Rock Fall Failure Model practical example of Umm Sid Plateau-Sharm El Sheikh area, Egypt

Abstract

Abstract: A severe rock fall in the upper jointed reefal limestone unit which represents the main foundation rock bed of Umm Sid plateau .The main causative factors of rock fall is the movement of the limestone blocks under the effect of deferential erosion (undercut ) of the underneath sandstone unit. Photogeologic mapping and Geological Field measurements have been carried out for the Umm Sid plateau to investigate the factors controlling the rock fall of the uppermost layers of the plateau. The geological field measurements as well as geological disk studies are used to produce a model representing the joint orientations, stability model and failure mechanism geologic model. Kinematic analysis of the acquired indicated that the topmost unit of the plateau is affected by three main sets of joints E-W, NE-SW and NW-SW trends. The reefal hard limestone unit is underlying with relatively soft sandstone unit. The sand stone unit is intercalated with marl and clays that increase the potentiality of deferential erosion. Kinematic analyses of the measured joints were studied by using Hoek and Bray failure methods (2004), Dips program Version 5.1.8 and RocPlane Version 2.0. The site observation and measurements indicated that the rock falls is seriously active and accordingly the scarp edge retreat and that may lead to a dangerous impact on the existing hotels and resorts by the plateau. Key Words: Sharm El Sheikh (Umm Sid Plateau), Kinematic analyses, Rock fall and Failure model.