WorldWide Drilling Resource®

February 6 - 7, 2020 Aquarius Casino Resort - Laughlin, NV Located on the Colorado River For more information visit us online: mountainstatesgroundwater.com E-mail: info@mountainstatesgroundwater.com (480) 609-3993 WHYATTEND??? • It’s a great opportunity to visit with manufacturers & suppliers, drilling contractors & pump installers, technical & consulting firms, state groundwater officials, etc. • Attend the seminars • Visit the exhibits • Earn CEU’s • Participate in the Buck Lively Scholarship Auction & Raffle No membership is required to attend – Everyone is welcome! It’s casual & inexpensive: Bring your employees! 17 WorldWide Drilling Resource ® JANUARY 2020 Underground Work for Highway Improvements Adapted from Information by Midwest Mole Indiana’s SR 37 is a four-lane, north-south highway serving the residents of Hamilton County, the City of Fishers, and the City of Noblesville in suburban Indianapolis. As growth in the county has increased, more than 50,000 vehicles travel the corridor each day, and are regulated at each of the cross streets with traffic signals which are becoming more overloaded as time passes. Using a technique pioneered elsewhere in the region, SR 37 will be converted from a surface street to a freeway by constructing tight roundabout interchanges at existing intersections (plus one larger interchange) and depressing the SR 37 roadway. Midwest Mole was contracted to build a 2100-foot tunnel for drainage requirements, form a detention pond, and make an outlet facility to Shoemaker Ditch. The main work pit for the tunnel was built using trench boxes and is approximately 44 feet long and 14 feet wide. The company used an 84-inch tunnel boring machine (TBM) to exca- vate the tunnel using steel ring beams and wood lagging support. They equipped the TBM with an onboard electric hydraulic power pack to reduce noise, since the site was in a residential/commercial area. Based on ground investigation, the geology along the TBM align- ment was expected to be primarily glacial till, which is fairly common for the Indianapolis area, but also very complex. The till comprises pockets of water and sand, and is interlaced with boulders. Crews had to blast some of the boulders so the cutterhead could pass through. They would drill a small hole in an offending boulder, then activate a small blast or series of blasts to break up the rock. This eased the task of drilling with the TBM. Before half the length of the tunnel was excavated, over 20 boulders had been encountered. “What is interesting about the ground is that there are not connected layers of geology - just pockets of different ground types and groundwater,” said Mike Liotti, project engineer for Midwest Mole. “You can be tunnelling along and then suddenly you’re in a completely different type of ground in as little as ten feet. It’s a very challenging environment for tunnelling.” EXB