Slope instability, landsliding and hazards analysis at highway roadcut تحليل عدم استقرار المنحدر والانهيارات الأرضية والمخاطر في شق الطريق

Abstract

The stability of rock slopes is crucial to public safety in highways passing through rock cuts. Slope instability and failures occur due to many factors such as adverse slop geometries, geological discontinuities, weak or weathered slope materials as well as severe weather conditions. External loads like heavy precipitation and earthquakes could play a significant role in slope failure. The main objective of this study is to assessment the stability of rock slopes throughout the passing highway and hazard potentiality. In this paper, several rock mass classification systems for rock slope stability assessment were critically evaluated against known rock slope conditions in the northeastern region of Libya to includes two areas are Al Bakour area and Al Shaliony area that located east Benghazi city. The investigated rock formations in both areas are mainly formed of carbonate rocks that represented by chalk, limestone, dolomite in addition to the intercalated shale, with cliffs features of slope angle ranging from 70 to 90º. Also, these formation are highly topographic features and varies in thickness and extensions as well as structurally patterns. The stability conditions were identified and the stability of the rock cuts have been evaluated using different procedures e. g. determining the most relevant factors affecting slope instability; interpreting the discontinuity data collected from the surveys for the assessment of the modes of failure and determining the potential unstable zones. This study reveals that the cut needs to be mitigated because of the a few outcrops of rock slopes that covered by the metal mish not enough to support protection against rock collapse an failure ongoing slope instability present in some areas, that including planar and wedge slides and raveling rock falls. It was found that the unstable rock areas create serious safety hazards to traffic.

Arabic abstract available in PDF