- Email: [email protected]
Stability analysis of deep slides in brittle soil — lessons from Carsington
320A sliding of the cover layer are examined. Effects of permeability of the structural components on stability and the difficulties in estimating permeabilities are discussed.
Slopes
failure, for which history and geometry are well documented. The method cannot deal with progressive failure in 2 dimensions for a brittle soil which shows post peak softening, or with progressive failure due to lateral load transfer in 3 dimensions, or lateral load transfer after a slide such that residual strength cannot be deduced from backanalysis. Analyses for these cases are presented.
See also: 925008, 925083, 925084, 925196, 925228, 925283 925363 Atlas of rock engineering mechanisms. Part 2 - slopes. Technical note Hudson, J A
lnt J Rock Mecb Min Sci V29, N2, March 1992, P157-159 A second atlas of rock engineering mechanisms is presented to complement that published earlier for underground excavations. The purpose is to illustrate the linkage between basic slope features and the rock mechanics and rock engineering mechanisms which may relate to the slopes. This is achieved using an interaction matrix, with main factors placed in the leading diagonal and off-diagonal boxes indicating coupling effects of primary factors. The matrix is not complete, in that additional terms might be added to the leading diagonal. It does however form a useful checklist of mechanisms and with development can become a basic tool for slope engineering. 925364 Mapping slope failure potential using fuzzy sets Juang, C H; Lee, D H; Sheu, C
J Geotech Engng Div ASCE Vl18, N3, March 1992, P475494 An economic, qualitative analysis scheme for mapping slope failure potential (SFP) using fuzzy set analysis is presented. Four categories of factors affecting stability are considered: geology, topography, meteorology, and environment. Each contains 2 to 5 factors, and a total of 13 factors in all is used. Evaluation criteria are established for each adopted factor. Analysis or computation involving fuzzy sets was performed using Monte Carlo simulation. A SFP index to measure slope failure potential is defined. A SFP map of Mount So-San, Taiwan, is prepared, which appears to correctly predict failure potential of the study area. 925365 Rain-induced slope failures caused by reduction in soil strength. Technical note Yoshida, Y; Kuwano, J; Kuwano, R
925367 Tension cracks and slope failure Chowdhury, R N; 7hang, S
Proc Conference on Slope Stability Engineering: Developments and Applications, Isle of Wight, 15-18 April 1991 P27-32. Publ London. Thomas Telford. 1991 The geomechanics model for slope stability analysis must be realistic. The existence of tension cracks, which reduce the length of potential slip surfaces over which resistance can be mobilised and may fill with water and exert an additional driving force, must be taken into account in cohesive soils. An approach based on assumption of the depth of tension cracks from interslice forces in any limit equilibrium method of slices is presented. The general Janbu method is modified and combined with an approach involving the Simplex Reflection Method. The presence of tension cracks in slopes is shown to significantly lower safety factors.
925368 Observation of Graben geometry in landslides Cruden, D M; Thompson, S; Hoffman, B A
Proc Conference on Slope Stability Engineering: Developments and Applications, Isle of Wight, 15-18 April 1991 P33-35. Publ London." Thomas Telford, 1991 Where slide movement is principally translational, displaced material at the head usually subsides to form a graben. Geometric data from such grabens from slides on poorly indurated, flat lying sedimentary rocks have been collected in Alberta. A simple mechanical model for the processes involved is developed. Observations indicate depth from ground surface to rupture surface is about 1.1 times initial graben width. Predictions of this ratio from the model developed show considerable scatter, indicating that complicating factors influence the simple mechanics assumed.
Soils Found V31. N4, Dec 1991, P187-193 Shallow depth failures triggered by heavy rainfall were investigated at 4 sites in Japan. Slope angles were 30-45 deg, and soils varied from sandy to silty. Soil samples were taken for laboratory strength characterisation. Decreasing strength with increasing degree of saturation was seen. Slope stability analyses showed factors of safety similarly decreasing with increasing saturation, values of unity being reached at saturation ratios of 60-90%. 925366 Stability analysis of deep slides in brittle soil - lessons from Carsington Vaughan, P R
Proc Conference on Slope Stability Engineering: Developments and Applications, Isle of Wight, 15-18 April 1991 PI-II. Publ London: Thomas Telford, 1991 Limit equilibrium analysis in two dimensions is generally used to analyse slope stability. The shortcomings of this approach are examined with particular reference to the Carsington Dam
925369 Calculation procedures for slope stability analyses involving negative pore-water pressures Rahardjo, H; Fredlund, D G
Proe Conference on Slope Stability Engineering: Developments and Applications, Isle of Wight, 15-18 April 1991 P43-49. Publ London: Thomas Telford, 1991 Two dimensional limit equilibrium methods of slices are commonly used in slope analysis because of their proven record where pore pressures and soil properties are well characterised and their limited input data requirement. The effects of matric suction on shear strength of soils have become better understood in recent years and methods to incorporate them into slope stability analysis are proposed. Factors of safety are derived with respect to force and moment equilibria. Pore water designation in terms of pore pressure coefficients, pore pressure head contours, or piezometrie lines is possible. An example analysis is presented.
© 1992 Pergamon Press Ltd. Reproduction not permitted
Slopes
failure, for which history and geometry are well documented. The method cannot deal with progressive failure in 2 dimensions for a brittle soil which shows post peak softening, or with progressive failure due to lateral load transfer in 3 dimensions, or lateral load transfer after a slide such that residual strength cannot be deduced from backanalysis. Analyses for these cases are presented.
See also: 925008, 925083, 925084, 925196, 925228, 925283 925363 Atlas of rock engineering mechanisms. Part 2 - slopes. Technical note Hudson, J A
lnt J Rock Mecb Min Sci V29, N2, March 1992, P157-159 A second atlas of rock engineering mechanisms is presented to complement that published earlier for underground excavations. The purpose is to illustrate the linkage between basic slope features and the rock mechanics and rock engineering mechanisms which may relate to the slopes. This is achieved using an interaction matrix, with main factors placed in the leading diagonal and off-diagonal boxes indicating coupling effects of primary factors. The matrix is not complete, in that additional terms might be added to the leading diagonal. It does however form a useful checklist of mechanisms and with development can become a basic tool for slope engineering. 925364 Mapping slope failure potential using fuzzy sets Juang, C H; Lee, D H; Sheu, C
J Geotech Engng Div ASCE Vl18, N3, March 1992, P475494 An economic, qualitative analysis scheme for mapping slope failure potential (SFP) using fuzzy set analysis is presented. Four categories of factors affecting stability are considered: geology, topography, meteorology, and environment. Each contains 2 to 5 factors, and a total of 13 factors in all is used. Evaluation criteria are established for each adopted factor. Analysis or computation involving fuzzy sets was performed using Monte Carlo simulation. A SFP index to measure slope failure potential is defined. A SFP map of Mount So-San, Taiwan, is prepared, which appears to correctly predict failure potential of the study area. 925365 Rain-induced slope failures caused by reduction in soil strength. Technical note Yoshida, Y; Kuwano, J; Kuwano, R
925367 Tension cracks and slope failure Chowdhury, R N; 7hang, S
Proc Conference on Slope Stability Engineering: Developments and Applications, Isle of Wight, 15-18 April 1991 P27-32. Publ London. Thomas Telford. 1991 The geomechanics model for slope stability analysis must be realistic. The existence of tension cracks, which reduce the length of potential slip surfaces over which resistance can be mobilised and may fill with water and exert an additional driving force, must be taken into account in cohesive soils. An approach based on assumption of the depth of tension cracks from interslice forces in any limit equilibrium method of slices is presented. The general Janbu method is modified and combined with an approach involving the Simplex Reflection Method. The presence of tension cracks in slopes is shown to significantly lower safety factors.
925368 Observation of Graben geometry in landslides Cruden, D M; Thompson, S; Hoffman, B A
Proc Conference on Slope Stability Engineering: Developments and Applications, Isle of Wight, 15-18 April 1991 P33-35. Publ London." Thomas Telford, 1991 Where slide movement is principally translational, displaced material at the head usually subsides to form a graben. Geometric data from such grabens from slides on poorly indurated, flat lying sedimentary rocks have been collected in Alberta. A simple mechanical model for the processes involved is developed. Observations indicate depth from ground surface to rupture surface is about 1.1 times initial graben width. Predictions of this ratio from the model developed show considerable scatter, indicating that complicating factors influence the simple mechanics assumed.
Soils Found V31. N4, Dec 1991, P187-193 Shallow depth failures triggered by heavy rainfall were investigated at 4 sites in Japan. Slope angles were 30-45 deg, and soils varied from sandy to silty. Soil samples were taken for laboratory strength characterisation. Decreasing strength with increasing degree of saturation was seen. Slope stability analyses showed factors of safety similarly decreasing with increasing saturation, values of unity being reached at saturation ratios of 60-90%. 925366 Stability analysis of deep slides in brittle soil - lessons from Carsington Vaughan, P R
Proc Conference on Slope Stability Engineering: Developments and Applications, Isle of Wight, 15-18 April 1991 PI-II. Publ London: Thomas Telford, 1991 Limit equilibrium analysis in two dimensions is generally used to analyse slope stability. The shortcomings of this approach are examined with particular reference to the Carsington Dam
925369 Calculation procedures for slope stability analyses involving negative pore-water pressures Rahardjo, H; Fredlund, D G
Proe Conference on Slope Stability Engineering: Developments and Applications, Isle of Wight, 15-18 April 1991 P43-49. Publ London: Thomas Telford, 1991 Two dimensional limit equilibrium methods of slices are commonly used in slope analysis because of their proven record where pore pressures and soil properties are well characterised and their limited input data requirement. The effects of matric suction on shear strength of soils have become better understood in recent years and methods to incorporate them into slope stability analysis are proposed. Factors of safety are derived with respect to force and moment equilibria. Pore water designation in terms of pore pressure coefficients, pore pressure head contours, or piezometrie lines is possible. An example analysis is presented.
© 1992 Pergamon Press Ltd. Reproduction not permitted