Tunnel Business Magazine

DEC 2018

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On Oct. 4, 2018, onlookers watched as a 3.8 m (12.5 ft) diameter Robbins ompleted its epic journey. e," af- ter local rapper and activ e," overcame extremely hard rock conditions along a curving 8.0 km (5.0 mile) tunnel to bolster the City of Atlanta's water supply. The new tunnel brings the Atlanta Water Supply Program one step closer to increasing the city's water capacity to between 30 and 90 days depending on daily usage. "Our schedule for the proj- ect was very aggressive but the project team stayed together to overcome issues related to the mining of the tunnel," said Bob Huie, Project Director for the PC Rus- s t Risk ( or the project. The unique structure of the project team is credited with the overall project success despite challenges. "I'm proud of our team. They had obstacles and chal- lenges and challenging ground, but they stuck together and didn't give up, and they were successful. There was great leadership and supervision all around," said Larry Weslowski, Tunnel Superin- tendent for the PC Russell JV. The project is only the third such large construction project in the U.S. to use the e. The PC Construction/ HJ Russell JV was selecte for the project, who then purchased the R or the tunnel. The designer for the construction works including tunnel and shafts, JP2—con- sisting of Stantec, PRAD Group, Inc., and River 2 Tap—specified the hard ro Operation and assem then sub-contracted to the Atkinson/ Technique JV. The r embled using Onsite First Time Assembly (OFTA) at the massive Bellwood Quarry site with help from Robbins personnel. "The guys built everything per the specs to help with scheduling. It was a challenge but there was no negativity during the process," said Weslowski. Despite summer tem- peratures hitting 43 degrees Celsius (110 degrees Fahrenheit) and 100 percent hu- midity eady to launch by October 2016. Hard granitic rock challenged the 19- in. disc cutters from the outset. "There was ground so hard that it would take eight hours to go 1.5 m (5 ft). It was be- twe a (17,000 and 45,000 psi) UCS. The beginning of the job was tough," said Weslowski, but he add- ed that once the learning curve had been overcome "they started breaking project records left and right towards the end. We got a best day of 38.4 m (126 ft). Rates just kept increasing." Other challenges included groundwa- ter encountered during tunneling. "We did encounter groundwater contamina- tion that required remediation. This re- mediation work was completed success- fully," said Huie. With tunneling complete, the $300 million project for the City of Atlanta's Department of Watershe is on track to meet its scheduled overall completion date of September 2019. The project will turn the inactive Bellwood quarry into a 9.1 billion liter (2.4 billion gallon) raw water storage facility con- necting with the Chattahoochee River and various water treatment facilities. The Tunnelling Associa- tion of Canada (TAC) , the Canadian representative body of the International Tunnelling Association (ITA), announced its 2018 a . 8 as part of the 2018 TAC conference in Edmonton. The winners were: Lifetime Achievement Award: Garry Stevenson, Senior Geotechnical Engi- neer at Klohn Crippen Berger Ltd. Ste- venson has over 40 years of experience in soil and rock projects, including the design and construction of tunnels and shafts in a variety of ground condi- tions. He has authored several papers on dam and underground excavation design and construction. In addition to his lifetime of exemplary contributions to tunnelling engineering in Canada, . Stevenson served as TAC President from 2004 to 2008. Innovation Project of the Year: John Hart Generating Station Replacement Project. Infrastructure Project of the Year: Eglinton Crosstown LRT Tunnels. Dan Eis Pasquale Basso Trujillo. Pasquale is a Ph.D. candidate at Université Laval and is undertaking research on the structur- al performance of reinforced shotcrete structures, such as tunnel linings, and the safety of the works and its users. Tunnelling Association of Canada Announces 2018 Award Recipients 1 0 B U S I N E S S B R I E F S TUNNELINGONLINE.COM TBM: TUNNEL BUSINESS MAGAZINE // DECEMBER 2018 Robbins TBM Breaks Through on Atlanta Water Tunnel Project

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