Date of Award

12-2004

Degree Name

Master of Science

Department

Geosciences

First Advisor

Dr. Ron Chase

Second Advisor

Dr. Alan Kehew

Third Advisor

Dr. Duane Hampton

Access Setting

Masters Thesis-Open Access

Abstract

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.

Included in

Geology Commons

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