Details:

Creators:
Vitton, Stanley ; Williams, Alexander
Vitton, Stanley ; Williams, Alexander Less -
Corporate Creators:
Michigan Technological University. Department of Civil and Environmental Engineering
Corporate Contributors:
Michigan Tech Transportation Institute
Subject/TRT Terms:
[+]
Cliffs Cliffs--Erosion--Michigan Erosion Soil Erosion--Michigan Soil Erosion Prediction--Michigan Soils
Publication/ Report Number:
RC-1526
Resource Type:
Tech Report
Geographical Coverage:
Michigan
Edition:
Final report.
Corporate Publisher:
Michigan. Dept. of Transportation. Construction and Technology Division. Testing and Research Section
Abstract:
A section of highway US-41 seven miles north of Baraga, MI runs along a 100 foot high cliff overlooking Keweenaw

Bay. Since construction of the highway, cliff recession has advanced to a point where it is allowing the undercutting of

the guardrail system of the highway and threatening the highway’s overall stability. A research program was

conducted to determine the cliff’s recession rate and if the highway should be relocated. The analysis included

investigating variations in shore platform widths, environmental factors, and rock characteristics. Laboratory testing of

the cliff rock included point load testing and uniaxial compressive testing, while the rock quality designation (RQD)

and rock mass rating (RMR) were determined from the rock core drilling. Factors affecting the rate of cliff recession

are: (1) rock weathering and water migration from surface water as well as from water flowing above low permeability

layers within the cliff face rock; (2) removal of weathered cliff talus material at the base of the cliff by long shore

currents and wave action; and (3) the long term development of a stable talus slope at the base of the cliff. It was

found that the average cliff recession rate was between 0.15 and 1.5 inches per year but that various sections of the cliff

were regressing at a faster rate due to more localized factors. Survey data of the stable slopes to the south of the cliff

indicate that stable slopes develop at between 30° and 33° slopes. It is likely that the Baraga Cliffs will naturally

evolve to this slope angle similar to the slopes to the south of the cliffs. It is recommended that the highway be

relocated to a position beyond where a stable slope will develop. This recommendation, however, is premised on a

stable talus slope forming and successful vegetation developing on the slope. This also assumes that the lake levels

remain at their current level or near the long term lake average.


Format:
PDF
Funding:
2006-0414
Collection(s):
US Transportation Collection
Main Document Checksum:
[+]
urn:sha256:b862994ac66d169a391c0da4f9a1220c1115b0000034221e9c7238ebb837d5d2
Download URL:
https://rosap.ntl.bts.gov/view/dot/18192/dot_18192_DS1.pdf
File Type:

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