Study of the Causative Factors of El-Ghandouri Landslides and their Stabilization Methods

Abstract

Tangier landslides are considered a common engineering problem throughout the construction of different roads or other engineering works in the north of Morocco. This research paper aims to identify the main causes of landslides in an area with an important tourist site to search for the most appropriate engineering solutions. Several geotechnical studies were carried out through boreholes up to 30 meters deep to determine the main causes of the landslides. These studies exhibit that the main reason for landslides is the presence of Layers of soil with weak mechanical properties, which are highly affected by rainfall. The limit equilibrium (LE) analysis method and finite element (FE) method was utilized to analyze the stabilities of the EL Ghandowri slopes before excavation, after excavation, and after stabilization treatment of the slopes for construction. The analysis results indicated that the EL Ghandowri slopes, before any excavation, were unstable in their natural state. The reinforced concrete piles' row with anchors and concrete piles cap were the stabilization methods, which give the best safety factor and horizontal deformation results. The soil-structure interaction method (SSIM) and finite element (FE) method were used to calculate the horizontal deformation of piles. The occurrence of EL Ghandouri landslides can be reduced if the main reason is addressed; thus, the problem of Tangier Province landslides, especially EL Ghandouri, should be given big attention throughout the survey and design of the engineering works, not only during the construction.