Geologic controls of sand boil formation at Buck Chute, Mississippi

Abstract

Sand boil formation due to underseepage is a potential failure mechanism for levees in the Lower Mississippi River Valley. Sand boils were identified in the Buck Chute study area in the 1990s during high-water events and during the 2009 Flood. The site is unique due to the presence of point bar and abandoned channel deposits. To understand the role of these alluvial deposits on sand boil formation at the site, a geologic investigation of the subsurface was conducted. Using shallow geophysics, cone penetrometer tests (CPT), borings, and a geographic information system (GIS), researchers concluded that the thin blanket associated with point bar deposits, abandoned channel deposits causing a blocked seepage path, and head differential changes caused by the Muddy Bayou Control Structure were the controls of sand boil formation at Buck Chute. DISCLAIMER: The contents of this report are not to be used for advertising, publication, or promotional purposes. Citation of trade names does not constitute an official endorsement or approval of the use of such commercial products. All product names and trademarks cited are the property of their respective owners. The findings of this report are not to be construed as an official Department of the Army position unless so designated by other authorized documents.

A Sand Boil Database for Piping Risk Management in the Po River, Italy

“…Aerial/satellite imagery [21,22] is often used to detect morphological factors that may reveal the susceptibility to backward erosion piping of the river embankment system. Work by the U.S. Army Corps of Engineers (USACE) along the Mississippi River (e.g., [22,23]) found that point bar deposits-consisting of low ridges of silty sand/sand with intervening arcuate depressions (referred to as swales) filled with fine-grained sediments-and channel fill deposits are the primary geologic environments for sand boil formation. Swales and channel fill deposits indeed tend to confine, funnel or otherwise significantly affect the groundwater flow through the subsurface [18], thereby increasing the local pore water pressure.…”