No / Laboratory scale model slopes reinforced with waste carpet fibers were made in a rigid tank with dimensions of 800 mm x 300 mm x 500 mm. Bearing capacities of the strip footing rested on non-reinforced and fiber-reinforced model slopes with 1%, 3% and 5% fiber content were compared at 20% footing displacement ratio. The influence of location of footing on the bearing capacity was studied with placing the footing at different edge distances from the crest of the footing (i.e., 150 mm, 100 mm and 0). Suction probe sensors were installed at appropriate locations on the rear side of the model slope to measure the pore-water pressure generated due to the footing pressure. Results showed that fiber reinforcement increased the bearing resistance of the model slopes significantly. Inclusion of 5% fiber increased the bearing resistance by 271% compared to that of non-reinforced model slope at the footing edge distance ratio of 3. The location of footing was found to affect the load-carrying capacity of the fiber-reinforced model slope. The increase in the edge distance ratio of the footing increased the load-carrying capacity of the model slope.

Submitted by Fábio Visnadi Prado Soares null (fvps@hotmail.com) on 2018-02-28T12:38:57Z No. of bitstreams: 1 Dissertação - Soares, F V P - 2017 - VF - REPOSITORIO.pdf: 6006217 bytes, checksum: c8b6c04c1ed994f7a112e592011d919b (MD5) / Approved for entry into archive by Maria Marlene Zaniboni null (zaniboni@bauru.unesp.br) on 2018-02-28T17:41:25Z (GMT) No. of bitstreams: 1 soares_fvp_me_bauru.pdf: 6006217 bytes, checksum: c8b6c04c1ed994f7a112e592011d919b (MD5) / Made available in DSpace on 2018-02-28T17:41:25Z (GMT). No. of bitstreams: 1 soares_fvp_me_bauru.pdf: 6006217 bytes, checksum: c8b6c04c1ed994f7a112e592011d919b (MD5) Previous issue date: 2018-01-26 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O comportamento dos solos não saturados é um tema amplamente estudado, tanto por meio de ensaios de laboratório quanto de campo. Fenômenos como o colapso dos solos são relativamente bem explicados pelos modelos elastoplásticos existentes, dos quais o Modelo Básico de Barcelona é um dos mais utilizados e difundidos no meio acadêmico. Apesar dos avanços obtidos, ainda existe certa escassez de estudos que comparem o comportamento previsto por tais modelos a resultados de situações reais de engenharia. Esta pesquisa teve como objetivo simular numericamente resultados de recalques devidos a carregamentos e inundação de provas de carga em placa e de protótipos de sapata construídas sobre solo natural e compactado em cava. Com os resultados buscou-se analisar a eficiência da técnica de compactação para mitigar o problema do colapso do solo. Para isso, ensaios de compressão triaxial e edométricos com sucção controlada, bem como ensaios de curva de retenção e condutividade hidráulica foram realizados para determinação dos parâmetros constitutivos hidráulicos e mecânicos do solo natural e compactado que foram utilizados no programa Code_Bright para simulação numérica dos resultados de campo. Os resultados demonstraram a capacidade do modelo em reproduzir o comportamento do solo no campo. Demonstraram também que o uso da compactação do solo que preconiza compactar em cava uma camada de espessura equivalente à largura da sapata é viável para redução da colapsibilidade, mas depende do nível das tensões atuantes nas fundações e da tolerância aos recalques. Tensões propagadas para a camada de solo natural superiores à tensão de pré-adensamento do solo natural saturado provocarão recalques por colapso quando o solo for umedecido. / The behaviour of unsaturated soils is a widely studied theme around the world, both by utilising laboratory and field tests. Phenomena like soil collapsibility are relatively well explained by the existing elastoplastic models, among which the Barcelona Basic Model is the most widely used in the academic field. Despite the recent advances, there is still a scarcity of papers that compare the behaviour predicted by constitutive models and results of real engineering problems. This research aims to numerically simulate the results of settlement due to loading and wetting of load tests built both on undisturbed and compacted soil. The results were analysed in order to study the efficacy of the soil compaction technique in mitigating soil collapse. Suction controlled triaxial compression and oedometer tests, as well as soil water retention curve and hydraulic conductivity experiments were conducted to determine the hydraulic and mechanic parameters used in the software Code_Bright to numerically simulate field results. The results highlight the capability of the model in reproducing the analysed field behaviour. They also show that the technique that involves compaction of the soil equal to the footing’s width is viable to reduce its collapsibility, but its efficacy will also depend on the tensions applied on the foundation and on the tolerable settlement values. Tensions that are propagated to the natural soil layer that are higher than its preconsolidation stress will cause collapse settlements and wetted.

Due to close proximity of different civil engineering structures, the ultimate bearing capacity and failure pattern of adjoining footings/anchors are often influenced by their mutual interference. The present thesis is an attempt to examine the interference effects on the ultimate failure loads and the elastic settlements for a group of closely spaced strip footings and anchors. In this thesis, a new experimental setup has been proposed to examine the response of interfering strip footings and strip anchors subjected to vertical loads but without having any eccentricity. Through out the investigation, it has been assumed that the magnitudes of loads on all the footings/anchors at any stage of settlement remain exactly the same. Unlike the existing experimental works of the previous researchers reported in literature, in the proposed experimental setup, there is no need to use more than one footing/anchor. As a result a much smaller size of the tank, in which the soil sample needs to be prepared, is required. In the proposed setup, it has been attempted to satisfy the boundary conditions existing along the vertical planes of symmetry midway between any two adjoining footings/anchors. To satisfy the governing boundary conditions, along the planes of symmetry, the interface friction angle is kept as small as possible, with the employment of a very smooth high strength glass sheet, and the associated horizontal displacements are made equal to zero. For two interfering footings/anchors case, only single plane of symmetry on one side of the footing needs to be modeled. On the other hand, for an infinite number of multiple footings/anchors, two vertical planes of symmetry on both the sides of the footing need to be simulated in the experiments. The proposed experimental setup is noted to yield reasonably acceptable results both for the cases of interfering footings and interfering anchors. The magnitudes of ultimate failure loads for the interfering footings/anchors are expressed in terms of the variation of the efficiency factor ( ξγ) with respect to changes in the clear spacing(s) between the footings/anchors; wherein, an efficiency factor is defined as the ratio of the magnitude of the failure load for an intervening strip footing/anchor of a given width to that of an isolated strip footing/anchor having exactly the same width. From the experiments, the values of the efficiency factors are obtained for a group of two and an infinite number of multiple strip footings/anchors. The effect of two different widths of the footing/anchor on the magnitudes of the failure load is also studied. It is noted that for a group of two and infinite number of multiple footings, the magnitude of the ultimate failure load for an interfering footing becomes always greater than that for a single isolated footing. For the case of two footings, the value of ξγ becomes maximum corresponding to a certain critical s/B between two footings. At a given spacing, the value of ξγ is found to increase further with an increase in the value of φ. It is observed that, for a group of an infinite number of equally spaced multiple strip footings, the magnitude of ξγ increases continuously with a decrease in s/B; when the clear spacing between the footings approaches zero, the magnitude of ξγ tends to become infinity. The value of ξγ associated with a given s/B for the multiple footings case is found to become always greater than that for a two footing case. The effect of s/B on ξγ is found similar to that reported in theories in a qualitative sense. The value of ξγ at a given s/B associated for B = 4 cm both for two and multiple footings is found to become smaller as compared to that with B = 7 cm. In contrast to a group of interfering footings under compression, the magnitude of ξγ in the case of both two and multiple interfering anchors decreases continuously with a reduction in the value of s/B. For given values of s/B and embedment ratio ( λ = d/B ), the values of ξγ for the case of multiple anchors are found to be always lower than those for the case of two anchors; d = depth of the anchor. In comparison with the available theoretical values from the literature, the values of ξγ are found to be a little lower especially for smaller values of s/B. The comparison of the present experimental data with that reported from literature reveals that the interference of strip anchors will have relatively more reduction in the uplift resistance on account of interference as compared to a group of square and circular anchors; the present experimental data provides relatively lower values of ξγ as compared to the available experimental data (for square and circular footings). The value of s/B beyond which the response of anchors becomes that of an isolated anchor increases continuously with an increase in the value of λ. The magnitude of ξγ for given values of s/B and λ associated for B = 4 cm is found to become slightly greater as compared to that with B = 7 cm. Both for the cases of interfering footings and anchors, the ratio of the average ultimate pressure with the employment of the rough central plane (glass sheet glued with a sand paper) to that with the smooth central plane, is found to increase with (i) a decrease in the value of s/B, and (ii) an increase in the value of φ. The finite element analysis, based on a linear elastic soil-constitutive model, has also been performed for interfering footings and anchors to find the effect of interference on elastic settlements. The computations have revealed that for both the footings and anchors, a decrease in the spacing between the footings leads to a continuous increase in the magnitudes of the settlements. The increase in the settlement due to the interference becomes quite substantial for an infinite number of footings/anchors case as compared to two footings/anchors case. The effect of the Poisson’s ratio on the results is found to be practically insignificant.

The master’s thesis focuses on suitable design of an ecoduct on the highway D1 near Jihlava. It includes a structural analysis of reinforced concrete strip footings and wooden beams in all phases of construction. The material of the main bearing system is glued laminated timber GL24h. An important part of three-jointed ecoduct wooden arched beams is well-chosen isolation.

<p>  </p> <p>Knowledge of the displacement and deformation fields beneath foundation elements obtained from carefully executed experiments is required to validate state-of-the-art numerical simulations, which in turn enable the development of better foundation design methods. This dissertation presents the results of an experimental program in which load tests were performed on model footings in a half-cylindrical calibration chamber with a transparent viewing window across its diameter. The digital image correlation (DIC) method was used to obtain the strain and displacement fields in the soil from digital images taken during the tests. Tests performed on both smooth and rough footings show a significant dependence of resistance on footing base roughness, with the DIC results providing insight into the reasons for that dependence. The experimental bearing capacity results are used to validate a previously proposed method in which an equivalent friction angle is used for calculation of the bearing capacity of footings in sand.</p> <p>Schmertmann's method is one of the traditional methods for estimating the settlement of axially loaded footings in sand using cone penetration test (CPT) data. The method was developed for footings placed on the surface of a single, uniform sand layer; it assumes a depth of influence below the footing base within which most of the soil deformations take place and an influence diagram to quantify the influence factor as a function of depth. However, the literature contains limited information on the strain influence diagrams for footings on layered sands, and, as a result, there is no way to accurately account for the effect of sand layering on footing settlement. In this study, Schmertmann's approach for calculating the strain influence factor is modified to account for the effect of two sand layers with varying thickness and relative density. Penetration experiments were performed using a half-square model footing (width <em>B</em> = 90 mm) placed on the surface of both single and two-layered (dense over medium-dense and medium-dense over dense), air-pluviated, silica sand samples prepared inside a half-cylindrical calibration chamber designed for digital image correlation (DIC) analysis. The test results indicate that both the thickness and relative density of the top sand layer (the layer in contact with the footing base) affect the parameters of the strain influence diagram. For dense sand over medium-dense sand, the depth to the peak strain influence factor varies with the thickness of the dense layer; however, when the thickness of the dense layer is 1.5<em>B</em> or greater, the strain influence diagram is similar to that obtained for a single, uniform sand layer. In contrast, for medium-dense sand over dense sand, the peak value of the strain influence factor varies with the thickness of the medium-dense layer up to a value of 1<em>B</em>. Based on the results obtained in this study, new strain influence diagrams are proposed for settlement calculation of square footings on two-layered sand profiles. The proposed method for estimation of footing settlement in layered sand is validated against measured data obtained from a full-scale, instrumented footing load test reported in the literature. </p> <p>The expressions for the shape and depth factors available in the literature for bearing capacity calculation are mostly empirical and are based on results obtained using limit analysis or the method of characteristics assuming a soil that is perfectly plastic following an associated flow rule. This study presents the results of an experimental program in which load tests were performed on model strip and square footings in silica sand prepared inside a half-cylindrical calibration chamber with a transparent visualization window. The results obtained from the model footing load tests show a significant dependence of footing penetration resistance on embedment depth. The load test results were subsequently used to determine experimentally the shape and depth factors for model strip and square footings in sand. To obtain the displacement and strain fields in the sand domain, the digital image correlation (DIC) technique was used to analyze the digital images collected at different stages during loading of the model footing. The DIC results provide insights into the magnitude and extent of the vertical and horizontal displacement and maximum shear strain contours below and around the footing base during penetration.</p> <p>The loading of a footing in sand generates substantial shear bands as a mechanism for failure develops with the formation of slip surfaces. The interaction of sand particles in the shear band governs its constitutive response to loading. This study provides the results of loading experiments performed under different conditions on half-square model footings (width <em>B</em> = 90 mm) in dense air-pluviated silica sand samples prepared in a half-cylindrical calibration chamber equipped with an observation window that allows collection of images of the sand domain during testing. Two sands (Ottawa sand and Ohio Gold Frac sand) with different roundness (angularity) were used to perform these experiments. The digital image correlation (DIC) technique was used to obtain the incremental strain fields in the sand domain. The zero-extension line (ZEL) concept was then used to study the shear strain localization process and to obtain the orientation of the shear bands from analysis of the incremental strain fields. The results show that sand particle morphology, footing surface roughness, load eccentricity, and depth of embedment of the model footing have an impact on the dominant shear band patterns that develop below the model footings, and, as a result, all of these factors affect the unit bearing capacity of footings. The estimated thickness <em>t</em>s of the shear band from the experiments is approximately 6<em>D</em>50 for Ottawa sand and approximately 8<em>D</em>50 for Ohio Gold Frac sand. </p>

Master’s thesis is based on analysis and design of a load bearing structure of an apartment block. This structure is supported with a strip footing made of reinforced concrete. The above-ground part of designed structure consists of brick masonry. Floors are constructed of carrying plates. These plates are made of reinforced concrete and precast boards (prestressed concrete). Individual levels are connected with monolithic concrete staircases. The thesis also deals with relevant drawing documentations for chosen parts of construction.

Master’s thesis is based on analysis and design of a load bearing structure of an mountains hotel. Mountain hotel schould be realized in the village Vernirovice in Šumperk district. The proposed structure is formed 4th floors. In 1.NP is a restaurant, a sports and wellness center. In 2.NP in the right side is situated the swimming pool. In 2 to 4 floor are located rooms. This structure is supported with a strip footing made of reinforced concrete. The main load-bearing elements in the vertical direction are in 1.NP reinforced concrete walls and columns, the upper floors bearing masonry walls of ceramic blocks THERM. The inner support walls are 300 mm thick, outside support walls are 400 mm thick. Floors are constructed of carrying plates with girders above the larger openings. These plates and girders are made of reinforced concrete. In the 2 floor are beams with the span of 8,8 m. These girders are designed of prestressed concrete cause the large loads. Individual levels are connected with monolithic concrete staircases. Around the middle of the building is a monolithic reinforced concrete elevator shaft. The highest elevation above grade level is 16 m. The thesis also deals with relevant drawing documentations for chosen parts of construction.The building is located in the ski area VI and IV wind areas.