1 Slope Stability Failure Planes or Slip Surfaces Text section 14.9 and only. - ppt download
By A Mystery Man Writer
Description
3 Slope Stability In slope stability analysis we determine the Factor of Safety as a ratio of resisting forces to driving forces F s = Resisting / Driving Theoretically, any slope with a Factor of Safety less than one will fail and any slope with a factor of safety greater than one will not. Design focuses on the soil parameters and geometry that will provide the maximum factor of safety. Sometimes, the analysis of an existing slope will be what is called a parametric study – that is establishing a factor of safety and performing an analysis that back calculates the strength parameters. The engineer will then determine his/her confidence level as to whether or not the soil has that strength through experience, lab, and/or field data.
1 Slope Stability Failure Planes or Slip Surfaces Text section 14.9 and only
2 Slope Stability In general you have: Driving Force – Weight of Slope Resisting Force – Strength of soil along slip surface Buttress at toe W c
Design focuses on the soil parameters and geometry that will provide the maximum factor of safety. Sometimes, the analysis of an existing slope will be what is called a parametric study – that is establishing a factor of safety and performing an analysis that back calculates the strength parameters. The engineer will then determine his/her confidence level as to whether or not the soil has that strength through experience, lab, and/or field data..
4 Slope Stability Example of Circular Slip Surface (from geoslope software) Circular slip surfaces often used in analysis as the most likely approximated shape of the failure surface
5 Slope Stability Non circular slip surfaces can also be analyzed
Now: W n sin α (driving) N= W n cos α T r = shear face = c’ + F ’ tan φ’ (resisting) W n sinα W n cos α α.
7 Slope Stability Performing this analysis on each slice and then summing the components from each slice F s = Σ (c L + W cos α tan φ) / Σ (W sin α )
8 Slope Stability This analysis is very conducive to a tabular solution WedgecφαLWW sin αc LW cos α tanφ8 + 9 F s = Σ (10) / Σ (7)
9 Slope Stability - Example Each box is 5’ x 5’ * = 120 pcf c = 300 psf φ = 32 o
10 Slope Stability - Example First, Find the areas for each slice A1 A2 A3 A4
11 Slope Stability WedgecφαLWW sin αc LW cos α tanφ F s = Σ (10) / Σ (7)
1 Slope Stability Failure Planes or Slip Surfaces Text section 14.9 and only
2 Slope Stability In general you have: Driving Force – Weight of Slope Resisting Force – Strength of soil along slip surface Buttress at toe W c
Design focuses on the soil parameters and geometry that will provide the maximum factor of safety. Sometimes, the analysis of an existing slope will be what is called a parametric study – that is establishing a factor of safety and performing an analysis that back calculates the strength parameters. The engineer will then determine his/her confidence level as to whether or not the soil has that strength through experience, lab, and/or field data..
4 Slope Stability Example of Circular Slip Surface (from geoslope software) Circular slip surfaces often used in analysis as the most likely approximated shape of the failure surface
5 Slope Stability Non circular slip surfaces can also be analyzed
Now: W n sin α (driving) N= W n cos α T r = shear face = c’ + F ’ tan φ’ (resisting) W n sinα W n cos α α.
7 Slope Stability Performing this analysis on each slice and then summing the components from each slice F s = Σ (c L + W cos α tan φ) / Σ (W sin α )
8 Slope Stability This analysis is very conducive to a tabular solution WedgecφαLWW sin αc LW cos α tanφ8 + 9 F s = Σ (10) / Σ (7)
9 Slope Stability - Example Each box is 5’ x 5’ * = 120 pcf c = 300 psf φ = 32 o
10 Slope Stability - Example First, Find the areas for each slice A1 A2 A3 A4
11 Slope Stability WedgecφαLWW sin αc LW cos α tanφ F s = Σ (10) / Σ (7)
1 Slope Stability Failure Planes or Slip Surfaces Text section
Slope stability - Wikiwand
15.1 Factors That Control Slope Stability – Physical Geology – 2nd Edition
Factor of Safety-Soil Mechanics and Foundations-Lecture 37 Slides2-Civil and Environmental Engineering, Lecture notes Soil Mechanics and Foundations
Ch10-Slope Stability Examples, PDF, Soil Mechanics
Blog — McLindon Geosciences, LLC
Slope stability
Why Are There Agulhas Rings? in: Journal of Physical Oceanography Volume 29 Issue 4 (1999)
Earth Slope and Slip Failures
Hydrogeologic characterization of Area B, Fort Detrick, Maryland
A practical procedure for the back analysis of slope failures in closely jointed rock masses - ScienceDirect
from
per adult (price varies by group size)