Experimental study of the overconsolidation and saturation effects on the mechanical characteristics and residual strength of Chlef river sandy soil

This paper presents a laboratory study of the influence of the saturation evaluated in terms of Skempton´s pore pressure coefficient (B) and overconsolidation ratio (OCR) on the behavior of Chlef sand. The study is based on drained and undrained triaxial compression tests which were carried out for Skempton´s pore pressure coefficient varying between 13 and 90% and OCR varying between 1 and 8. Tests were conducted on medium dense sand samples having an initial relative density Index Id = 0.5 at an effective stress of 100 kPa. The paper is composed of two parts. The first one presents the characteristics of the sand used in this study, the second provides an analysis of the experimental results and discusses the influence of Skempton´s pore pressure coefficient (B) and OCR on the mechanical characteristics of the sand. The tests show that the increase in the Skempton´s pore pressure coefficient (B) reduces the soil dilatancy and amplifies the phase of contractancy and reduces the frictional and characteristic angle of the sand. The increase of OCR improves the stiffness of sand and accelerates the appearance of dilatancy; and increases frictional and characteristic angle of the sand. Moreover, the present study focuses on the effect of saturation and overconsolidation on the residual shear strength of sand

The undrained shear strength characteristics of silty sand: an experimental study of the effect of fines

This laboratory investigation has been conducted to elucidate how the fines fraction affects the undrained residual shear strength and liquefaction potential of sand-silt mixtures (Algeria). A series of monotonic and cyclic undrained triaxial tests were carried out on undrained, reconstituted, saturated samples of sand with varying fines content ranging from 0 to 50%. These were undertaken in order to evaluate the effect of the fines fraction on the undrained residual shear strength and liquefaction potential of loose, medium dense, and dense sand-silt mixtures (Dr = 17%, 53%, 62% and 91%), under an initial confining pressure of 100 kPa. The results of the monotonic tests indicate that the stress-strain response and shear strength behaviour is controlled by the percentage of the fines fraction and the samples become contractive for the studied relative density (Dr = 17% and 91%). The undrained residual shear strength decreases as the gross void ratio decreases, and the fines content increases up to 30%. Above this level of fines, it decreases with increasing gross void ratio. Moreover, the undrained residual strength decreases linearly as the fines content and the intergranular void ratio increase. Cyclic test results show that for the studied amplitude, the increase in fines content leads to an acceleration of liquefaction. The liquefaction resistance decreases with the increase in gross void ratio and the loading amplitude.</p

UDeploy (une infrastructure de déploiement pour les applications à base de composants logiciels distribués)

Dans le cycle de vie logiciel nous avons principalement les activités (1) de pré-développement (l analyse des besoins, les spécifications, la conception architecturale et la conception détaillée), (2) de développement (l implémentation, le prototypage, les tests unitaires et les tests d intégration) et (3) de post-développement (déploiement). Le déploiement de logiciel couvre l ensemble des activités post-développement. Les activités de déploiement permettent de rendre une application utilisable. Elles sont identifiées comme cycle de vie de déploiement couvrant l'archivage des logiciels, leur chargement, leur installation sur les sites clients, leur configuration, leur activation ainsi que leur mise à jour. Le développement de systèmes à composants a permis de mieux identifier cette partie du cycle de vie global du logiciel, comme le montrent de nombreux travaux industriels et académiques. Cependant ces travaux sont en général développés de manière ad hoc, spécifiques à une plate-forme donnée. Peu flexibles, ils s'adaptent difficilement aux stratégies des entreprises. Les systèmes de déploiement comme le montrent ceux supportés par les environnements de type intergiciel CCM, .Net, EJB développent de manière spécifique les mécanismes et outils de déploiement et introduisent des choix prédéfinis et figés de stratégies de déploiement. Nos travaux se situent dans le contexte de logiciels à base de composants distribués et portent sur la proposition d'un environnement générique pour supporter leur déploiement. C'est une nouvelle génération de systèmes proposée essentiellement par le monde académique de génie logiciel qui s'est approprié la problématique de déploiement à large échelle. Dans ce contexte, nous proposons une approche basée sur l ingénierie dirigée par les modèles où nous introduisons les abstractions nécessaires pour décrire les logiciels à déployer, les infrastructures de déploiement, les stratégies de déploiement ainsi que le processus de déploiement avec l identification et l ordonnancement des activités à accomplir et le support pour leur exécution.In the software life cycle we have mainly (1) the pre-development (requirements, specification and design), (2) the development (implementation, prototyping, testing) and (3) the post-development (deployment) activities. Software deployment encompasses all post-development activities that make an application operational. These activities, identified as deployment life cycle, include: i) software packaging, ii) loading and installation of software on client sites, iii) instance creation, iv) configuration and v) updating. The development of system-based components made it possible to better highlight this part of the global software lifecycle, as illustrated by numerous industrial and academic studies. However these are generally developed ad hoc, and consequently platform-dependent. Deployment systems, such as supported by middleware environments (CCM, .Net and EJB), specifically develop mechanisms and tools related to pre-specified deployment strategies. Our work, related to the topic of distributed component-based software applications, aims at specifying a generic deployment framework independent of the target environments. Driven by the meta-model approach, we first describe the abstractions used to characterize the deployed software. We then specify the deployment infrastructure and processes, highlighting the activities to be carried out and the support for their execution.KeywordsSAVOIE-SCD - Bib.électronique (730659901) / SudocGRENOBLE1/INP-Bib.électronique (384210012) / SudocGRENOBLE2/3-Bib.électronique (384219901) / SudocSudocFranceF

Providing Highly automated and generic means for

We present a new approach for the management and enactment of deployment process by a deployment processor ORYA (Open enviRonment to deploY Applications). ORYA aims to integrate technology relevant to process support in deployment systems. The supposed context is a large scale networked organization. The deployment processor called ORYA provides deployment functionalities to distributed, autonomous, reactive processing entities representing workstations and servers. Based on these functionalities deployment processes can be enacted and monitored in an efficient manner. In this paper we focus on the distributed, multi-server, multi-client sites architecture of ORYA and the evaluation of its application to a real industrial case study dealing with a large transportation information system