Frequently, deep foundations extend through potentially liquefiable soils. When liquefaction occurs in cohesionless soils surrounding a deep foundation, the skin-friction in the liquefied layer is compromised. After cyclical forces suspend and pore pressures dissipate, effective stress rebuilds and the liquefied soil consolidates. When the settlement of the soil exceeds the downward movement of the foundation, downdrag develops. To investigate the loss and redevelopment of skin-friction, strain was measured on an instrumented micropile during a blast-induced liquefaction test in Mirabello, Italy. The soil profile where the micropile was installed consisted of clay to a depth of 6m underlain by a medium to dense sand. The 25cm diameter steel reinforced concrete micropile was bored to a depth of 17m. Pore pressure transducers were placed around the pile at various depths to observe excess pore pressure generation and dissipation. Soil strain was monitored with profilometers in a linear arrangement from the center of the 10m diameter ring of buried explosives out to a 12m radius. Immediately following the blast, liquefaction developed between 6m and 12m below ground. The liquefied layer settled 14cm (~2.4% volumetric strain) while the pile toe settled 1.24cm under elastic displacement. The static neutral plane in the pile occurred at a depth of 12m. From 6m to 12m below ground, the incremental skin-friction was 50% compared to pre-liquefaction measurements. The decrease in residual skin-friction is consistent with measurements observed by Dr. Kyle Rollins from previous full-scale tests in Vancouver, BC, Canada, Christchurch, New Zealand, and Turrel, Arkansas.

<p> The base and shaft resistance of steel pipe piles installed in silica sand is affected by several factors; these include but are not limited to: shaft resistance degradation, shaft surface roughness, installation method, pile geometry, soil density and particle size, and setup.  This thesis focuses on the first four factors, while also considering the effect of soil density within each factor. Several of the pile design formulas available do not consider the effects of shaft resistance degradation due to load cycles during installation of jacked and driven closed-ended pipe piles, plug formation and evolution during driving of open-ended pipe piles, the degree of corrosion or pitting corrosion on the shaft surface of a pile and its potential impact on setup, and the geometry of the tip of the pile. To assess the impact on pile capacity of some of these factors, a series of static compression load tests were performed in a controlled environment in a calibration chamber with a scaled down instrumented model pile. The air-pluviation technique with different combination of sieves assembled in a large-scale pluviator was used to prepare F-55 sand samples of different density in the calibration chamber. Slight changes were made to the experimental setup to study each factor: sand sample density, driving energy, mode of installation, and geometry and shaft roughness of the model pile.</p> <p><br></p> <p>The results from the experiments confirmed that each of these factors affects the pile resistance. Some of the important conclusions were:</p> <p><br></p> <p>i. The shaft resistance of the model pile is about 2.4 times greater for jacked piles than for driven piles in dense sand, due to the greater shaft resistance degradation in driven piles. </p> <p>ii. Despite the effect of degradation, the shaft resistance of the non-displacement model pile which had no loading cycles was a ratio of 0.37 to that of the driven model pile in medium dense sand and 0.60 in dense sand, due to the absence of displacement.</p> <p>iii. An increase in the surface roughness of the jacked model piles from smooth to medium-rough resulted in an increase of the shaft resistance, which had a ratio of 7.75 to the smooth pile in dense sand and 3.05 in medium dense sand. An increase from smooth to rough resulted in an increase of the shaft resistance, which had a ratio of 8.00 to the smooth pile in dense sand and 4.26 in medium dense sand.</p> <p>iv. Although rougher interfaces produce greater interface friction angles than smooth interfaces with sand, once a limiting value of surface roughness is reached, shearing occurs in a narrow band in the sand in the immediate vicinity of the model pile, with the shaft resistance depending on the critical-state friction angle of the sand. This means the shaft resistance will not increase further with changes in pile surface roughness, due to the fact that the internal critical-state friction angle of the sand has been reached in the shear band during loading.  </p> <p>v. During installation, the conical-based pile had a higher penetration per blow compared to the flat based pile from 0 to 25.6<em>B</em> in medium dense sand and 0 to 20<em>B</em> in dense sand (<em>B</em> = base diameter). After the pile was installed beyond 25.6<em>B</em> in medium dense and 20<em>B</em> in dense sand, the penetration per blow was identical. </p> <p>vi. The base resistance of a conical-based model pile was about 0.76 times that of a flat-based model pile in dense sand and 0.56 in medium dense sand. </p> <p>vii. Jacked piles had similar base resistance ratio of about 0.93 to 0.95 of driven piles in dense sand and 0.98 to 1.05 in medium dense sand. However, they had a much higher shaft resistance ratio of about 1.67 to 2.07 in dense sand and 1.44 to 1.50 in medium dense sand. </p>

Considera-se neste trabalho o projeto de estruturas de concreto para edifícios de múltiplos andares, com fundação profunda, levando-se em conta a interação solo-estrutura. Essa interação é analisada por meio de um método numérico em que a superestrutura (lajes, vigas e pilares) e os elementos estruturais de fundação (blocos e estacas) são considerados uma estrutura única, modelada pelo método dos elementos finitos e implementada no código computacional PEISE (Pórtico Espacial com Interação Solo-Estrutura), desenvolvido nesta pesquisa. O maciço de solos é representado por um modelo geotécnico proposto por Aoki e Lopes, em 1975, que utiliza a solução de Mindlin para o cálculo de deslocamentos em meio semi-infinito, elástico, contínuo e isótropo, e que considera a existência de uma superfície indeslocável, abaixo da qual as deformações do maciço podem ser desprezadas. A resposta elástica da interação solo-estrutura é subordinada a valores limites, observados em ensaios de capacidade de carga das estacas. Como forma de validar o programa e mostrar sua aplicação em problemas práticos de engenharia, resultados de exemplos foram comparados com os obtidos por outras metodologias presentes na literatura. Também, acompanhou-se o desempenho estrutural de um edifício de 26 pavimentos, com fundação em estaca hélice contínua, em sua fase construtiva, com o monitoramento de recalques e a medida de deformações em pilares, para obtenção indireta de suas solicitações normais. Os recalques foram obtidos por meio de nivelamento ótico de precisão, e as solicitações normais nos pilares foram avaliadas indiretamente, pela variação de seu comprimento, utilizando-se extensômetro mecânico removível e considerando-se as variações dos fatores ambientais e a reologia do concreto. / Design of concrete structures for multi-story buildings with deep foundation is considered in this work, taking in account the soil-structure interaction. This interaction is analysed with a numerical method where the superstructure (slabs, beams, and columns), and the foundation structural elements (blocks and piles) are considered a unique structure, modeled by the finite element method and implemented in the PEISE (soil-structure interaction in spatial frame), software that was developed in this search. The geo-technical model proposed by Aoki and Lopes (1975) represents the soil, where Mindlin\'s solution is used to calculate displacements in a semi-infinite, elastic, continuous, and isotropic environment. This solution also considers the existence of an unmovable surface, under which the soil deformations shall be neglected. The elastic response of soil-structure interaction is subordinated to limit values observed in \"in situ\" loading capacity piles tests. The examples elaboration proves the developed formulation validity through results comparison with others methodologies. Also the structural performance of a 26 story building with augercast piles was observed during the construction by measurement of settlements and columns length variation. Settlements were measured by means of optical level. Loads over columns were indirectly evaluated through column length variation, using a demountable mechanical extensometer and considering corrections due to the variation of environmental conditions and to the concrete\'s rheology.

Considera-se neste trabalho o projeto de estruturas de concreto para edifícios de múltiplos andares, com fundação profunda, levando-se em conta a interação solo-estrutura. Essa interação é analisada por meio de um método numérico em que a superestrutura (lajes, vigas e pilares) e os elementos estruturais de fundação (blocos e estacas) são considerados uma estrutura única, modelada pelo método dos elementos finitos e implementada no código computacional PEISE (Pórtico Espacial com Interação Solo-Estrutura), desenvolvido nesta pesquisa. O maciço de solos é representado por um modelo geotécnico proposto por Aoki e Lopes, em 1975, que utiliza a solução de Mindlin para o cálculo de deslocamentos em meio semi-infinito, elástico, contínuo e isótropo, e que considera a existência de uma superfície indeslocável, abaixo da qual as deformações do maciço podem ser desprezadas. A resposta elástica da interação solo-estrutura é subordinada a valores limites, observados em ensaios de capacidade de carga das estacas. Como forma de validar o programa e mostrar sua aplicação em problemas práticos de engenharia, resultados de exemplos foram comparados com os obtidos por outras metodologias presentes na literatura. Também, acompanhou-se o desempenho estrutural de um edifício de 26 pavimentos, com fundação em estaca hélice contínua, em sua fase construtiva, com o monitoramento de recalques e a medida de deformações em pilares, para obtenção indireta de suas solicitações normais. Os recalques foram obtidos por meio de nivelamento ótico de precisão, e as solicitações normais nos pilares foram avaliadas indiretamente, pela variação de seu comprimento, utilizando-se extensômetro mecânico removível e considerando-se as variações dos fatores ambientais e a reologia do concreto. / Design of concrete structures for multi-story buildings with deep foundation is considered in this work, taking in account the soil-structure interaction. This interaction is analysed with a numerical method where the superstructure (slabs, beams, and columns), and the foundation structural elements (blocks and piles) are considered a unique structure, modeled by the finite element method and implemented in the PEISE (soil-structure interaction in spatial frame), software that was developed in this search. The geo-technical model proposed by Aoki and Lopes (1975) represents the soil, where Mindlin\'s solution is used to calculate displacements in a semi-infinite, elastic, continuous, and isotropic environment. This solution also considers the existence of an unmovable surface, under which the soil deformations shall be neglected. The elastic response of soil-structure interaction is subordinated to limit values observed in \"in situ\" loading capacity piles tests. The examples elaboration proves the developed formulation validity through results comparison with others methodologies. Also the structural performance of a 26 story building with augercast piles was observed during the construction by measurement of settlements and columns length variation. Settlements were measured by means of optical level. Loads over columns were indirectly evaluated through column length variation, using a demountable mechanical extensometer and considering corrections due to the variation of environmental conditions and to the concrete\'s rheology.

L'objectif de ce travail est d'analyser l'influence du renforcement du sol par la method Soil Mixing sur le comportement des fondations superficielles et profondes. Une étude numérique a été effectuée – avec des analyses éléments finis dans ABAQUS - dans le but d'acquérir une compréhension du fonctionnement et une estimation de la performance des fondations améliorées. Pour être en mesure d'utiliser des colonnes SM pour l'amélioration de la fondation, il est nécessaire de bien comprendre leur performance sous charge axiale statique. Par conséquent, une série de simulations reproduisant des essais de chargement d'une seule colonne, et d’un groupe de colonnes ont été réalisées. Les essais à pleine et petite échelle ont été modélisés et leurs résultats comparés avec les observations expérimentales. Un bon accord entre les prédictions numériques et les mesures confirme une bonne calibration des lois constitutives des sols, des colonnes et de l’interface sol/colonne en SM. En outre, cette étude a révélé que la colonne SM agit d'une manière similaire à un pieu en béton, son comportement est régi principalement par l'interface. Ensuite, la modélisation numérique d’une fondation superficielle à petite échelle a été menée. Deux types de renforcement ont été étudiés. Le premier consiste en une seule colonne, située au centre sous la semelle analysée. Le second cas correspond à un groupe de quatre colonnes SM. Deux densités de sol ont été analysés. L'objectif de la modélisation est d'identifier l'efficacité du renforcement en termes de capacité portante de la fondation et de la réduction de son déplacement vertical. Il a été trouvé que la densité du sable a un impact significatif sur le comportement de la semelle. La variation de densité a entraîné une différence significative entre les forces totales portées par les fondations. Mais, il a été constaté que le pourcentage de la force reprise par le sol par rapport à la force total, est indépendant de la densité. L'influence du renforcement obtenu par un groupe de colonnes SM sur une fondation profonde, a été étudiée. La modélisation numérique d'un seul pieu théorique installé dans le sol homogène, a été réalisée. L'objectif de l'étude est de détecter l'impact de divers paramètres, tels que la distance horizontale entre les colonnes de SM, la distance verticale entre les têtes de colonnes et la pointe de pieu, le diamètre et la longueur des éléments SM, sur la capacité portante de la fondation. On a montré que la distance entre les colonnes et leur diamètre ont la plus grande influence sur la force de charge, la longueur de renforcement conduit à une moindre influence. / The aim of this work is to analyse the influence of soil reinforcement executed by the Soil Mixing method on the behaviour of shallow and deep foundations. Numerical investigation has been carried out - with the use of Finite Element (FE) analyses in ABAQUS - in an attempt to identify the mechanisms guiding the performance of supported foundations. To be able to use SM columns as the foundation’s improvement, it is necessary to fully understand their performance under applied static, axial load. Therefore, a set of simulations reproducing loading tests of single and group of columns have been carried out. Full and small scale tests have been modelled and their results compared with experimental observations. Good agreement between numerical predictions and measurements, confirms proper calibration of the chosen constitutive laws of: soils, columns and interactions between them. Moreover, this study has revealed that the SM column acts in a similar way to concrete pile, hence its behaviour is governed mainly by the interface. Afterwards, numerical modelling of small scale shallow foundation has been accomplished. Two kinds of reinforcement have been investigated. The first one consists of a single column situated centrally under the analysed footing. The second kind of improvement involves group of four SM columns. Two densities of soil have been analysed. The goal of the modelling is to identify the efficiency of the reinforcement in terms of: bearing capacity of the foundation and reduction of its vertical displacement. Despite significant difference between total forces borne by the foundation tested on soil with different densities, it has been found that the percentage of the total force that was taken by the soil is density independent. The influence of reinforcement executed by group of SM columns on a deep foundation has been studied. Numerical modelling of a theoretical, single pile, installed in homogeneous soil, has been carried out. The aim of the investigation is to detect the impact of parameters such as: pattern of reinforcing elements, horizontal distance between SM columns, vertical distance between columns’ heads and tip of the pile, diameter and length of SM elements, on the bearing capacity of the foundation. It has been found that the distance between columns and their diameter has the biggest influence on the borne force. However, the length of the reinforcement has shown the least significant influence.

The thesis focuses on design of 5 - square bridge foundation in Ostrava Svinov including covering of construction pits. The bridge is founded on the groups of drilled large diameter piles. Design and assessment is realized in program GEO 5. The thesis is divided into 6 parts: introduction, geotechnical circumstances, concomitant report, static calculations, technical report and documentation.

The topic of the master’s thesis is the statically compliant and economical design of the ensuring of foundation pit for building Carla Brno. The calculation part will be solved through program GEO5. The part of this thesis is also to describe the technological process of implementing elements and the relevant project documentation.

There is ussualy used the Masopust's method to assessment the piles in Czech Republic. This method is based on statistical processing of large data set of load piles tests. Due to the using of regression coefficients this method is relatively complicated and not very transparent. Instead, foreign standards ussualy use direct the values of limit stress on the base of piles and unit friction capacity. Procedure for determining the bearing capacity of the piles is thus considerably simplified. In this thesis the Masopust's method is compared with the methods used in Germany and Austria. This comparison provides insight to the safety level that include various approaches.

No description available.

The subject of my diploma thesis is the technology of steel production hall and brick administrative building in the komplex of Kabeltechnik compalny in Mikulov. Thesis deals with design of construction site, construction and technological study of construction of steel manufacturing hall, items budget according to project documentation, financial and time planing, proposal of suitable mechanical assembly including lifting mechanisms, safety of work, environmental plan and monitoring and test planing.