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Introduction
Theoretical_Background
Method of Slices
Bishop
Spencer
Morgenstern & Price
Use of Limit Equilibrium
Choice of Geometry
Strengths & Pressures
Long Term Problems
Short Term Problems
Summary
References
Input Instructions
Geometry
Boundary Forces
Pore Pressures
Strength Parameters
Earthquake Loading
Iteration Control
M-P Method
Convergence
Examples
Example 1
Example 2
Example 3i
Example 3ii
Example 4
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Slopes often appear to fail on circular slip surfaces and it is often reasonable to analyze slope stability using circular slip surfaces. However, there are also many instances when this is not the case. Non-circular slip surfaces may be more critical than circular slip surfaces when:
There is a weak layer present in the foundation. The weak layer could be a soft clay (Leonards, 1982; Fredlund et al., 1981) or a liquefiable sand (Seed and Wilson, 1967).
There is a heavily overconsolidated, stiff fissured-clay or clay-shale foundation for an embankment. These materials tend to have highly anisotropic shear strength in which the strength may be as little as twenty percent along fissures as compared to other directions (Wright and Duncan, 1972; Duncan and Dunlop, 1969).
A dam's core is sloping and is significantly weaker than its shell. (For illustration, see Example 1 for TSLOPE.)
There are some slopes where three dimensional effects make an important contribution to stability. For these cases TSLOPE3 should be used.