Case Study of Landslides in Kabylia Region, Algeria

Kabylia is mountainous and coastline region of Algeria. Every year, particularly in the winter, it is affected by landslides displacing an important volume of detritic materials, and causing damages to infrastructures, housing and public facilities. It takes place in geological formations that are particularly favourable to this type of movement, because of the heterogeneity of their facies and the impermeability of some layers. Experience shows that the main cause of the landslides in this region is the combination of several passive and active factors, as geology, morphology, hydrology, climate and anthropic activities. The exceptional rains of winter 2012 triggered a series of landslides in this region, among which the landslide occurred at PK 226+300 of the National Road RN 24, at a place named Assoumeth-Boulimat, Béjaia department, is one of the most spectacular. The landslide caused the collapse of a section of the road of about 120 meters, with a main scarp of about 8 meters. During the firstly time of the field observation, 18 hours, the landslide mass and the road moved 10 meters. This paper describes this landslide triggered by rainfall and unfavourable geological, hydrogeological and geotechnical conditions. The geotechnical study and methodology of stabilization in two phases will be presented and discussed. Stability calculations were conducted to understand the triggering of the landslide

Differential Settlements of Cylindrical Steel Storage Tanks: Case of the Marine Terminal of Bejaia

The marine terminal of Bejaia is a zone of storage of hydrocarbon liquids. It consists of sixteen cylindrical floating roof steel tanks founded on a reconstituted and compacted granular fill. At the end of 1980s, after about 25 years of satisfactory service, the tanks were subjected to settlements, ovalization and tilting. Because of a distortion of the steel tank walls and jamming of the floating roof, a shear failure was evident and some tanks were considered unsafe for service. A comprehensive geotechnical investigation was conducted to evaluate the subsurface conditions of the site and to provide recommendations for foundation repair or retrofit of existing tanks as well as foundation design for new tanks and related facilities. It was concluded that the soils underneath each tank to be improved. Micropiling has been chosen to strengthen the soil beneath the foundation. The proposed paper describes and discusses the case study, the method of treatment adopted in the field and the results of numerical modeling, and gives some lessons learnt

Response of RC columns with transient creep in a natural fire environment

The aim of this study is to investigate the effect of transient creep on the structural response of RC columns subjected to natural or parametric fires using a finite element model developed by the authors. The model, capable of analysing the response of RC columns from pre-fire stages to collapse in fire environment, is specially developed for the analysis of RC structures under severe thermo-mechanical loads, which accounts for transient creep explicitly as an additional component of the total strain of the concrete or implicitly through the use of the materials’ properties recommended by EC2. Through the obtained results, it is shown that the transient creep phenomenon significantly influences the fire response of RC columns. It was also found that the conventional method based on standard fire exposure may not be conservative if the resulting fire has a decay phase similar to the severe fire scenario used in this work

Construction et réutilisation de spécifications LOTOS

Colloque avec actes et comité de lecture. nationale.National audienceNotre objectif est d'assister le spécifieur dans sa démarche de construction, de réutilisation et d'adaptation de spécifications LOTOS. Nous utilisons pour cela le modèle Proplane qui permet de décrire différentes étapes de développement de spécification et de mémoriser les décisions prises ainsi que leurs justifications. Dans ce papier, nous présentons une approche de construction de spécifications LOTOS : le style orienté processus et étudions deux exemples de réutilisation : adjonction d'un composant dans une architecture et réutilisation d'un style d'architecture