Super Excavators of Menomenee Falls, Wisconsin, was subcontractor on a project that received the National Award of Merit in the transportation category from the Design-Build Institute of America. The Ohio DOT I-71/I-670 Interchange – Columbus Crossroads was the largest highway project ever undertaken in central Ohio, and the first microtunnel project for the Ohio DOT. The project added lanes, bridges, and retaining walls over a 2-mile stretch of the I-71/670 junction. The design-build approach resulted in its completion two years ahead of schedule and substantial cost savings. General contractor was Kokosing Construction Co. Inc. of Columbus, Ohio.
Super Excavators installed 4,312 lf of new separated storm and sanitary sewer lines using 54-in. ID RCP in five drives in downtown Columbus with its Akkerman SL60 microtunneling system. Six shafts were constructed at depths ranging from 16-35 ft. Microtunneling took place from October 2011 to June 2012. The ground conditions varied from soft sand, stiff clay, to wet sands with cobbles and boulders and ground water was present throughout all of the alignments.
The award will be presented to design lead CH2M Hill at the Design-Build Conference and Expo this fall in Dallas, Texas.