Hayward Baker has been performing ground improvement work on the Ohio River Bridges Project (Downtown Pursuit) along Interstates 65 and 64 in downtown Louisville since June 2013. The project is being performed for the Kentucky Transportation Cabinet and the Indiana Department of Transportation, which are joint owners of the roadway infrastructure.
The Downtown Pursuit portion of the Ohio River Bridges Project includes building a new bridge span on Interstate 65 that will carry six lanes of traffic northbound across the Ohio River from Downtown Louisville into Indiana. The existing John F. Kennedy Memorial Bridge will be upgraded to carry six lanes of one-way southbound traffic.
In addition, Interstate Highway 65 will be widened by one full set of traffic lanes on either side of the new bridge span, along with significant upgrades to the highway interchanges connecting I-65 to I-64 and I-71 in the downtown area.
The Downtown Pursuit is one portion of the Ohio River Bridges Project, a bi-state transportation investment that also includes The East End Connector, which is a new bridge crossing connecting I-264 near Prospect, Ky., and I-265 near Utica, Ind., plus related interchange reconfigurations that will complete an outer highway loop serving the transportation and commuting needs of the Greater Louisville Metropolitan Area.
Walsh Construction Co. is the prime contractor for the Ohio River Bridges – Downtown Pursuit and East End Connector projects. For the Downtown Pursuit, Walsh assembled a design and construction team consisting of Jacobs Engineering, Stantec Inc., Buckland & Taylor Ltd., and Milestone Contractors L.P. Hayward Baker was selected by Walsh Construction in February 2013 to be the design-build ground improvement contractor on the Downtown Pursuit project and in January 2014 to be the design-build ground improvement contractor on the East End Connector project.
Scope of Work
The primary focus of Hayward Baker’s work involves ground improvements for 42 separate retaining wall and embankment structures associated with the Downtown Pursuit project. The existing soils are generally urban fills followed by silty clays and silts, subsequently underlain by alluvial sands and gravelly sands with variable fines content. These soils will be improved so that they can support the new embankments and mechanically stabilized earth walls.
Based on the results from field tests carried out in various locations in the project area, Hayward Baker designed vibro replacement stone columns and rigid inclusions to improve the ground. The loading and subsurface conditions at each location were evaluated to determine which technique is required to provide the specified performance.
As Mike Minton, P.E., Hayward Baker’s project manager, explained, “In many ground improvement applications, it is adequate to simply verify the as-constructed stiffness of installed elements to confirm design assumptions, validate construction procedures and assure adequate performance.” However, the Kentucky Transportation Cabinet was particularly concerned about settlement risks related to large fill placements, requiring no more than 1 in. of settlement following paving. Due to the scale of the project and the nature of the settlement concerns, an instrumented test installation was constructed and monitored to validate the performance of the ground improvement design and construction procedures.
“For this project, because of the large footprints and magnitude of the applied stresses, adequate performance could not be assessed based on testing the near surface stiffness of discrete elements,” Minton noted. Consequently, Hayward Baker elected to construct a 25-ft tall, 200-ft long instrumented surcharge fill over stone columns and rigid inclusions to demonstrate the behavior of the improved ground at a representative location.
The instrumentation in the test embankment was set up to transmit data instantaneously to a Hayward Baker server. This allowed Hayward Baker’s design team to have real-time data on ground stresses, pore water pressure and settlement. The data from the test embankment was used to confirm design assumptions at full scale.
Going forward, Hayward Baker will install and monitor instrumentation at several additional sites within the project zone to further validate design assumptions and construction procedures.
Because of the size and complexity of the Ohio River Bridges project, Hayward Baker is drawing on expertise and personnel from several of its regional offices: Chicago, Ill., and Greensboro, N.C., as well as its office in Tampa, Fla., which specializes in rigid inclusion technology.
This is one of numerous highway projects in which Hayward Baker has teamed up with Walsh Construction to provide ground improvement services. The two companies collaborated on major road improvements to the I-80/I-294 corridor in the South Chicagoland Metro Area, the new Interstate 69 roadway between Evansville and Indianapolis, Ind., and others.
Ron Triplett, Hayward Baker vice president and project executive, noted, “Our two firms have worked together on approximately 50 projects over the past decade. That shared experience is one reason we’ve teamed up on the Ohio River Bridges project. Another reason is because we have the skill-sets plus the labor and equipment resources to meet the demanding needs of this project.”