Probabilistic analysis of piled earth platform under concrete floor slab

International audienceThis paper proposes a two-dimensional axisymmetric numerical modelling of an earth platform over a clayey sand improved by stiff vertical piles using a finite-difference continuum approach. The study focuses on the surface settlements and the stress efficacy of the improvement system. Only the soil parameters are considered as random variables and two assumptions (normal distribution or nonnormal distribution) are used. The first-order reliability method (FORM) is applied to calculate the reliability index. Response surface methodology (RSM) allows for access to the Hasofer-Lind reliability index and is optimized by the use of a genetic algorithm. The Hasofer-Lind reliability index is calculated for two distinct cases. Firstly, only the geomechanical parameters of the clayey sand are considered as random variables; secondly, the parameters of both the clayey sand and the earth platform are considered. The results show that the reliability of a single soil layer is safer than the reliability of the whole syste

Estimation of dynamic impedance of the soil-pile-slab and soil-pile-mattress-slab systems

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Reliability analysis of a mechanically stabilized earth wall using the surface response methodology optimized by a genetic algorithm

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Seismic response of a rigid foundation embedded in a viscoelastic soil by taking into account the soil-foundation interaction

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Probabilistic analysis of ultimate seismic bearing capacity of strip foundations

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Dynamic Response of Pile Reinforced Soils and Piled Foundations

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Biotechnology Agroalimentary and Biomedical Analysis Group, Department of Biology, Faculty of sciences, Moulay Ismaïl University, B. P. 11201, Zitoune, Meknes, Morocco

An electronic microtongue using an electrochemical microcell was designed to monitor wastewater quality. The planar electrochemical microcells were micromachined in a microcrystalline Boron Doped Diamond (BDD) thin layer using a femtosecond laser. The electrochemical measurements with these BDD microcells were conducted using Differential Pulse Anodic Stripping Voltammetry (DPASV) for the major detection of heavy metal ions. Global signal obtained for raw wastewater (influent of Waste water Treatment Plant (WWTP)) and for water from Arve river were found much higher than those of treated wastewater (effluent of WWTP) and of treated wastewater from hospital. The DPASV signals have been processed by Principal Component Analysis (PCA) and K- Nearest Neighbours (K-NN). According to PCA results, waters were identified and discriminated with 99.75 % of the total variance of the dataset. Using K-NN with cross-validation approach, a good performance of the developed model was achieved for K=1 and 100 % of the samples were able to be classifiedin their original groups

Non Destructive Evaluation of containment nuclear plants structure

International audienceFrench Projects of Investment for the Future, called “Research for Nuclear Safety and RadiationProtection” have been initiated to further research on the causes, the management, the impact of theobserved nuclear accidents and to propose and validate solutions to limit the risk and the consequences.In this context the "Non Destructive Evaluation of nuclear plants containment” project” (ENDE) witheight partners (six research institutes and two industrials) supported by the “National Agency of Research”,proposes a methodology for the Non Destructive Evaluation of the containment capacity to fulfil its twomajor functions: strength and leak tightness. The NDE measurements will be performed underconditions representing the specific solicitations of a decennial inspection, and after or during areference accident.The project aims to develop NDEs, to combine them by data fusion and to select the most efficientcombinations with quantitative criteria.The work is based on:• Structuring the knowledge and developing an experimental plan.• Evaluating the material in representative conditions of accidental solicitations (water saturation,porosity, strength, elastic modulus, stress) and the diffuse thermal damage (micro cracks)• Monitoring the transition from diffuse to continuous damage (cracks) and monitoring a crack understress (opening and width).• Implementing ND Techniques on-site.The ND techniques retained after selection will be implemented on a containment mock-up on the 1/3scale. This mock-up developed by EDF (Electricité de France) will be available in 2016. It will becomparable to those of real size containment regarding pressure and temperature conditions. Themeasures deduced from the NDEs will be introduced in another project (Macena) that aims to simulatethe water and heat transfers as well as creep occurring in a reference accident. We will present themethodology and the results obtained during the first year and a half