Date of Award
Master of Science
Geological and Environmental Sciences
Dr. Ron Chase
Dr. Alan Kehew
Dr. Duane Hampton
Masters Thesis-Open Access
Bluff failure along the Lake Michigan coast can be produced primarily by increased pore pressure from perched water tables above lacustrine clay deposits. To test this theory, a site in Allegan County, Michigan with alternating layers of sand, clay and glacial till was chosen for bluff failure monitoring. Historically, the site experiences sporadic massive failures as opposed to neighboring sites that show more regular and uniform displacements. Four pole and cable monitoring lines were measured bi-weekly from December 2001 to October 2003. Lake levels were low and no erosion of material at the base of the slope occurred. Slumps above shallow shear planes were observed during the winter and spring seasons. Limit equilibrium analyses, replicating both pore pressure fluctuations and wave cutting, suggests that increased pore pressure is the dominant factor associated with the movement. The periodic massive failures appear to be controlled largely by a combination of intermittent, voluminous groundwater infiltration and by the large volume of weak, unconsolidated sand in the lower portion of the stratigraphic section.
Young, "Slope Stability Analysis of a Lake Michigan Coastal Bluff" (2004). Master's Theses. 3922.