Volume 17 (2022): Edizione 2 (June 2022)

The present work uses a number of empirical models from geotechnical earthquake engineering (CPT-based liquefaction models) in combination with some geostatistics tools to assess the soil liquefaction potential over an extended area at the Airport of Algiers (Algeria), by the kriging approach. The SIG software program along with variograms and the kriging method were all applied together for the purpose of modeling the variation of the liquefaction potential (PL) against liquefaction in the region under study. This approach allowed determining the missing data in that region. This geostatistical method helped to draw maps at different soil depths. The results obtained revealed that the models developed were potentially capable of accurately estimating the needed data. This study made it possible to determine a number of parametric quantities that support the empirical correlation between the liquefaction potential index and liquefaction. The results show that the higher the standard deviation, the greater the uncertainty.

The region of Ain-Témouchent is a seismic zone; its land is predominately agricultural and shows complex structures, with many problems linked to the development of urbanized areas; these problems are directly or indirectly related to the geotechnical conditions of soil.

The purpose of the present research is to build a database from the different measurements carried out in the region, and to conduct tests in places where information is not available in order to consider the entire perimeter of the study area.

Once the database is completed, an analysis of all the data will be carried out using a numerical tool in order to establish the geotechnical map of the city. This map will certainly allow all decision-makers and designers to have clear and precise information when proposing or designing new structures.

The geotechnical mapping of Ain-Temouchent soils based on 178 observations divided these soils into ten groups. Eight of them according to the Unified Soil Classification System (USCS): CH (High plasticity clay), CL (Low plasticity clay), MH (High plasticity silt), ML (Low plasticity silt), SC (clayey sand), SM (Silty sand), GM (Silty gravel with sand), OH (organic soil of high plasticity). The other two groups are rocky soils: basalts (hard volcanic rock with high resistance), and limestone turf (sedimentary rock).

The cumulated effects of climate changes and accelerated urban development, amplified by insufficient funding and/or capacity to implement proactive methods and strategies for monitoring and optimization of water supply systems negatively impact the operation and overall efficiency of these systems, generating considerable problems regarding public comfort and safety and also service costs. Out of all problems, the most tangible issues for the final user are the ones related to the distribution network – the closest system component. In order to address these problems, an integrated analysis of the conditions of each urban area is required, accounting for actual water demand, pressure requirements, network configuration, power consumption and development forecasts. This article presents the set of measures proposed for optimisation of the distribution network of Babadag Town from Romania, consisting of changes intended to improve the hydraulic capacity of the network and also on reducing the water loss based on water balance evaluation and hydraulic modelling of existing and proposed network configurations.

Soil is considered an essential component of the factors that are affecting the structures. Due to the problems that are faced under various conditions while the structure is in use, the behavior of the soil is complex. The presence of cavities inside various types of soil, such as gypsum soil and the soil of some old towns, is one of its difficult problems. The formation of these cavities is due to natural and industrial causes, one of the natural causes being the dissolve of salts inside them. As for the industrial one, it is due to the presence of some old buildings. The presence of this type of cavities affects the life of the structures and as a result, it creates cracks in the foundation, therefore reducing the life of the structures.

The unexpected formation of cavities inside the soil was based mainly on some practical experiments for this research. Two cavities have been created inside the soil with different locations from the anchor to study the capacity of the anchor. The results showed that the presence of the cavity affects the capacity of the anchor according to its location from the plate as well as from the rod. The closer the cavity are to the plate; the capacity have been decreased by a certain percentage depending on the distance from the plate anchor.

The sliding of dam base along dam-foundation rock interface during earthquake excitation can decrease the earthquake response of the dam. The present study reveals a numerical simulation of the seismic failure response for Oued Fodda concrete gravity dam, located in northwest of Algeria, considering base sliding. Nonlinear finite element analyses are performed for Oued Fodda damfoundation rock system. The Smeared crack approach is used to present cracking of dam concrete under the 1980 El Asnam earthquake (M7) using Willam and Warnke failure criterion. The hydrodynamic pressure of the reservoir water is modeled as added mass using the Westergaard approach. The sliding behavior of contractions joints is modeled by surface-surface contact elements that provide the friction contact at dam-foundation interface. Drucker-Prager model is considered for dam concrete in nonlinear analysis. According to numerical analyses, several cracks may appear due to tension particularly at middle upper parts located along the symmetry central axis of the dam in both upstream and downstream faces. Although the dam sliding on its foundation reduces the magnitude of principal tensile stresses in dam body; however, the reduction magnitude is generally not large enough to preclude the cracks propagation in dam body.