Relationship between Horizontal Bedding and joints Affecting Rocks Slopes Parallel to Al-Rujban Mountain Road, Libya

Abstract

The bedding planes and rock joints contribute to the weakening of the rock masses forming the slopes, increasing the likelihood of rockfalls and collapses. This study aims to analyze the relationship between horizontal bedding planes and rock joints and their effect on the stability of rock slopes parallel to the Rajban mountain road. The horizontal bedding planes represent the primary sedimentary structures of the rocks. To achieve the study objectives, the physical characteristics of joint surfaces and bedding planes were examined. Field observations of the Sidi Saad Formation (Ain Tobi Member) showed that horizontal bedding planes are the main structural weakness surfaces, with variations in thickness and lateral continuity. The joint spacing was about 0.20 m, and the values of Jv = 9.8 and RQD = 85.1% indicate relatively good rock quality. The results also reveal that the convergence of bedding planes increases weak points and promotes the development of vertical joints, reducing layer cohesion and increasing the likelihood of failure on steep slopes.