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/306864
12 | ASPIRE , Summer 2010 In Folsom, California, the use of cast-in-place concrete segmental construction in this steep canyon topography greatly minimized construction impacts. (see Folsom Lake Crossing, ASPIRE™, Winter 2009). Photos and figure: CH2M Hill. P E R S P E C T I V E Bridges are a critical component of our national highway infrastructure. The phenomenal replacement cost of our aging national inventory of approximately 600,000 highway bridges is estimated to be on the order of one trillion dollars. These structures, which are the backbone of our national highway system, have seen increased traffic volumes and environmental exposures that were not imagined during their original design and many have surpassed their expected service lives. As a result, approximately one quarter of the national bridge inventory is currently classified as "structurally deficient" or "functionally obsolete." The increasing backlog of deficient bridges raises the daunting prospect of a major ongoing bridge repair, re c o n s t r u c t i o n , a n d re p l a c e m e n t program that could extend far into the future. Faced with this problem, it is clear that the strategies of meeting lowest initial construction cost and only addressing operational requirements may no longer be the best approach for constructing a sustainable bridge infrastructure that will be a legacy we leave for subsequent generations. Current bridge design and construction practice has evolved over time in response to many different challenges and changing standards, and the incorporation of new sustainability principles in practice will see a similar process. Unfortunately, there are no "silver bullets" to address contemporary issues like lack of project financing, increasing cost of energy, and limited key resources. These are complex problems that will result in an evolution in how we design, build, and operate bridges. So what can do we do now t o d e v e l o p a s u s t a i n a b l e b r i d g e infrastructure? Strategies for Change The good news is that sustainability is not difficult to implement. Many strategies exist that, when combined, can effectively and successfully achieve a more sustainable bridge as an end product. Approaching bridge design and construction with a different angle—one that uses a holistic (systems- thinking) perspective—can do more for the environment and society than simply by Jeralee L. Anderson, University of Washington and Joe Showers, CH2M Hill Towards Sustainable Bridges Percentages of the bridge inventory in the United States that fall within various age categories. ASP10-1625.indb 12 6/21/10 12:19 PM