Abstract. Natural hazards are caused by different phenomena: landslides, earthquakes, floods etc. All the manifestations of forces of nature are called phenomena. We are speaking then of natural risks when these problems are threatening, with varying degrees, human activities, causing significant damage to human life, property and the environment. The need to consider natural hazards in land use planning tasks has become a major concern. During these past years, Algeria has been hit by frequent natural disasters, with the most recent ones endangering the lives of people and causing priceless damage, faced with such a situation the company of adequate measures, capable of exercising effective prevention, is essential. In addition to the seismic risk, for which prevention still needs to be improved, Algeria must also face gravity processes such as landslides. By their suddenness, they can put people in danger and destroy entire buildings involving the evacuation of entire neighbourhoods where the financial impact is significant on the state budget and local government. The main interest of this paper is the feasibility of a plan for prevention of natural disasters related to landslides based on geological maps, topography, hydrogeological and on existing buildings and vulnerability, and eventually lead to a Zoning risk that would be considered for inclusion in the Master Plan of Urban Planning and Land Use Plan and provide support for decisions taken by local authorities for the selection of sites.

The landslide problem in the city of Constantine (Algeria) is mostly due to clayey soil, which is covering the whole area. Therefore, all the structures and foundations built over such soil are quite vulnerable. The sensitivity of this soil increases during the rainfall season, which might reach an extreme magnitude and cause damage to the structures. To understand some aspects of the failure of the mentioned soil and its mechanism, a large campaign of geotechnical characterization was undertaken using samples from the area. The specific gravity, Atterberg limits, and coefficient of lateral earth pressure at rest were determined. Samples were tested in triaxial stress path cells over a range of stresses, with the test being either stress- or strain-controlled, leading to sliding phenomena under different stress levels. The clays can be classified as over-consolidated soils. The test program and the characterization study indicated that Kois directly related to the stress history of the soil and also dependent upon the state of the sample before the test (i.e., undisturbed or disturbed). The clay minerals in the Mio-Pliocene landslide zones in Constantine are mostly montmorillonite and kaolinite, which have the lowest frictional resistance. As the montmorillonite content increases, the angle of internal friction decreases. The present study focuses on the critical state analysis since all the behavior problems of these tested samples show a peak shear strength, which is characteristic of over-consolidation materials that could lead to instability in this area. Doi: 10.28991/CEJ-2023-09-02-012 Full Text: PDF

Abstract. This paper aims to characterize materials used in the embankment for the highway, namely the identification and analysis of mechanical characteristics of materials which would be used in the construction of the East/West Motorway, section Constantine-Annaba (experimental study). However, the tests were carried out in geotechnical laboratory of the University of Constantine1. Then, for validating the results obtained in experiments, a numerical modelling of the plate bearing test by a finite element method (FEM) has been carried out using "PLAXIS" software. The numerical results obtained are in good agreement with those of the experimental.