Applications of 3D slope stability analysis

As might be expected from a method nearly a century old, the use of 2D slope stability analysis using the method of slices is commonplace. Computer codes have existed for over-4 decades. Three-dimensional analysis, by a method of columns, is much rarer, not least because the computer codes are not widely available. Furthermore, some writers appear to be of the opinion that 3D computations always give Factors of Safety larger than 2D methods, making the latter conservative. This paper discusses, with examples, some of the applications of 3D slope stability analyses, with practical advice as to when the full 3D analysis may safety be dispensed with.