Bearing Capacity of Embedded Strip Footings on Cohesionless Soil Under Vertical and Horizontal Loads

In the last decades a few attention was given to the evaluation of the bearing capacity of embedded footing under inclined loads on a frictional soil. This paper focuses on a numerical study using the finite-difference code Fast Lagrangian Analysis of Continua (FLAC), to evaluate the bearing capacity of embedded strip footing on a frictional soil. The soil is modeled by an elasto-plastic model with a Mohr–Coulomb yield criterion and associative flow rule; the effect of non-associativity of the soil on the bearing capacity is also investigated. The effect of the embedment is estimated though a depth factor, defined as a ratio of the bearing capacity of a strip footing at a depth D to that of a strip footing at the ground surface. The inclination effect is estimated by inclination factors, defined as the ratio of the limit vertical load for a footing under inclined loading to that of the vertically loaded footing. Both swipe and probe analyses were carried out to identify the vertical force–horizontal force (V–H) failure envelope. The results have been compared with those available in the literature.     

The El Achour (Algiers,Algeria) landslide delimitation using the H/V ambient vibration method

We present in this work investigations using seismic ambient vibration to delimitate the El Achour landslide (Algiers), upon which independent geotechnical studies were carried out. Acquisition campaign of ambient vibration on the El Achour site on June 2009 and June 2015, over a surface of about 2 ha, consisted of 64 records of ambient noise with a 10 to 20 m grid size. This approach consists of simple, light, and fast H/V acquisitions, in order to determine the extension of the unstable zone, the depth of the sliding surface, and to test the effectiveness of this method. Two peaks were interpreted as one being for the sliding surface and the other for the lithological interface. As results, in the stable area, they are satisfactory. Indeed, the points in this area are not intermediate peaks which could be related to potential sliding surfaces, which led us to think that we could delineate, using this method, the unstable area from the stable area. The HVSR method allows to determine the thickness of the geological formations and to highlight the lateral and vertical facies changes in broad area.     

Clay and Marl Formation Susceptibility in Mila Province,Algeria

In Mila Province, Algeria (a.k.a Mila Wilaya), sensitive clays presenting shrinkage-swelling phenomena are widespread, covering large areas. Due to this, constructions and infrastructures sustainability built on such soils is questionable. Such clays sensitivity is amplified by seasonal rainfall deficits which reaches extreme magnitudes. In order to develop disasters’ prevention measures, we present in this work, areas mapping susceptible to shrinkage-swelling phenomenon by adopting a French method developed by B R G M. This method takes into account three measurable characteristics: i.e. lithological, mineralogical and geotechnical, of clayey formations identified in the studied sector. Based on these characteristics, three scores are attributed for each formation. Then, the susceptibility index is the obtained score average for each clayey formation. The susceptibility map is established on this index basis with three classes: low, medium, high.     

Detection of sinkholes using 2D electrical resistivity imaging in the Cheria Basin (north–east of Algeria)

Sinkhole collapse is one of the main limitations on the development of karst areas, especially where bedrock is covered by unconsolidated material. Studies of sinkhole formation have shown that sinkholes are likely to develop in cutter (enlarged joint) zones as a result of subterranean erosion by flowing groundwater. Electrical resistivity imaging or tomography (RESTOM) is well suited to mapping sinkholes because of the ability of the technique for detecting resistive features and discriminating subtle resistivity variations. Two-dimensional electrical resistivity tomography surveys were conducted at two sinkhole sites near Cheria city where limestone is covered by about 10 m of clayey soils. A Wenner transect was conducted between the two sinkholes. The electrode spacing was 2 m. The length of transect is about 80 m. The survey results suggest that RESTOM is an ideal geophysical tool to aid in the detection and monitoring of sinkholes and other subsurface cavities.     

Energy Performance Improvement of a Solar Still System Using Date and Olive Kernels: Experimental Study

Currently, solar distillation systems are used to contribute to solving the fresh water supply deficiency problem in some desert and rural areas. The present outdoor experimental work aims to improve the energy performance of a solar still installed in a semi-arid region. Experiments are performed using three solar distillers (a reference system, a distiller with date kernels, and one with olive kernels). The integration effect of two kernel types date and olive with different concentrations in the range of 300–600 g kernels per 5 L on the hourly and cumulus water production, and thermal and exergy efficiencies are analyzed. The results show that, for the same kernel mass concentration, the system with olive kernel is more effective than that with date kernels; moreover, compared to the reference system, cumulus water production of these systems at a mass concentration of 500 g kernels per 5 L is higher by ≈226% and 176%, respectively. At a concentration of 500 g kernels per 5 L, the average daily thermal efficiency of the solar still with olive kernels and that with date kernels is 38.01% and 30.7%, respectively, and their daily average exergy efficiency is 8.4% and 3.1%, respectively.     

Mediterranean Sea and anthropogenic influences on ambient vibration amplitudes in the low-frequency and high-frequency domains in the Algiers region

Ambient vibrations have been continuously recorded at Dar El Beida, about 20 km from Algiers (Algeria). This data set allows determining that, in the low-frequency domain (<1 Hz), ambient vibration sources are mainly linked to Mediterranean Sea effects, while in the high-frequency domain, they are closely related to anthropogenic activity. Climatic conditions have an influence on the ambient vibration spectral amplitudes in the low-frequency domain, which is not the case in the high-frequency domain. The limit between the low-frequency and high-frequency domain, based on natural versus anthropogenic activity, is not clear cut and lies between 1.25 and 1.50 Hz. Variations of H/V peak amplitudes in the low-frequency domain are clearly linked to the climatic conditions. In the high-frequency domain, H/V peaks are not related to climatic conditions and cannot be clearly related to anthropogenic source changes.