The first three years of the project were focused on upgrading the arterial streets to handle additional traffic generated by closures on the interstate when work began on the Interchange itself in late 2014. In addition to the new storm sewers, the project included contracts for 21 bridges, 30 walls, 11 noise barriers, concrete pavement, 20 million lbs of structural steel, steel tub flyover bridges with stainless steel concrete deck reinforcement, pre-stressed concrete girder bridges, earthwork, structure and pavement demolition, intelligent transportation systems, large diameter drilled shafts, MSE walls with precast panels, utility relocations and pile supported foundations. The current project is valued at nearly $200 million.
The main challenge faced by contractors was the aggressive schedule, combined with the uncertainty of harsh weather conditions. WisDOT scheduled completion of the Interchange structures before December 2015. The Phase 1 core contract running through December, 2016 requires the Blue Mound Road Bridge over Highway 45 to be demolished and rebuilt before Memorial Day 2015. A massive new pumping station must be installed by the end of May 2015, and a 60-inch storm sewer must be tunneled underneath the interchange.
County Materials Corporation supplied a wide range of reinforced concrete pipe ranging in size from 12-inch to 96-inch diameter in Classes III to V. In addition, there was nearly 600 feet of Class HE III 58-inch x 91-inch and 77-inch x 121-inch horizontal elliptical pipe along with nearly 1000 structures including inlets, catch basins and manholes ranging in diameter from 3-foot to 12-foot. County Materials shipped the concrete pipe and structures from the company’s various locations throughout Wisconsin.
The Zoo Interchange is a major transportation link in Wisconsin, and a significant component of America’s Interstate Highway network. The core materials for the interchange are concrete and steel. It is designed to be a resilient asset for the city and state for generations. Large quantities of reinforced concrete storm sewer pipelines and culverts are critical infrastructure that will function as long as the design life of the intersection. The ability for designers to specify different classes of standard engineered pipe with varying strengths and shapes to save costs of installation, while accommodating earth and live loads of traffic, suggests that WisDOT has strong specification guidelines and rules that support good engineering practices.
Article courtsey of: Concrete Pipe News, Spring 2015