Analyse multicritère des mouvements gravitaires dans la région est de la willaya de Bejaia (Cas : cap Aokas)

Abstract

This paper is devoted to the study of slope instability problems. Rocky, under the influence of the different geometrical parameters of the discontinuities, which could be the most important factor in controlling the stability of a rock mass. By means of stereographic projection we have updated the number of families of discontinuities as well as their dip and direction of dip for each slope in the study area, then, kinematic analysis has allowed us to highlight the different modes of failure in each slope, finally, statistical analysis of the geometric parameters of the discontinuities allows us to compare the sensitivity of the different parameters of the discontinuity networks to variations in structural conditions observed during sampling work on site. These methods are applied to the slopes of the former RN°9. The main goal of this work is based on the prioritization and qualification of the risks of falling boulders according to a quantitative method known as scoring (RHRS: Rockfall Hazard Rating System) which classifies the risk on each section of the boulder. homogeneous study, this after adding up all the scores of the criteria governing the the fall hazard and the criteria that control the vulnerability of the road net work. The application of this method makes it possible to classify 60 m of linear of index higher than 400 as "very high" risk, and 210 m of linear of index higher than 350 as "high" risk, in order to reduce the risk of landslide or boulder falls and subsequently protect the users of the RN°9 commune of Aokas (KP 24+150 to KP 25+250), it is necessary to provide protection and reinforcement works, in the most exposed rocky slopes, to reduce the risk. This method is applied for the slopes of the current RN°9.