Slope Stability Study of the North Scarps at Gebel El Mokattam Area, Cairo, Egypt.

Abstract

The present work deals with the stability analysis of rock slopes and study of the physical and geotechnical characteristics of the foundation soils and rocks for the northern part of the upper plateau of Gebel El-Mokattam. This area is located to the east of Cairo, at the northern part of the upper plateau of Gebel El-Mokattam. It is bounded by El Nasr roads from west, Harrfeen Plateau from north. It is bounded from the south by El-Mokattam road and on the east by gentle slope area leading to the New Cairo City. The study area belongs to Duwaiqa and Manshiet Nasser areas, Cairo Governorate. These areas are highly populated areas with randomly built houses The geomorphic study of the area shows that the area is dissected by several wadies. The downstream direction of these wadies are toward N and NE directions which are compatible with ground gradient. These wadies are controlled by the minor faults and joints in the area. The study area contains small elevations of table lands with little scarps and separated from each other by low elevated lands. These scraps are capped by Ain Musa Bed which is highly jointed bed. These joints are recorded having vertical planes where they have dip in a range between 88°and 90°. Many rocks have been falling along these joints which led to destruction and great damages. The stratigraphic units exposed in the Study area are all of sedimentary origin. The area is belong to the Middle - Upper Eocene age. The Middle Eocene rocks are composed mainly of white limestones and marls. The Upper Eocene rocks are made up mainly of yellowish sandy dolomitic limestones, marls and claystones. The beds in outcrops are slightly dipping due to NE by 3°. This dip changes locally around the fault plane. The area is affected by a major fault lying in the northern part of the study area. The fault is oriented in the direction of N55°W, dips toward N35°E and reaches 800 m long. it is dip-slip normal fault and has a relatively small throw which is not obvious due to the extensive cover of buildings in the area. These Eocene rocks are characterized by dense fractures and joints. Joints which measured in the Upper Eocene