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Fig. 6: Construction access from the north portal also needed to be created be a four-lane section, and will extend SR 265 (the Lee Hamilton Highway) 4 miles (6.4 km) from its current termination at SR 62 to the bridge. On July 26, 2002, the two governors of Kentucky  and Indiana announced that the East End Bridge would be constructed, along with a new I-65 downtown span and a reconstructed Kennedy Interchange, where three interstates connect. The cost of the three projects will total approximately $2.5 billion and will be the largest transportation project ever constructed between the two states. Construction began in 2014, with the entire project being completed by 2024. One of the challenges was dealing with a particular property of historic value—the Drumanard Estate—that was in the direct path of the project. The answer: two 1940 ft (591 m) tunnels under an undeveloped part of the estate for the bridge approach. These tunnels will be the second longest in Kentucky and the longest that will allow hazardous materials. The Drumanard Estate and the decision to tunnel under it is not without controversy and with proponents and detractors. In fact, this is a longstanding issue that has blocked Louisville’s East End Interstate bridge for 50 years. So, what makes the Drumanard Estate so historic? The Olmsted Brothers, world-renowned landscape architects behind New York’s Central Park and many parks in Louisville, designed the layout of the grounds, gardens, landscaping, and plantings per the request of the original owner, William Strater. Strater purchased the property around the turn of the twentieth century. Tragically, Strater drowned in Harrods Creek before he could reap the fruits of his landscaping dream. It wasn’t until 1929 that Strater’s wife brought her deceased husband’s dream to reality and had the estate built for her son, Edward Strater, complete with the Olmsteds’ plans. The 47 acre property stretches from Wolf Pen Branch Road all the way down to Harrods Creek. Fig. 7: Ventilation tubes exiting the south portal during construction Fig. 8: Formwork for tunnel entrance Most of the original plantings around the mansion have been taken out to prevent standing water from eroding the foundation. But inside the home, a full transformation is underway to restore and upgrade the palatial estate as required to hold the preservation easement. It will also keep a historic part of the Country Estates of River Road intact. The tunnel was excavated using drill and blast methods. Alternative methods, including roadheaders or impact hammers coupled with line drilling of the profile, would also be considered, subject to approval by the engineer. These measures were augmented with shotcrete and invert concrete protection where the tunnel encountered poorer rock mass conditions. Portions of the entrance of the tunnel also received shotcrete and anchor solutions. WVB East End Partners, for the most part, used robotic equipment to place wet-mix shotcrete to stabilize loose rock during the initial support. As with many of these projects, as different conditions are encountered, combinations of the various Shotcrete • Spring 2016 15


2016SpringShotcreteEMag
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