are fully programmable to create unique and seasonal lighting themes. The fixtures are also concealed within the superstructure and subsequently not visible to the traveling public. They are also located above high water, keeping the lenses clean and unaffected by rain or snow. By hiding the fixtures, the piers literally glow at night. Whether used as a soft accent or to make a dramatic statement, aesthetic lighting is an inexpensive way to enhance a bridge's appearance. TYLI believes that any aesthetic lighting design should be engaged fully into the design process from the beginning in order to ensure seamless integration into the overall project development. The Cypress Avenue Bridge and the Stewart Street Bridge are each a perfect case in point. _______ Michael Fitzpatrick is bridge architect with T.Y. Lin International in San Francisco, Calif. To read more about these projects, see the articles on pages 36 and 14. Lighting Design for Cypress Avenue and Stewart Street Bridges by Michael Fitzpatrick, T.Y. Lin International Curving lines and soft surfaces are highlighted on the Cypress Avenue Bridge in Redding, Calif. Photo: T.Y. Lin International. The LED fixtures illuminating the Stewart Street Bridge in Dayton, Ohio, are fully programmable to create unique and seasonal lighting themes. Photo: Woolpert Inc. Editor's NotE Book_Sum11.indb 40 7/1/11 10:00 AM