Application of two new stereographic projection techniques to slope stability problems

• This study involves two new stereographic projection methods.
• This study examines the effects of explicitly the foliations in the slope stability analysis.
• The comparison of the kinematic analysis and the observed slope movements.
• The direction-lines obtained by converting the planar-elements to the linear-elements on the net.
• The relationships between the discontinuities and tension cracks on the berms were examined.

Slope instabilities were observed in the benches of the Alipaşa open pit albite mine in the Menderes Massif forming one of the tectonic zones of the Anatolides in Turkey. Tension crack patterns observed in the berms were formed depending on the discontinuity planes cutting each other in the orthogneiss rock unit. Two new stereographic projection methods in the stability analyses were applied by considering two cases; the first one that used the overlay linear-element process based on the geometrical conditions relating to the ground movement directions on the survey monuments, dip direction-lines of the foliation planes and sloped bench faces, and the second one that based on the determination of relationships between tension cracks on the upper slope face and discontinuity sets into the slope forming release and lower surfaces of the sliding blocks. It is kinematicly investigated with the overlay linear-element process whether an agreement among these parameters is presence or not. If there is, this case is indicated that the planar sliding was occurred on the foliation plane beforehand, or in a critical balance in terms of the planar-sliding of a slope. The proposed method will be useful to determine quickly and efficiently whether the relationships between the discontinuity sets into the rock masses and tension cracks on the berms or upper slope faces in an open pit or not. In addition, whether the angular values from the kinematic analysis are in agreement with the ones directly measured from the field was also investigated. This study involved making stability assessment of the already failed and standing sloped bench faces in the open pit using the stereographic projection techniques and software.