Buoyancy is a critical factor for every underground precast concrete structure design plan.
The sheer weight of precast concrete offers an advantage over lighter materials. But even though precast structures rest firmly in excavations, the product’s buoyancy must be considered and factored within the design process.
A faulty buoyancy calculation can result in floating or a product shifting upward. To help precast concrete product manufacturers better understand buoyancy and make these calculations, NPCA recently updated its Buoyancy White Paper, which outlines the process in detail. The August 2022 revision better enhances sample calculations, extends definitions of terms and clarifies equations throughout the paper.
Written and edited by current and former NPCA engineers – Daryl Burns, P.E.; Eric Carleton, P.E.; Phil Cutler, P.E.; Claude Goguen, P.E., LEED AP; and Kayla Hanson, P.E. – this guide is available for free on NPCA’s website here.
The NPCA Buoyancy White Paper also is supplemented by a buoyancy calculator for both rectangular and round structures. This calculator is Excel-based and provides easy-to-use calculation menus for both rectangular and round structures.
Read the white paper here.
Access the calculator here.
If you have any questions, contact Chris Frederick at firstname.lastname@example.org or (800) 366-7731.