GZA GeoEnvironmental, Inc. reposted this
Congratulations to GZA GeoEnvironmental, Inc. for earning a PDCA Project of the Year Award in the Associate/Engineering Affiliate category! The Back Cove West Storage Conduit project surpassed the conventional scope of buried pipe installations by using an innovative driven sheet piling support of excavation to overcome complex challenges – difficult site conditions, sensitive marine clay and custom-built equipment – with ingenuity and expertise. The project: a pre-cast concrete storage conduit providing a storage capacity of approximately 2.25 million gallons. Sargent Corporation was awarded the work and retained GZA GeoEnvironmental, Inc. to provide engineering support during construction. In the initial project phases, Sargent worked closely with Wright-Pierce to value engineer the storage conduit design. Departing from the original plan, which entailed a linear trench excavation spanning 3,800 feet for a single box conduit, Sargent proposed an alternative approach: employing a 1,700-foot-long double box conduit configuration with identical storage volume. This strategic revision not only halved the length of the excavation and significantly reduced the volume rock to be excavated, but also yielded substantial cost savings of approximately $1 million while expediting the project timeline. To address unique excavation requirements, Sargent enlisted the expertise of GZA to devise a tailored support of excavation (SOE) design. GZA and Sargent evaluated SOE options. The project specifications presented a range of potential support systems including driven sheet piles, drilled soldier piles and lagging, and trench boxes, provided they adhered to best practice standards. Prohibitive drilling expenses and apprehensions regarding groundwater infiltration eliminated drilled soldier piles and lagging as an effective solution. Although the off-the-shelf trench boxes were a viable option, operational constraints arose in accommodating the gantry crane. Hence, the selection of driven sheet piles and internal bracing was deemed the most advantageous and cost-effective SOE system. Driven sheet piles offered several notable benefits, including ready availability, easy installation and, crucially, the ability to be removed and reused. Read about the project in the Project of the Year edition of #PileDriverMagazine: https://lnkd.in/g8qSP2HX #PDCADriven #piledriving #earthretention #steelsheetpiles #supportofexcavation #valueengineering