WorldWide Drilling Resource

Working Hard to Construct Extraction Shaft Adapted from Information by Deep Foundations Contractors Deep Foundations Contractors (Deep) had to drill in a confined space within an extraction shaft on the Egl inton Crosstown Light Rai l Transit Project (Crosstown) in Midtown Toronto, Canada. Crosstown is an infrastructure project with a nearly 12-mile-long corridor, with six miles running underground. The confined space of the 107-foot-deep extraction shaft, where two massive tunnel boring machines (TBMs) would be lifted from the ground at the end of their subterranean journey, was the first of many chal- lenges the firm would overcome while working above and below the buzzing streets of the city. Deep was awarded the contract to exca- vate and shore the launch of the extraction shafts for the two TBMs; build two emergency exits for the TBMs; and construct head walls for two future stations. If successful, Deep’s work would allow the two TBMs, known as Don and Humber, to continue their under- ground journey uninterrupted. The costs asso- ciated with stopping their progress would be incredibly prohibitive, so failure was not an option. Work on the project started in April 2014, and Extraction Shaft 3 (ES - 3), where the TBMs would be extracted, was located at one of Midtown Toronto’s busiest intersections. Workers barely had room to breathe, especial- ly inside the shaft. The crew had to put in the preparation work, making sure everyo ne knew what they were doing, as well as having clear procedures in place for what was happening as work progressed. The concrete was placed under polymer slurry using the tremie method. The cre w poured each pile with a flexible hose connected to a sectional tremie pipe fed by a pump which was positioned above the s haft. At this point, the pipe was lowered to the bottom of each hole. As the concrete was placed, the slurry in each hole was dis placed. Workers scrutinized the volume and rate of concrete placement to guarantee the piles were uniform and of high qual ity. Deep’s crews persevered 24 hours a day, six days a week to complete the 29 s ecant piles under a rigorous schedule. By this time, the northbound TBM had already broken through. The south- bound TBM and a 50 - person crew were crawling quickly toward ES - 3. Everyone had to be out of the shaft before break- through. In March 2017, the lower drilling came to a successful conclusion. Fiberglass crumbled and water spewed as the cut- t ing head of the second TBM, Don, broke through the wal l of ES - 3. The project was completed successfully to the satisfaction of all parties involved. Editor’s Note: In between our print issues, the WWDR Team prepares an electronic newsletter called E-News Flash . Based on readership, this was the most popular E-News Flash article of the month. Get in on the action and subscribe today at: www.worldwidedrillingresource.com We have stainless steel and metal valves, as well as plastic cycle valves! For more info call: (800) 364-2124 or visit us online: www.barrettsupply.com Proudly made in the USA Sales rep territories available. engagements f 90% of his busin tion, and motiva customer service sales, manageme in 25 countries o given over 4000 Speaking Profe Tim Connor, CS rom previous ess is repeat tional topics. communica- nt, leadership, n a variety of presentations ssional) has P (Certified Ti S k 4 @ 704-875 new client “G Call him and a clients. il -1230 uarantee”. sk about his TimConn m pea s u or.com gma .com 54 FEBRUARY 2018 WorldWide Drilling Resource ®