Slope Stability Analysis by Swedish Slip Circle Method Using C-Programming

Shweta S. Pande; Shubhada S. Koranne, Dipak Kumar Mishra

Abstract

The side slopes of an earthen dam should be safe against shear failure. Out of the various methods of stabilityanalysis of slopes, “Swedish Slip Circle Method” is commonly used in practice. Here in the Swedish circlemethod, potential failure surface is assumed to be cylindrical in shape (i.e., circular in cross section). Afterdetermining the actuating and resisting forces for assumed failure surface, the factor of safety is calculated. Theslope is considered safe if the minimum factor of safety is greater than the specified value. This paper aims atpresenting the procedure for determination of factor of safety using C-program. The program helps to calculatenormal component (N) and tangential component (T) at a faster rate as compared to graphical method. With theuse of co-ordinate system for determination of normal and tangential components, the program results in a veryaccurate value which will otherwise be approximate, if calculated by graphical method. The program alsodisplays N-plot, T-plot and U-plot which are important features of rectangular plot method. Another importantfeature of the program is the graphical representation of cross section of the dam along with assumed slipsurface and number of slices with different forces acting on them. This paper aims at comparing the value offactor of safety obtained by graphical method with that obtained by C-program. With this computationalapproach, the obtained factor of safety is more accurate than that obtained by conventional graphical method.Keywords: N-plot and T-plot, factor of safety, rectangular plot method, normal and tangential components,slope stability, graphical method