Global ETD Search

61	Analýza chování kořene kotvy v jemnozrnných zeminách / Behavior analysis of a ground anchor fixed length in fine grained soils Chalmovský, Juraj January 2016 (has links) Ground anchors represent an important structural element in the area of ground engineering. Despite an extensive usage of these elements, their design is usually performed using simple empirical and semi-empirical methods. An application of these procedures brings to the design a number of simplifying assumptions. The goal of the dissertation is to refine the computational design of ground anchors, analysis and quantification of selected factors significantly affecting their load displacement behavior. Firstly, the finite element method is applied. Two novel constitutive models are used: Multilaminate Constitutive Model for Stiff Soils (Schädlich, 2012) involving post peak shear softening of overconsolidated cohesive soils and Shotcrete Model (Schädlich, 2014) involving tension softening after tensile strength is reached. First constitutive model was used in order to simulate progressive decrease of skin friction along the anchor fixed length. Second constitutive model was applied for the grout material. In the next step, experimental program including several anchor load tests was carried out. The goal of the experimental program was to confirm conclusions from numerical studies and to obtain relevant data for further back – analysis. A newly developed application, in which all the findings from numerical computations and experimental measurements are incorporated, is described afterwards. The application is based on the use of so-called load-transfer functions. The program verification was conducted through series of back analysis of investigation anchor load tests realized on four different construction sites in two different types of fine-grained soils. The verification of the application is followed by series of parametric studies in which an influence of input parameters values is analyzed. Dissertation is concluded by the summarization of the most important findings.
62	Etude des dalles sur sols renforcés au moyen d'inclusions rigides ou non Antoine, Pierre-Cornélius 21 December 2010 (has links) Soft soil reinforcement by inclusion is a growing technique caracterized by a pile grid and a granular embankment introduced between the reinforced soil and the structure. Unlike traditionnal methods, the load is partially transferred to the pile heads by arching in the embankment. The application area of this research focuses on the shallow foundations case, in which the thickness of the embankment is small. The litterature review shows that only a few studies were dedicated to that case, and that fundamental questions remains concerning the load transfer in the embankment. Chosen method for this research consists in two-dimensionnal physical modelling, analysis of the conducted simulations, and development of an analytical model in order to predict the load transfer to the piles by arching in the embankment. The results of this PhD thesis provide original elements of evidence of the load transfer in the studied system, proposes an analytical model based on block division of the granular embankment by shear bands - which is in good agreement with experimental data - and lead to a better understanding of arching in soils. pieu modélisation physique sol analogique effet voûte efficacité load transfer mechanism displacement and strain fields punching conditions d’appui analogic soil physical modelling granular embankment pile traquage de particules dans une image champ de déplacement et de déformation poinçonnement bande de cisaillement découpage en blocs support conditions shear band efficiency arching image analysis particle image tracking mécanisme de transfert de charge shallow foundations remblai granulaire fondation superficielle renforcement des sols soft soil sol compressible soil reinforcement block division soil-structure interaction / inclusion analyse d’images dalle interaction sol-structure slab inclusion
63	Etude des dalles sur sols renforcés au moyen d'inclusions rigides ou non Antoine, Pierre-Cornélius 21 December 2010 (has links) Soft soil reinforcement by inclusion is a growing technique caracterized by a pile grid and a granular embankment introduced between the reinforced soil and the structure. Unlike traditionnal methods, the load is partially transferred to the pile heads by arching in the embankment. The application area of this research focuses on the shallow foundations case, in which the thickness of the embankment is small. The litterature review shows that only a few studies were dedicated to that case, and that fundamental questions remains concerning the load transfer in the embankment. Chosen method for this research consists in two-dimensionnal physical modelling, analysis of the conducted simulations, and development of an analytical model in order to predict the load transfer to the piles by arching in the embankment. The results of this PhD thesis provide original elements of evidence of the load transfer in the studied system, proposes an analytical model based on block division of the granular embankment by shear bands - which is in good agreement with experimental data - and lead to a better understanding of arching in soils. / Doctorat en Sciences de l'ingénieur / info:eu-repo/semantics/nonPublished Bâtiments génie civil transports Sciences de l'ingénieur Building materials Tiles Earthwork Soil-structure interaction Construction -- Matériaux Carreaux Terrassement Interaction sol-structure pieu modélisation physique sol analogique effet voûte efficacité load transfer mechanism displacement and strain fields punching conditions d’appui analogic soil physical modelling granular embankment pile traquage de particules dans une image champ de déplacement et de déformation poinçonnement bande de cisaillement découpage en blocs support conditions shear band efficiency arching image analysis particle image tracking mécanisme de transfert de charge shallow foundations remblai granulaire fondation superficielle renforcement des sols soft soil sol compressible soil reinforcement block division soil-structure interaction / inclusion analyse d’images dalle interaction sol-structure slab inclusion

Page generated in 0.0545 seconds