Orientador: Paulo José Rocha de Albuquerque / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo / Made available in DSpace on 2018-08-25T01:37:35Z (GMT). No. of bitstreams: 1 MunevarPerez_NurianBibiana_M.pdf: 5528282 bytes, checksum: e5a5f3821f445a373ac23f94b7e64ece (MD5) Previous issue date: 2014 / Resumo: Esta Dissertação teve por objetivo analisar o comportamento de estacas escavadas à trado com três diferentes diâmetros, instrumentadas, submetidas a provas de carga estática. Para isto, foram executadas três estacas com diâmetros de 0.25 m; 0.30 m e 0.40 m, com comprimento de 5.0 m, no Campo Experimental da Faculdade de Engenharia Civil, Arquitetura e Urbanismo ¿ FEC-UNICAMP. A primeira parte da pesquisa consistiu em uma compilação da teoria da transferência de carga e dos métodos teóricos e semi-empíricos para o cálculo da capacidade de carga; em que se utilizou o banco de dados geotécnicos de resultados de ensaios de campo (SPT, CPT, SPT-T) e resultados de laboratórios realizados no local. A segunda parte consistiu no desenvolvimento experimental da pesquisa, em que foram realizadas três provas de carga estáticas do tipo lentas, instrumentadas com extênsometros elétricos no topo e na ponta de maneira a se obter os dados do mecanismo de transferência de carga em profundidade. A partir da realização das provas de carga verificou-se que os ensaios forneceram um valor de carga de ruptura de 180 kN, 210 kN e 240 kN, para as estacas de 0.25m, 0.30m e 0.40m, respectivamente. De acordo aos resultados da instrumentação, as estacas trabalharam preponderantemente por atrito lateral. Observou-se que os métodos semi-empíricos e teóricos, superestimaram a carga de ponta e subestimaram a carga de atrito lateral. Verificou-se que o método Décourt e Quaresma (1996) com a utilização do coeficiente ?=2, foi o que melhor se aproximou e adequou ao local em estudo / Abstract: The objective of this dissertation is analyze the behavior of three bored piles with different diameters, instrumented, subjected to static load tests. For this, it were executed three piles with diameters of 0.25 m; 0.30 m and 0.40 m, with 5.0 m of length at the Experimental Site of School of Civil Enginering, Architecture and Urban Design at University of Campinas ¿ Unicamp. The first part of this research consisted in a compilation of load transfer theory and the study of theoretical and semi-empirical methods for the calculation of load capacity, which used the geotechnical data results of in situ tests (SPT, CPT, SPT-T) and laboratory results performed on site. The second part consisted in the development of experimental research, where three slow static load tests were performed, instrumented in depth with strain gages on top and at the tip in order to obtain information on the load transfer mechanism in depth. After performed the load tests it was found that the tests provide a value of rupture load of 180 kN, 210 kN and 240 kN, for piles of 0.25 m, 0.30 m and 0.40 m, respectively. According to the results of the instrumentation, the pile¿s behavior were predominantly by skin friction. It was observed that the semi-empirical and theorical methods overestimated the load of tip e underestimated the load skin friction. It was found that the Décourt and Quaresma (1996) method using the coefficient ? = 2, which was approached and best suited to the site under consideration / Mestrado / Geotecnia / Mestra em Engenharia Civil

Orientador: Paulo José Rocha de Albuquerque / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo / Made available in DSpace on 2018-08-22T22:52:11Z (GMT). No. of bitstreams: 1 Schulze_Tami_M.pdf: 4860643 bytes, checksum: 3184896c9208ecb4e980c04642404cc3 (MD5) Previous issue date: 2013 / Resumo: Esta pesquisa apresenta uma análise dos resultados da aplicação dos métodos semiempíricos para o cálculo da capacidade de carga do sistema solo - estaca por meio do valor de referência obtido por uma prova de carga instrumentada em profundidade. Para tanto, estudou-se uma estaca escavada por trado mecânico, com diâmetro de 0,25m e comprimento igual a 5,0m e executada no solo do tipo laterítico na região de Campinas-SP. Os parâmetros geotécnicos utilizados foram obtidos a partir de ensaios in-situ (SPT-T, CPT, DPL, DMT), realizados no local. Através da análise da curva carga vs. recalque pelo critério de rigidez de Décourt (1998), constatou-se que o sistema solo - estaca apresentou ruptura física e capacidade de carga de 183kN. Os dados da instrumentação revelaram que a estaca em estudo caracterizou-se como uma estaca de atrito. Os resultados dos métodos semi-empíricos foram agrupados de acordo com: tipo de ensaio in-situ utilizado, tipo de ruptura considerada e distribuição da carga de ruptura total nas parcelas de ponta e lateral. Verificou-se que os resultados de aplicação dos métodos de previsão de capacidade de carga apresentaram uma dispersão elevada dos valores. Observou-se que 93% dos métodos semi-empíricos forneceram resultados abaixo da capacidade de carga obtida da prova de carga / Abstract: This research presents a comparative analysis of the results of the bearing capacity of the soil - pile system calculated by the semi-empirical methods, and the reference value obtained by the instrumented static load test. Therefore, it was studied a mechanical bored pile with 0,25m of diameter and 5,0m of length that was constructed in a lateritic soil deposit on the region of Campinas-SP. The soil parameters needed for the calculations were obtained from in-situ tests (SPT-T, CPT, DPL, DMT), executed in the same place. Based on the load vs. settlement curve analysis and on the rigidity criterion of Décourt (1998), it was found that the bearing capacity of the soil-pile system was 183kN, and it presented ultimate failure. The data collected by straingages installed in the pile showed that the studied pile was classified as a friction pile. The results of the semi-empirical methods were grouped according to the type of in-situ test, type of the failure (ultimate failure, settlement limit) and the distribution of the ultimate load in: toe resistance and shaft resistance. It was verified that the results of the methods to predict the bearing capacity showed large dispersion of the values. It was observed that 93% of the semiempirical methods used in this study presented results below the bearing capacity obtained by the static load test / Mestrado / Geotecnia / Mestra em Engenharia Civil

No description available.

O presente trabalho tem como objetivo avaliar a influência do efeito da corrosão no comportamento geotécnico de condutos enterrados através da utilização de ensaios em modelos reduzidos. Foram empregados diferentes padrões de corrosão, em que se variou o grau e a localização da corrosão. Os resultados do trabalho mostram as localizações mais danosas à estrutura, correlacionando resultados dos tubos corroídos com os de tubos intactos. O duto danificado desencadeou um carregamento assimétrico que deve ser considerado para a prevenção de possíveis deslocamentos. Finalmente, o trabalho avalia a influência conjunta da corrosão e da flexibilidade do conduto no comportamento mecânico das tubulações enterradas. De modo a permitir comparações para averiguar a validade do modelo laboratorial adotado, utilizaram-se simulações numéricas, que possibilitam o estudo do problema de forma mais abrangente. / This work evaluates the influence of corrosion effect on the geotechnical behavior of underground conduits. Small-scale tests were carried out on two different types of pipes, in which the degree and location of the corrosion were changed. The results show the most harmful corrosion locations relative to the intact conduits. The damaged conduits built in and located under asymmetric condition behave as if they were subjected to an asymmetric loading condition and this must be considered to the prevention of possible displacements. Finally, the work evaluates the joined influence of the corrosion and conduit\'s flexibility on the mechanical behavior of underground pipelines. To allow comparisons to inquire the validation of the adopted laboratorial model, numeric simulations were used, which enable the study of the problem considering other corrosion layouts.

Topic of this master`s thesis is founding of the hightway bridge, which is located between Lipník and Bělotín. Thesis is aimed for creating shallow foundation and foundation on piles and choosing which option is better. All evaluations have been made without specialized software and than compared with GEO5 results. Better solution will be completed with procedure for construction and drawing documentation.

The diploma thesis is devided into two levels. The Primary part of the thesis is the theoretical part, which is part of project „FV10588 – New generation of spatial prefab made from high-firm concrete with increased mechanical resistence and endurance“, realized in cooperation with Faculty of Civil Engineering at VUT university – Institute of concrete and masonry structures. The project deals with frame corners in the form of steel and composite reinforcement which will compared through experiments and various kind of calculate proceedings. The secondary part of thesis focuses on the static-design project of cooling reservoir, placed under the ground, while is stressed by temperature. The reinforcement of the construction is realized in two ways – steel and composite reinforcement with their effectivity compared.

京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第20327号 / 工博第4264号 / 新制||工||1661(附属図書館) / 京都大学大学院工学研究科都市社会工学専攻 / (主査)教授 三村 衛, 教授 大津 宏康, 准教授 肥後 陽介 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

<p>Shallow foundations are used to support small-to-medium size structures, and their capacity derives from the strength of strong, near-surface soils. The design of shallow foundations is done by proportioning the plan dimensions of the foundation element by considering three factors: (1) the structural stability of the foundation, (2)  the allowable bearing pressure of the soil supporting the foundation to prevent ultimate bearing capacity failure, and (3) the tolerable total and differential settlements to meet serviceability requirements under normal working loads. Different theories have been developed to estimate the bearing capacity of a foundation, mostly relying on the Terzaghi (1943) form of the bearing capacity equation with the superposition of three terms. The partly theoretical and empirical methods of bearing capacity predictions rely on an assumed failure mechanism within the soil. In addition, the soil itself is considered to be a perfectly plastic material and its strength is accounted for through non-dimensional bearing capacity factors. However, the boundary-value problem of footing penetration, in reality, is quite complex and the use of the traditional bearing capacity, with use of the principle of superposition, leads to somewhat conservative results. The challenges involved in a footing penetration problem emanate not only from the difficulties in estimating soil strength parameters but also because the footing penetration problem involves large deformations and strains, which localize to form shear bands that propagate in the soil domain until the "collapse" of the sand-footing system.</p> <p>The overarching aim of this research is the study of the response of shallow foundations on clean silica sands by investigating the measured bearing capacities and getting insights into the failure mechanisms that develop as a result of the soil displacements below the base of the foundation element. This was experimentally achieved using a combination of physical modelling (by performing a series of model footing 1g load tests inside a novel half-circular calibration chamber) and image analysis (using digital image correlation technique). The load-settlement response of the model footings is investigated by performing displacement-controlled load tests on model strip and square footings placed either on the surface or embedded in the sand samples of varying relative densities prepared inside the calibration chamber using the method of air-pluviation. A series of high-resolution images collected during model footing loading were analyzed using the digital image correlation (DIC) technique to obtain the displacement and strain fields in the sand domain. Two fully characterized silica sands, Ohio Gold Frac (OGF) and Ottawa 20-30 (OTC) are used in the research. Different testing variables that were considered in the experimental setup are: (1) sand particle morphology, (2) sand sample's relative density, (3) sand layer thickness, and (4) footing shape, size, and embedment depth. A detailed test matrix was formulated to isolate these variables and study the effects of each on both the bearing capacity and the associated failure mechanism. Accordingly, this article-based dissertation is organized to describe the results of three studies.</p> <p>In the first study, the effects of relative density and particle morphology on the bearing capacity and failure mechanism of a model strip footing were investigated. This was done by using two silica sands: OGF sand and OTC sand, both the sands have comparable mineralogy, gradation, and particle sphericity; however, they have markedly different values of particle roundness. Samples of both sands were prepared at relative densities of 90%, 65%, and 30%. The evolution of the footing's collapse mechanism was considered by selecting relevant points on the load-settlement curves. A novel methodology was adapted to record the thickness of the shear band that developed in the sand domain. In the second study, the effects of the presence of a stiff layer below the strip footing were investigated. This was achieved by load testing the model strip footing on OTC sand layer of limited thickness. To simulate the sand-bedrock system, a half-circular steel plate supported by a stack of hollow concrete blocks was used. Load tests on model strip footing were performed on OTC sand samples without the presence of a stiff base and on the sand samples underlain by a stiff base located at depths equal to 0.5B and 1B below the base of the footing. The effect of the presence of the stiff base on the limit unit bearing capacity of the footing and stiffness of the sand-footing system were investigated. In addition, the contours of the cumulative maximum shear strains, horizontal displacements, and vertical displacements that develop in the sand layer are presented for both cases of with and without the presence of the stiff base. In the third study, the effects of footing geometry and embedment on the bearing capacity and failure mechanism were investigated. Load tests were performed on surface and embedded model strip and square footings on dense, medium dense, and loose OTC sand samples. The effects of choice of flow rule (associative versus non-associative) on the bearing capacity calculation and the increase in bearing capacity due to footing embedment (bearing capacity ratio) were determined. In addition, a framework is proposed to experimentally determine the shape and depth factors using strip and square footings of equal widths considering the flow rule non-associativity, conditions of low confinement, and different loading paths.</p> <p>The results of the experimental program presented in this research on bearing capacity, displacement fields, strain fields, and failure mechanisms for different footing sizes and shapes under different testing conditions show that that the footing's collapse mechanism depends on the relative density of the sand sample, sand particle morphology, and the footing geometry. Significant differences in the bearing capacity of model footings due to sand particle morphology and sand sample density were observed. The shear band thickness is also shown to be dependent on the shape of the sand particles. It was also observed that the scale effects in model footing tests are closely related to sand dilatancy. For a sand layer of finite thickness underlain by a stiff base it is shown that the critical depth of the stiff base is greater for stiffness calculation than that for the bearing capacity calculation. DIC analysis results provided valuable insights to the footing penetration problem and corroborated the theoretical knowledge about the failure modes in sandy soils. It is shown that the failure mechanism extend deeper and wider for sands with angular particles as compared to the sand with rounded particles. DIC analysis also revealed that as the distance between the footing base and stiff layer reduces, the shear bands are more readily formed but their lateral extents are reduced considerably. The high-quality experimental data provided in this dissertation is aimed to be useful to researchers working on the validation of numerical simulations of footing penetration in sands.</p>

Yes / In order to improve the efficiency of the structural lateral resistance system, a new type of Grid tubular-Double Steel Plate (GDSP) concrete composite shear walls is proposed and investigated in this paper. Six test specimens, namely one reinforced concrete (RC) shear wall, three GDSP concrete composite shear walls, one concrete-filled steel tube (CFST) frame, one CFST frame and GDSP concrete composite shear wall combined system were physically tested to failure. The seismic performance of the six test specimens, including hysteresis behavior, ductility, energy dissipation, degradation of stiffness and strength, are recorded and compared. The results show that the GDSP concrete composite shear walls exhibited typical bending failure under low reversed cycle loading, achieving good seismic performance with full hysteresis curve, high bearing capacity, excellent ductility, slow degradation of stiffness and bearing capacity. Under the same axial compression ratio, the yield load of GDSP concrete composite shear wall was about 2.73 times, whilst the peak load was 3.23 times, respectively, of those of RC shear wall. On the other hand, the peak displacement of GDSP concrete composite shear wall was 5 times while ultimate displacement was 3.86 times, respectively, of those of RC shear wall. For GDSP concrete composite shear walls, with the increase of axial compression ratio, the peak load of the new types of concrete composite shear wall increases, but the ductility decreases, gradually. The CFST frame and GDSP concrete composite shear wall can work together co-ordinately. The hysteretic curve of the combined system is fuller, the ductility is improved, the degradation of stiffness and strength are slow when compared with GDSP concrete composite shear wall. Under reversed cyclic loading, the GDSP concrete composite shear wall exhibits low stiffness degradation characteristics and excellent fatigue resistance. / The authors would like to acknowledge the financial support to the work by the Natural Science Foundation of Jiangsu Province, China (BK20201436), the Open Foundation of Jiangsu Province Engineering Research Center of Prefabricated Building and Intelligent Construction (2021), the Science and Technology Project of Jiangsu Construction System (2018ZD047, 2021ZD06), the Science and Technology Project of Gansu Construction System (JK2021-19), the Science and Technology Cooperation Fund Project of Yangzhou City and Yangzhou University (YZU212105), the Science and Technology Innovation Fund of Yangzhou University (2020-65) and the Blue Project Youth Academic Leader of Colleges and Universities in Jiangsu Province (2020).

Yes / In order to promote the utilization of high strength materials and application of prefabricated structures, flexural behaviour of section steel-precast UHPC (Ultra-High performance concrete) slab composite beams prefabricated with bolt shear connectors are numerically simulated by the finite element (FE) software ABAQUS. The model is verified by three prefabricated steel-concrete composite beams tested. Numerical analysis results are in good accordance with experimental results. Furthermore, parametric studies are conducted to investigate the effects of strength of section steel and concrete of precast slab, thickness of section steel, width and height of precast concrete slab, diameters of steel bars and bolt shear connectors. The flexural behaviour of composite beams, in terms of bearing capacity, deflection, ductility and energy dissipation, are compared. The numerical results indicate that the improvement of strength of section steel results in a decrease of ductility, but a significant increase of the ultimate load and energy dissipation. Compared with composite beam made of section steel with thickness of 10 mm, the ultimate load of beams made of section steel with thickness of 14 and 18 mm improve by 29.0% and 58.8%, respectively, the ductility enhance by 2.8% and 8.3%, respectively, and the energy dissipation improve by 8.0% and 12.3%, respectively. With the increase of concrete strength, the ultimate load, deflection and energy dissipation gradually increase. The ductility of steel-UHPC composite beam is the highest, that of steel-HSC composite beam is the lowest. The effect of reinforcement ratio of concrete slab and diameter of shear bolts on the ultimate load of composite beam is limited. Simplified formulae for two different sectional types of proper-reinforced section steel-precast UHPC slab composite beams occurred bending failure are proposed, and the predicted results fit well with the simulated results. The results can be taken as a reference for the design and construction of section steel-precast UHPC slab composite beams.