Investigations of pile foundations in Brownfields

'Brownfields' are real estate properties with subsurface or surface contamination. The redevelopment of Brownfields is required to clean, improve, and protect the environment. Pile foundations are often used in Brownfields and other contaminated site situations to support structures. Regulators are concerned about the environmental safety of pile foundations in Brownfields sites, since piling in Brownfields may lead to transport of contaminants from the contaminated region to underground aquifers. This investigation is an extension of previous research programs on pile foundations in Brownfields or contaminated sites conducted at the University of New Orleans. The purpose of the overall investigation is to evaluate the potential for contaminant transport due to pile foundations in Brownfields. The current paper summarizes the research carried out to ascertain the potential for contaminant transport from concrete piles of different shape, depth of penetration, and method of installation. The results of bench scale model tests and numerical studies are presented. Under full penetration conditions, the square shaped and circular cast-in-place piles were found to have a higher potential for contaminant transport than circular driven piles. There is a low potential for contaminant transport in the case of piles penetrating less than 95% of an aquitard. Selected results from a previous program on wooden and steel piles are summarized for comparison. CE Database subject headings: Pile foundations; Soil pollution; Environmental issues; Groundwater pollution; Aquifers.