Some notes on the upper-bound and Sarma’s methods with inclined slices for stability analysis
Z.Y. Chen · 2008
S. K. Sarma assumes that limit equilibrium conditions prevail on both the base and interfaces and solve the factor of safety by the force equilibrium conditions. This chapter provides some further examples demonstrating its accuracies and discusses two issues involved in the use of the upper-bound or Sarma’s method: the requirement for identifying alternative directions of relative movement between two contiguous slices; treatments when tension occurs in the calculations. In addition to its elegant analytical formulations, the method enjoys a sound theoretical background supported by the upper-bound theory of Plasticity. A series of testing problems has demonstrated its ability of producing closedform solutions provided by the slip-line field method using its numerical procedures. The chapter examines an example demonstrating that the controlling equation of the upper-bound method proposed by Donald and Chen is reducible to that provided by the classical slip-line field method.