REAME for Cylindrical Failure

Abstract

The REAME (Rotational Equilibrium Analysis of Multilayered Embankments) computer program can be used to determine the factor of safety of a slope based on a cylindrical failure surface (Huang, 1981b). A major advantage of REAME over other comparable computer programs is that it requires very little computer time to run. This is made possible by an efficient method of numbering the boundary lines for different soils and controlling the number of circles. This program is particularly useful to those who have very little experience in stability analysis. Without worrying about the computing cost, a large region can be searched, and the minimum factor of safety determined. Features of this program can be described briefly as follows: 1. Slopes of any configuration with a large number of different soil layers can be handled. 2. Seepage can be considered by specifying a piezometric surface or a pore pressure ratio. If necessary, several different seepage cases can be considered simultaneously to save the computer time. 3. Either the static or the seismic factors of safety can be computed. 4. Either the simplified Bishop method or the normal method can be used to determine the factor of safety. When the normal method is specified and the most critical circle is found, the factor of safety for this particular circle based on the simplified Bishop method is also printed. 5. More flexibility is allowed in radius control. One or more radius control zones can be set up, and the number of circles in each zone specified. 6. The factors of safety at a number of individual centers or at a group of centers, which form a grid, can be determined. By selecting one or more trial centers, a search routine can be activated to locate the minimum factor of safety. To obtain the minimum factor of safety in one run, the automatic search can follow immediately after the grid, using the most critical center obtained from the grid as the initial trial center for the search. 7. To preclude the formation of shallow circles, a minimum depth may be specified. Any circle having the tallest slice smaller than the minimum depth will not be run. 8. A cross section of the slope can be plotted by the printer, including all soil layers, the piezometric surface, and the most critical circle.