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2017SpringShotcreteEMag

Fig. 11: Finished access Tunnel 1 arch with rubber float finish Fig. 13: Pump location at intersection of 37th and Park in New York, NY, for the placements in upper-level arch of TT#1 structure than 72 hours before they are required. Large equipment is needed at least a week in advance. The general access for the workers on this project was also limited on the project. The general access was from street level near 48th and Madison in Manhattan. Some of the work locations underground were as far south as 37th Street and Park Avenue. The workers could not travel within the tunnels until the work day commenced, and thus required up to an additional 30 minutes of the work day spent in the morning for them to access the tunnel level via elevator (Alimak) and then walk to the day’s work locations. This process was repeated at the end of the work day so that all workers would be out of the tunnel before the shift was over. Over the course of the project, the use of shotcrete placement for structural concrete sections significantly increased. Superior Gunite shotcreted structural concrete in nearly every structure on the projects, including the running tunnels, cross passages, cavern walls, and arches. The use of shotcrete significantly benefited the Michels Corporation schedule and costs by reducing the formwork required and adding flexibility to the project. At the completion of the project in March 2016, Superior Gunite installed over 14,000 yd3 (11,000 m3) of shotcrete throughout. Frank E. Townsend III is the East Coast Region Manager for Superior Gunite. He received his degree in civil engineering from Worcester Polytechnic Institute and his master’s degree from the University of Missouri. Townsend comes from the U.S. Army Corps of Engineers and his diverse military background has led to him being deployed around the world. Townsend is an active member of ACI Committee 506, Shotcreting, and a Board member of ASA. He has been Awarded the U.S. Army Corps of Engineers deFluery Medal and the Engineer News-Record New York’s “Top 20 under 40” award for design and construction leaders in 2016. Fig. 12: Finished GCT 1/2 arch with rod finish. Walls were rubber float finished pump located in the underground caverns for the final delivery and shotcrete placement. Due to the volume of material in the slick line and the slower nature of shotcrete placements, the concrete used a conventional retarding admixture to prevent the material from setting up in the slick line. WORKER AND MATERIAL LOGISTICS Unlike most typical tunneling projects that use multiple shafts along the tunnel length for the access of workers and materials, the East Side Access Project is unique, as the only material access is 7 miles (11 km) away in Long Island City. Here, the materials are loaded onto work trains and brought into the project on a designated schedule. This one point of access, in conjunction with the use of work trains, introduces an immediate 24-hour delay from when the materials arrive in the project yard to when they are available at the work location. Supply delays are further increased at peak project production times as availability of space on the working trains is quickly taken with the deliveries of steel, waterproofing, and equipment. As a result, materials need to be scheduled and delivered to the access point no less www.shotcrete.org Spring 2017 | Shotcrete 15


2017SpringShotcreteEMag
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