b'PASSENGER TRANSPORTATL 47ATLNext program staff report that greatOnce the tunnel was fully excavated and strides have been made in the $266 millionaligned, Wael Darwish of WSP USA took Plane Train Tunnel West Extension Project,over to oversee design and construction of which will lengthen the existing people moverthe Plane Train Tunnel West Extension. system with a 600-foot tail track. David Pino,In total, the project contains seven design an H.J. Russell & Company project managerpackages, including one in the terminal, one who is augmenting Department of Aviation staffin the tunnel itself, one for the shaft, and one as area director for the tunnel extension, notesDAVID PINO for the bifurcation area, among others. WAEL DARWISHthat the ATLNext Project Team recognized very early on that the extension was an unusual project.By January 2020, the project team hit another major milestone when it completed construction of the Plane Train shaft. Work It was quickly determined that tunneling expertise wouldcontinued despite the COVID pandemic, and there were few be a hard and fast requirement for eligible contractors vyingdesign changes until June 2021, when the team made minor to complete the first western extension of the Plane Trainrevisions to the projects seven design packages. system that was originally built in the 1980s. Given the design complexities, the team also opted to approach the project with aPrice Checkprogressive design-build contract when the project first enteredThe ongoing tunnel expansion is being executed in phases that pre-construction and pre-design stages in August 2018. have been contracted via Component Guaranteed Maximum Price It was the first time that the Department of Aviation hasTask Orders. Pino notes that September 2022 was a noteworthy ever done a progressive design-build, Pino notes, adding thatpoint in the process because that was when the team was able to the team worked with the citys legal department and outsidecome to a guaranteed maximum price for the construction of the counsel to write the final contract before putting it out to bid.entire project.The Request for Proposals clearly specified that candidatesLooking ahead, Darwish is pleased that the end date for the needed contracting, design and tunneling experience. Ultimately,civil engineering portion of the $266 million progressive design-the winning bids included tunnel designer McMillen Jacobsbuild turnback project is just around the corner in spring. The Associates (now Delve Underground) and design-build joint venture Clark Construction-Atkinson-Technique.Digging and BlastingEnabling work to accommodate the tunneling activity began in June 2019. The elevator at Bag Claim station was right at the end of the (north) tunnel, so we had to move it out of the way in order to extend the tunnel, relates Pino.Once that elevator and all other obstacles were removed, the challenge of mixed-face tunneling commenced, with crews mainly working from 10 p.m. to 3 a.m. when the train station that serves the Bag Claim area is closed. Dealing with a combination of materials required tunneling crews to use multiple strategies, including a micro-bench cut method to excavate the softer ground in small sections.A lot of the tunnel had mixed face, with some dirt and some rock, Pino explains. And the rock profile gradually changed the closer we got to the terminal.When crews began to encounter solid rock, controlledblasting began. PLANNING FOR SUCCESSFrom optimizing runways to enhancing passenger experiences, Under the terminal, we had about 200 blasting eventswe are trusted pioneers in airport master planning.throughout the process, mostly at night, Pino reports. Contractors used vibration and noise monitors to assess the aboveground effects and ensure that airport occupants wouldnt mistake their work for an earthquake. All of that went very well, Pino recalls.1-888-AVCON-99 See how AVCON puts www.avconinc.com the pieces together.AirportImprovement.comJanuary | February 2024'