Graphical Stability Analysis of Slopes in Jointed Rock

Abstract

Graphic projections on a reference hemisphere, using either stereo nets or equal-area nets, are utilized in geologic analyses. The same graphic concept can be used in practical engineering evaluations of the stability of slopes affected by a three-dimensional but planar geologic structure. The effects of remedial measures can also be evaluated. The elements of hemispheric projections such as equatorial nets, meridional nets, pole diagrams, great circles, small circles, friction cones etc. are illustrated on both equal-area nets and spatial views. An example shows the use of these elements in both geologic and engineering phases of a slope stability study. Both wedge-type slides along two planes and block-type movements on one plane with the opening of the other planes are considered. Blanks forms of the three nets used are included.