Critical acceleration versus static factor of safety in stability analysis of earth dams and embankments

The note is the result of computation of the critical acceleration factor kc and its use as a design parameter for earth dams in place of the static factor of safety. Kc is obtained as the first part of the solution towards the static factor of safety and is used as a measure of the latter. No iterative computations are required to obtain kc. In the kc method the curve for interstice body method is obtained by considering the stress conditions inside the mass. The usual method adopted in the design of earth dams and embankments involves finding the most critical surface and then finding the factor of safety for that surface. To do this the designer has to select hundreds of surfaces and compute factors of safety for each one of them. If kc can be used for the search pattern considerable time can be saved. A linear relation is found between static factor of safety F and kc. /TRRL/