Accession Number : ADA187240

Title :   An Examination of Slope Stability Computation Procedures for Sudden Drawdown.

Descriptive Note : Final rept.,

Corporate Author : ARMY ENGINEER WATERWAYS EXPERIMENT STATION VICKSBURG MS GEOTECHNICAL LAB

Personal Author(s) : Wright, Stephen G ; Duncan, J M

PDF Url : ADA187240

Report Date : Sep 1987

Pagination or Media Count : 177

Abstract : 'Sudden' or 'rapid' drawdown is considered to occur when reservoir or other adjacent water levels are lowered at such a rate that little or no drainage occurs in an earth slope at the time the water level is being lowered. Slope stability analyses are routinely performed to calculate the factor of safety for earth slopes subjected to this condition. This study provides a basis for a number of important conclusions regarding the accuracy and the degree of conservatism of the procedures for analyzing rapid drawdown slope stability. The best procedure should have the following characteristics: a. The procedure should employ a measure of shear strength and pore pressure that reflects the actual properties of the soils in the slopes. b. The procedures should use a soundly bases technique for relating shear strength to effective consolidation pressures. and c. The procedure should not include strength components due to to negative pore water pressures to avoid overestimating factors of safety for conditions where partial drainage occurs during drawdown. A method with these characteristics can be conceived as a combination of methods currently in use. Keywords: Effective stress analysis; Pore pressure coefficients; Shear strength envelopes.

Descriptors :   *SOIL MECHANICS, ACCURACY, SLOPE, SAFETY, SHEAR STRENGTH, DRAINAGE, COEFFICIENTS, PORE PRESSURE, WATER, SOILS, SOIL MODELS, WATER TABLE, STRENGTH(GENERAL), STRESS ANALYSIS, STABILITY, COMPUTATIONS

Subject Categories : Soil Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE