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/297000
40 | ASPIRE , Spring 2013 S TAT E M issouri recently completed a landmark proje ct , t he Sa fe & S ou nd Br idge Improvement Project—repairing or replacing over 800 of the state's worst bridges in three-and- a-half years. The bulk of this effort involved a single design-build contract for 554 replacement structures. This landmark, state-wide contract is the focus of this article, showcasing the results achieved through innovation, speed, and volume associated with this unique partnership. The remaining 248 bridges were predominantly rehabilitation and deck replacement projects, which were performed with a modified design- bid-build process through the typical Missouri D e pa r t ment of Tr a n sp or t at ion (MoD O T ) construction program. MoDOT envisioned this large state-wide effort to improve the overall condition of their bridge system. The single design-build effort was led by KTU Constructors, a joint venture of Kiewit Western Co., Traylor Brothers Inc., and United Constructors Inc., with HNTB and the LPA Group (a division of Michael Baker Jr. Corp.) as their design team. The design-build contract format afforded flexibility in the choice of design standards, and in assigning and managing risks that simply wouldn't be available in a traditional design- bid-build procurement. This contract model also allowed for a dynamic process to accommodate schedule flexibility and provide overall economies of scale in prefabricating bridge elements. These factors all contributed to the overall speed of the project. Planning The first step in this effort was selecting the bridges to be replaced. Missouri has over 10,000 bridges on the MoDOT system, and 10% were in poor or serious condition. The project budget limited the number of these bridges that could be replaced, and the speed of the project resulted in screening out any complex or environmentally challenging sites. This way a prioritized bridge list was assembled. Environmental screening and National Environmental Policy Act (NEPA) approval efforts began as soon as the bridge list was identified. This was performed prior to the design-build procurement in order to obtain NEPA clearance ahead of project start. Once the contract was awarded, the majority of environmental constraints were already targeted in the project construction schedule. Speed was a central theme of the project from the start, as stated in the project goals: • Deliver good bridges at a great value. • Minimize public inconvenience through increased construction speed and flexible schedule. • Complete construction by October 31, 2014. Procurement The procurement process started in October 2008 and consisted of a two-step, qualification or short-listing process, followed by confidential meetings with each qualified proposer to discuss its strategies and approach. The final conforming contract was signed in June 2009. Scheduling and organization were the early challenges, which were achieved by dividing the entire state into regions that corresponded l o o s e l y w i t h M o D O T 's i n t e r n a l d i s t r i c t boundaries. The schedule for each region started with the higher-standard roads and then moved into the collector road system. This proved to be a great help in managing the logistics, as cranes and prefabricated bridge components could more easily access each site, with little potential for encountering access issues due to load-restricted bridges on the existing system. Execution Four initial bridges were constructed in the fall of 2009, at the same time a monumental design effort for all remaining bridges was starting. The KTU strategy for execution revolved around standardizing the design process with Statewide Solutions Missouri's Safe & Sound Bridge Improvement Project by Ken Warbritton, Missouri Department of Transportation, and Harry Koenigs, KTU Constructors Old bridge before construction (left) and new bridge after construction (right), Andrew County Route 98. All photos: MoDOT. Showcasing the results achieved through innovation, speed, and volume. AspireBook_Spr13.indb 40 4/1/13 11:02 AM