Secant Pile Supported Underground Tank Binghamton-Johnson City Joint Sewage Treatment Plant Restoration and Rehabilitation Vestal, NY
The Binghamton-Johnson City Joint Sewage Treatment Plant Restoration and Rehabilitation Project was implemented after a catastrophic failure of one section of the plant which caused a release to the Susquehanna River in May 2011. Historic flooding of the plant in September 2011 during Tropical Storm Lee created additional repair challenges.
New construction includes a 96-ft wide by 192-ft long by 30-ft deep secant pile supported excavation for construction of a new Backwash Tank. The secant piles are 5-ft diameter and extend 36-45-ft below grade. Our secant pile design has a dual function. First as the temporary excavation support system and secondly as the foundation and exterior walls of the Backwash Tank.
During construction, the internal bracing of the secant pile wall consists of reinforced concrete wale beams and struts that are supported on caissons installed within the excavation footprint. The internal bracing and caissons will remain and become part of the permanent support element.
Brierley Associates was retained by GHD to: provide geotechnical and geo-structural feasibility analysis; design of the secant pile wall system and related support elements; design of permanent rock anchors to hold down the concrete base slab. Services included: completion of a supplemental subsurface investigation; preparation of a Geotechnical Data Report and Geotechnical Interpretative Report; preparation of design drawings and specifications for the secant piles, rock anchors and geotechnical instrumentation program. During construction, Brierley provided full-time resident engineering and inspection of secant pile and rock anchor installation.