Residual shear strength mobilized in Red River slope failures

Mesri G., Huvaj Sarıhan N.

9th International Symposium on Landslides (9th ISL), Rio De Janeiro, Brazil, 28 June - 02 July 2004, vol.2, pp.925-931

  • Publication Type: Conference Paper / Full Text
  • Volume: 2
  • City: Rio De Janeiro
  • Country: Brazil
  • Page Numbers: pp.925-931


The Red River, which separates Grand Forks, North Dakota, from East Grand Forks, Minnesota,
floods its banks in the spring or early summer as a result of spring rains and snow melt. To assess the
stability of Red River slopes and to evaluate alternative flood control measures, the St. Paul District of the
United States Army Corps of Engineers and the City of Grand Forks have conducted detailed subsurface investigations
and field observations, including sampling and laboratory testing, and field measurements of
groundwater levels and ground movements. Slope stability analyses were carried out for six locations to
evaluate the residual shear strength mobilized for reactivated and first-time slope movements. The backcalculated
residual friction angles for the Lake Agassiz Brenna clay, with a liquidity index in the range of 0.3
to 0.6, are consistent with those from laboratory tests, and from empirical correlations for stiff clays and