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Purpose The purpose of this paper is the analysis of the dissipation of pore water pressures in the core of an earth dam, under the effect of water level fluctuations in the reservoir under operating conditions, taking into account the partial emptying and filling. Design/methodology/approach The Taksebt Dam, Tizi-Ouzou, Algeria was chosen as a case study, using a two-dimensional transient finite element numerical model. The GeoStudio calculation software is used through the SEEP/W. The latter takes into account the flow in the saturated and unsaturated zone, the formulation of SEEP/W allows the analysis of the dissipation of pore water pressures in the dyke. Starting from the maximum level of the reservoir, at least one cycle of partial emptying-filling was modelled over an eight-year operating period from 2011 to 2019. The input variables were the water level variation curve, material properties and boundary conditions. Findings It can be concluded that the numerical results obtained from the simulation model on the different points studied, namely, the pore water pressures are satisfactory as long as they are close to those recorded in the field by the pore pressure cells with an average error not exceeding 10% except for some measurements where the error is 20%. When the water level in the reservoir varies, the pore water pressures vary and their behaviour follows these fluctuations. Some points in the dam are affected by negative pore water pressures. No abnormal situations have been detected pore water pressures. Originality/value The numerical results of the simulation are analysed and validated against actual pore pressure cell measurements under operating conditions.

In coastal regions, earthquakes caused severe damage to marine structures. Many researchers have conducted numerical investigations in order to understand the dynamic behavior of these structures. The most frequently used model in numerical calculations of soil is the linear-elastic perfectly plastic model with a Mohr-Coulomb failure criterion (MC model). It is recommended to use this model to represent a first-order approximation of soil behavior. Therefore, it is necessary to accommodate soil constitutive models for the specific geotechnical problems. In this paper, three soil constitutive models with different accuracy were applied by using the two-dimensional finite element software PLAXIS to study the behavior of pile-supported wharf embedded in rock dike, under the 1989 Loma Prieta earthquake. These models are: a linear-elastic perfectly plastic model (MC model), an elastoplastic model with isotropic hardening (HS model), and the Hardening Soil model with an extension to the small-strain stiffness (HSS model). A typical pile-supported wharf structure with batter piles from the western United States ports was selected to perform the study. The wharf included cut-slope (sliver) rock dike configuration, which is constituted by a thin layer of rockfill overlaid by a slope of loose sand. The foundation soil and the backfill soil behind the wharf were all dense sand. The soil parameters used in the study were calibrated in numerical soil element tests (Oedometer and Triaxial tests). The wharf displacement and pore pressure results obtained using models with different accuracy were compared to the numerical results of Heidary-Torkamani et al.[28] It was found that the Hardening Soil model with small-strain stiffness (HSS model) gives clearly better results than the MC and HS models. Afterwards, the pile displacements in sloping rockfill were analyzed. The displacement time histories of the rock dike at the top and at the toe were also exposed. It can be noted that during the earthquake there was a significant lateral ground displacement at the upper part of the embankment due to the liquefaction of loose sand. This movement caused displacement at the dike top greater than its displacement at the toe. Consequently, the behavior of the wharf was affected and the pile displacements were important, specially the piles closest to the dike top.

Earthquakes are part of the natural cataclysms that are responsible for the destruction of entire cities, causing the deaths of millions of people and often have disastrous economic consequences. Therefore, it is important to consider measures of the intensity of seismic movement in risk analysis (Potential Earthquake Harmfulness ‘PEH’). The purpose of this study is to model the mass of soil under a rockfill embankment in order to evaluate the soil settlement under the effect of an earthquake of Boumerdes (Algeria 2003) using “plaxis” finite element code. The PEH characterizes in our study the Aria intensity IA(t) and the cumulative absolute velocity CAV(t), on the one hand, and on the other hand, empirical correlations between the indicators of harmfulness (PEH) and the settlements under the base of the dike. The correlations thus obtained (Uy-PEH) are slightly influenced by the gravitational loads and a tighter dispersion of the point cloud is observed on the correlations (Uy-IA).

Slope stability analysis of earth dam is very important to ascertain the stability of the structure. The stability of earth dam depends on its geometry, components materials, water pressure and the forces to which it is subjected. Souk Tleta earth dam, currently under construction, is located on Bougdoura River, in north Algeria. The main purpose of the dam is to store surface water, for irrigation and domestic supply. In this study, reducing gradually the shear strength parameters technique is used to analyze the static slope stability of Souk Tleta zoned embankment dam based on the numerical simulation using Plaxis 2D finite element software. The deformations within the dam and the foundation at the end of construction and reservoir impoundment loading conditions and the corresponding factor of safety have been simulated. The results show that the displacements occurred in the dam body and foundation are the largest at the end of construction and lower during the reservoir filling. The safety factor in the different conditions decreases with the increase in reservoir water level.

Slope stability analysis of earth dam is very important to ascertain the stability of the structure. The stability of earth dam depends on its geometry, its components, materials, water pressure and the forces to which it is subjected.

Resume : Les parcs d'ouvrages portuaires comportent des structures complexes et variees. La connaissance de l'etat de ces structures est une condition necessaire a une bonne gestion. La demarche visant a combler le retard d'une maintenance preventive conduit a diagnostiquer une action prioritaire contre le processus de corrosion des aciers des structures metalliques et armatures des betons. Les procedes ou techniques de prevention ou de protection de type electrochimiques sont detailles par le biais de donnees emanant de cahiers des charges de chantiers a realiser ou de recents chantiers realises en construction nouvelle ou en rehabilitation. Les methodes sont comparees et les procedes de rehabilitation associes sont evoques. Notre article se concentre sur la reparation de pieux corrodes en milieu marin. Mots-cles : Ouvrages portuaires – Corrosion – Protection – Milieux marins – Methodes de protection