Inner Strength

Providing short-term relief from flooding and excess capacity for future flood relief projects, the Indiana Department of Transportation (INDOT) completed

Providing short-term relief from flooding and excess capacity for future flood relief projects, the Indiana Department of Transportation (INDOT) completed a major storm sewer improvement project in the City of Evansville. A contract to construct 4,752 feet of 144-in.-diameter tunnel under Diamond Avenue, SR 66 was awarded by INDOT to Affholder, Inc. of Chesterfield, Mo. The contractor selected 96-in.-diameter reinforced concrete pipe (RCP) as the final liner for the tunnel, which directs storm water to Pigeon Creek, an Ohio River tributary.

M&W Concrete Pipe & Supply, whose Evansville facility lies within a mile of the job site, was enlisted to deliver the RCP within about seven months to complete the project on schedule. The contractor required that all products be cast before installation of the first piece. Thus, while Affholder was installing a tunnel access shaft and boring the passage, M&W fabricated RCP for the final lining.

Crews used steel ribs and oak lagging to support the earth overburden as tunnel excavation proceeded. Because the tunneling methods minimized surface disruptions, many individuals and businesses along the route were unaware of ongoing work until the release of a local newspaper story near the end of the project. By that time, all the RCP final liner was in place Û to the alleged amazement of the public, which experienced no major inconvenience.

During the entire project, from sinking of the access shaft through RCP installation to final cleanup, no more than one roadway lane was closed to traffic. The closing spanned less than a cumulative 30-day period and affected only a few hundred feet of roadway when it occurred. By contrast, a typical cut-and-cover project involving 28- to 45-ft. cuts would have required closure of at least one lane in each direction for nine to 12 months, plus closing the entire facility for weeks at a time. Given an average annual daily traffic volume of 37,740 vehicles and businesses’ use of SR 66 for access to markets, even a three-month closure might have cost several times the tunnel construction’s $6.9 million tab.

Minor utility relocations were required to accommodate the tunnel construction, and excavation of a shaft was necessary to remove the tunnel-boring machine. Yet, continuous access was maintained to land parcels along the job site, and utility service was uninterrupted along the approximately one-mile route.

Unlike the typical public works construction schedule, Affholder’s normal work day began at 7:00 a.m. and ended at 2:00 a.m., causing some scheduling and delivery problems. Compliance with Federal DOT hours-of-service regulations meant that much of the hauling work fell to lease drivers. The delivery situation was further complicated by an exceedingly small staging area for product offloading, as well as by the highly variable times required to set certain pipes. Some days, no truckloads arrived at the site; on other days, as many as 52 pieces were delivered. Moreover, since M&W was shipping to several other jobs, the tunnel contributed to the producer logging its busiest month on record.

Overall, the project’s success could be credited to combined efforts of the design and construction team and the public. Collaboration among all parties enabled completion of the tunnel with limited disruption to commuters, local residents and businesses. As a result, achieving long-term goals in Evansville did not involve sacrificing short-term benefits.

Article adapted from a report by Jim White, P.E., M&W Concrete Pipe & Supply Co. in American Concrete Pipe Association’s Summer 2006 Concrete Pipe News.



Owner Û Indiana Department of Transportation, Vincennes office; Marston Fowler, P.E., Construction Engineer

Project design Û Woolpert LLP, Indianapolis

Tunnel design Û Lyman Henn, Inc., Denver; Ray Henn, P.E., Project Engineer

Contractor Û Affholder, Inc., Chesterfield, Mo.

Public preview Û Pat Keepes, P.E., Evansville City Engineer

Producer Û M&W Concrete Pipe & Supply Co., Evansville