Slope Stability Hazard Assessment and Mitigation Methodology Along Eastern Desert Aswan-CairoHighway, Egypt

Abstract

The highway between Aswan and Cairo on the eastern bank of the Nile Valley is one of the most used highways in Egypt, connecting most of the governorates with each other. It represents the backbone of Egyptian transportation and commercial traffic. This Highway passes through a two kilometer section of rock cut located 20 km north of New Assiut city. Serious stability and rock fall issues have been recognized in this section in the past few years. In this study the stability of the rock cuts have been evaluated using different techniques including: 1) Determining the most relevant factors affecting slope instability; 2) interpreting the discontinuity data collected from the joint surveys using stereographic projection for the assessment of the modes of failure and determining the potential unstable zones; 3) applying a rock fall simulation program(s) to evaluate the potential rollout distance for the falling rocks; 4) applying the Missouri Rock Fall Hazard Rating System (MORFH RS). Finally, the most optimum mitigation method that will decrease and minimize the consequences of slope instability was determined. This study reveals that the cut needs to be mitigated because of the ongoing slope instability present in some areas, including planar and wedge slides and raveling rock falls. It was found that the unstable rock areas create serious safety hazards to traffic.