The original culvert crossing under Muldoon Road and over Chester Creek has long been identified by various agencies as a major obstacle to the stream's ecological functionality. The original Chester Creek culvert was a barrier to fish passage and migration, and needed to be replaced with a more fish-friendly option. As the best solution, a 19.58' x 8.83' BridgeCor® Structural Plate, 133' in length, was selected and installed for its low profile, minimal cover requirements, speed of installation and clear span. The latter made it the perfect solution for fish passage and migration.
BridgeCor enhances the established performance of 6" x 2" MULTI-PLATE® by offering nine times the stiffness and three times the strength. Not only is BridgeCor economical and easily assembled, but its bolted, segmental construction is manufactured with the industry's best equipment allowing for the longest laying length sheets in the industry. The structure was assembled in sections at the Anchorage plant and then delivered to the trench on-site, where assembly was completed.
Bristol Construction Services, LLC (Bristol), the project's contractor, completed the entire project — the road closure and demolition, the assembly and backfill of the BridgeCor structure, and the paving of the new road — in just 84 hours, under budget and with an incident-free safety record. In fact, they were the recipient of the Parker, Smith and Feek's Excellence in Construction award for exceptional work on this project.
"We built a great team of union laborers, operators, subcontractors and suppliers to ensure this project went smoothly and it paid off," said Bristol Project Manager Michael Himler. "We worked together for weeks before the actual site work started, planning for every contingency. The efforts of all team members resulted in a successful project."
Bristol employed several time and cost savings techniques throughout the project, including reuse of site materials and working with the municipality and local land owners to develop a more cost-effective alternative for a temporary stream diversion that ultimately reduced stress to the fish. Salmon were seen spawning in their new habitat last fall.
Also utilized on this project was a Vortechs® 11000 unit to treat stormwater. Vortechs is a below-ground, engineered stormwater treatment device that combines swirl concentration and flow controls into a single treatment unit. Vortechs is ideal for capturing and retaining trash, debris, sediment and hydrocarbons from stormwater runoff. The Vortechs system's large swirl concentrator and flow controls work together to create a low energy environment, ideal for capturing and retaining particles down to 50 microns.