In this thesis, we produce a rigorous and quantitative analysis of the errors introduced by finite difference schemes into strong constraint 4D-Variational (4D-Var) data assimilation. Strong constraint 4D-Var data assimilation is a method that solves a particular kind of inverse problem; given a set of observations and a numerical model for a physical system together with a priori information on the initial condition, estimate an improved initial condition for the numerical model, known as the analysis vector. This method has many forms of error affecting the accuracy of the analysis vector, and is derived under the assumption that the numerical model is perfect, when in reality this is not true. Therefore it is important to assess whether this assumption is realistic and if not, how the method should be modified to account for model error. Here we analyse how the errors introduced by finite difference schemes used as the numerical model, affect the accuracy of the analysis vector. Initially the 1D linear advection equation is considered as our physical system. All forms of error, other than those introduced by finite difference schemes, are initially removed. The error introduced by `representative schemes' is considered in terms of numerical dissipation and numerical dispersion. A spectral approach is successfully implemented to analyse the impact on the analysis vector, examining the effects on unresolvable wavenumber components and the l2-norm of the error. Subsequently, a similar also successful analysis is conducted when observation errors are re-introduced to the problem. We then explore how the results can be extended to weak constraint 4D-Var. The 2D linear advection equation is then considered as our physical system, demonstrating how the results from the 1D problem extend to 2D. The linearised shallow water equations extend the problem further, highlighting the difficulties associated with analysing a coupled system of PDEs.

Fire is a significant threat to the structural integrity of buildings. Depending on the architecture of the structure and the intensity and duration of the fire event, structural members may lose strength and stiffness eventually leading to collapse whether by flexural buckling or crushing. The focus of this research is on the behavior and fire performance of reinforced-concrete columns under fire conditions. In order to effectively study column performance with differing loading, aggregate and dimensional characteristics under varying time-temperature curves and fire exposures, a numerical model was constructed in Microsoft Excel. The spreadsheet model allowed for complete transparency of the calculations and provided a means to visualize the data in flexible ways. ANSYS and several published column furnace tests were used to benchmark the heat transfer and structural analysis portions of the model. One, three and four-sided fire exposures along with the ASTM E119 fire curve and a natural fire curve were used to study latent heating effects, increasing and decreasing eccentricities, moment magnification, and failure modes. Assessments of column structural capacity were performed in accordance with the provisions of ACI 318. The completed model served as an effective tool for the thesis and is available to help aid students and engineers investigate the design of reinforced concrete columns under fire conditions through integration the heat transfer analyses and the structural evaluations.

Devido ao processo de urbanização sem planejamento adequado, as cidades costeiras sofrem com as inundações e erosão das praias com a elevação do nível do mar e ação de ondas. Entre as estruturas mais utilizadas para proteção de praias destacam-se os quebra-mares segmentados. Para estudar e prever as respostas praiais à presença destas estruturas, podem ser empregados modelos numéricos, capazes de calcular os processos complexos deste ambiente. Este trabalho teve como objetivo o estudo da resposta hidrodinâmica e sedimentar de uma praia com a implantação de quebra-mares segmentados. O modelo hidrodinâmico utilizado é o MIKE21FM acoplado ao modelo de ondas SW e sedimentos ST e SM. Primeiramente, foram impostas condições hidrodinâmicas simplificadas e diferentes arranjos de quebra-mares segmentados. As áreas erodidas e acrescidas após a implantação da obra foram comparadas e priorizou-se minimizar a área erodida. Em seguida, foram considerados os cenários de condições hidrodinâmicas variadas com uma das estruturas. Os resultados são apresentados em termos de altura significativa e potência de onda para 18 casos de condições hidrodinâmicas constantes, as quais foram feitas variar em nível e características da onda. Para a condição hidrodinâmica mais crítica, obteve-se uma redução de 0,4m da altura significativa média e 2kW/m da potência média da onda. Através desses resultados é possível aquilatar a proteção da região da praia da ação das ondas após a implantação da estrutura. Além disso, foram feitas duas simulações com 3 a 4 meses de evolução do fundo em condições hidrodinâmicas reais, com o intuito de apresentar qualitativamente as áreas de erosão e acreção do fundo da praia. Resultados mostraram que a deriva litorânea local tem direção sudeste, para a Ponta da Praia. Foi observada sedimentação no tardoz dos segmentos e na região de sombra e erosão nas áreas entre segmentos e a frente destes. Com isso, este trabalho colabora com o gerenciamento costeiro na região de Santos, apresentando o início de uma pesquisa para uma possível solução para os problemas de inundação e erosão da região da Ponta da Praia. / Erosion and flooding are common problems faced by coastal cities as a consequence of urbanization process without previous planning, with the sea level rise and the wave action. In order to mitigate these problems, shoreline protection structures are constructed along the coastlines, such as segmented breakwaters. Numerical models are tools frequently used in these studies because of its capacity of calculating the complex processes on a coastal environment. This study aim is to present a study based on the hydrodynamic and sediment transport response of a curved beach to the presence of segmented emerged breakwaters. The numerical model used is the MIKE21FM coupled with wave spectral and sediment transport modules. Firstly, constant boundary conditions were applied for the period of one year in order to understand the response of the beach to five different designs of coastal breakwaters. One of these structures were chosen to continue the study based on the area and length of the beach eroded and accreted. Secondly, eighteen different scenarios of wave and water level were applied to the selected structure and the protection of wave action were compared and analyzed. To the most critical hydrodynamic condition, the structure reduced 0,4 m of the mean significant wave height and 2 kW/m of the mean wave power. Finally, two real hydrodynamic conditions were applied and the sediment transport was qualitatively analyzed. Results show that the littoral drift in the studied area is directed to the southeast end of the beach, straight to the Ponta da Praia, without the spur breakwater, the sediment would end inside the navigation channel. Besides that, it shows the sedimentation and erosion patterns at the beach generated by the presence of the breakwater. The sediment is accumulated at the shadow area and at the lee, whereas the erosion is located at the front of the breakwaters and between the segments, as expected. Therefore, this study collaborates with the management of Santos, by presenting herewith a possible solution for the inundation and erosion problems of this area.

This Master´s Thesis studies the applicability of existing numerical model to predict the conditions in the drifts at the mine. Damage mapping, covering the existing production levels, has been carried out to study the condition of the surface support, i.e. shotcrete, mesh and rock bolts to quantify the amount of deformation visible in the tunnels. Irregularities in the floor levels were also mapped. The rock support applied varies between different areas, from only a layer of shotcrete to areas where shotcrete, mesh and cable bolts are applied sequentially. The large amount of support in some regions is required because of high in situ rock stresses in Kemi Mine. The geological conditions are challenging, with large local variation making efficient supporting and damage prediction difficult. Access drifts at the mine have varying service times, on average 6 years, which is a long time in a difficult environment. The results from this work are a mine specific damage classification, used in the mapping to capture the range of damages seen on site. A reoccurrence of same areas showing damages on several production levels is noted. Digitized versions of the damage maps were made and these have been compared to simulation results. The comparisons were made to plots of deviatoric strain, deviatoric stress and total displacement. Based on the work done during this project it can be concluded that the studied parameters have varying levels of agreement with the drifts, both when comparing the levels with each other and the results in the same level between spring and autumn. The best agreement is found with the deviatoric strain increment and the yielded elements. Rock mechanics and geological reasons for the variations seen between the mapping results and the simulations results can be further studied in the future, as can the alternatives for increasing the accuracy through changes in the numerical model or model type used for comparison.

Dados de altura da superfície do mar medidos a partir de satélites altimétricos e saídas de dois modelos de circulação geral dos oceanos (OGCM for the Earth Simulator - OFES e Community Earth System Model - CESM) foram utilizados com o objetivo de verificar se modelos numéricos climáticos reproduzem ondas de Rossby de forma similar à observada em dados altimétricos no Atlântico Sul. Os modelos diferem quanto à forçante, o modelo OFES é forçado com dados do NECP-NCAR enquanto que o modelo CESM é acoplado com modelo atmosférico, de gelo e terrestre. Uma vez que essas ondas dependem da estrutura interna de densidade e da forçante do vento, podemos fazer inferências sobre a adequação desses dois fatores nos modelos à realidade observada pelo altímetro. Uma série de filtros de resposta impulsiva finita 2D (FIR-2D) foi aplicada aos dados de anomalia da altura da superfície do mar com o propósito de detectar as ondas de Rossby e as componentes de onda encontradas nos dados dos modelos foram comparadas com as do altímetro. Os dois modelos são capazes de reproduzir ondas de Rossby e apresentam melhores resultados em baixas latitudes. Porém o modelo OFES apresentou mais dificuldades para reproduzir os parâmetros de onda encontrados no altímetro apresentando diferenças médias de até 68% para a amplitude, 34% para o comprimento de onda e 38% para a velocidade de fase. Em contrapartida as maiores diferenças médias entre os parâmetros de onda calculados a partir dos dados altimétricos e do modelo CESM foram de 32% para a amplitude, 20% para o comprimento de onda e 20% para a velocidade de fase. Além disso, o modelo CESM foi capaz de reproduzir o sinal sazonal com uma correlação média de aproximadamente 0,7 com o sinal sazonal encontrado pelo altímetro em toda a bacia do oceano Atlântico Sul enquanto que o sinal sazonal do modelo OFES apresentou uma correlação média de 0,4 com o sinal encontrado pelo satélite. Estes resultados mostram que os dois modelos reproduzem o fenômeno satisfatoriamente, sendo o CESM melhor que o OFES. A diferença dos resultados deve estar ligada aos aspectos supracitados, especificamente à forçante atmosférica e estrutura de densidade na coluna d\'água nas latitudes ao sul de 20ºS. / Sea surface height data measured from altimetry satellites and outputs of two ocean general circulation models (OGCM for the Earth Simulator - OFES and Community Earth System Model - CESM) were used to determine whether climate numerical models reproduce the Rossby waves in a manner similar to those observed in altimetry record in the South Atlantic. The models differs in the forcing, OFES is forced with NCEP-NCAR data while CESM is coupled with atmospheric model, ice and land model. Because these waves depend on the internal density structure and wind forcing, we can make inferences about the suitability of these two factors in the models in comparison with the altimetry data used as a reference. A series of finite impulse response band-pass filters (FIR-2D) was applied to isolate the westward propagating signals corresponding to Rossby waves in the altimeter. Both models are able to reproduce Rossby waves and show better results in low latitudes. However, the OFES model presented more difficulty to reproduce the wave parameters found in altimeter with differences of up to 68% for amplitude, 34% for the wavelength and 38% for phase velocity. By contrast the greatest differences between the wave parameters computed from the altimeter data and the CESM model were 32% for amplitude, 20% for the wavelength and 20% for phase velocity. Furthermore, the CESM model was capable of reproducing the seasonal signal correlation with an average of approximately 0.7 with altimeter\'s seasonal signal found throughout the South Atlantic basin, while the OFES\'s seasonal signal showed an average correlation 0.4 with the signal found by the satellite. These results indicate that both models can reproduce the phenomenon satisfactorily, the CESM better than OFES. The difference between the results should be related with the aspects cited above, specifically with the atmospheric forcing and the density structure in the water column in latitudes southern then 20ºS.

O reparo em dutos defeituosos é previsto por normas e literatura, porém existe grande espaço para definição dos parâmetros ideais para aplicação prática e avaliação do desempenho destes reparos em fadiga. O presente trabalho tem por objetivo a definição dos parâmetros ideais para aplicação de reparos eficientes do tipo dupla calha sem solda circunferencial e com carregamento externo em escala real em dutos com defeitos de mossa com cava. O reparo é baseado na instalação de duas calhas concêntricas ao duto a ser reparado, preenchendo-se o defeito com resina e aplicando carga de compressão através de atuadores hidráulicos com correntes a fim de induzir tensões compressivas na região do defeito e, por fim, as calhas são unidas longitudinalmente pelo processo de soldagem. Para este trabalho, foi realizada uma modelagem numérica utilizando o método de elementos finitos de modo a simular a reprodução do defeito, ensaios de fadiga sem reparo, parâmetros para aplicação do reparo, ensaios de fadiga com reparo e, por fim, ensaio hidrostático. O procedimento proposto foi a reprodução do defeito, primeiramente o duto foi deformado com uma esfera metálica, de modo a formar uma mossa de profundidade igual a 6 % do diâmetro externo e, em seguida, a cava foi usinada com a utilização de um disco abrasivo. Após a produção do defeito, três amostras foram ensaiadas em fadiga, de modo a produzir uma amostra de referência sem reparo a ser comparada com os corpos de prova com reparo. O reparo dupla calha foi aplicado em duas amostras com defeito, sendo essas então submetidas a ensaios de fadiga. Esses ensaios indicaram que ambas as amostras resistiram a um número de ciclos correspondentes a 100 anos de vida em serviço. Por fim, as amostras reparadas após o ensaio de fadiga foram submetidas a ensaios hidrostáticos até a ruptura, a fim de avaliar a vida remanescente. Ambos os dutos romperam fora da região reparada, com uma pressão 2,1 %, menor que a pressão calculada analiticamente. Como principal resultado, foram obtidos parâmetros ideais para aplicação do reparo dupla calha em dutos com defeito tipo mossa com cava. Os resultados experimentais mostram convergência em relação aos dados do modelo numérico, provando que a modelagem por elementos finitos pode ser uma ferramenta útil no desenvolvimento deste tipo de trabalho. / Defective duct repairs are envisaged by norms and by the literature, yet there is enough space left to define ideal parameters for practical application and performance evaluation of these fatigue repairs. This work’s objective is to define the ideal parameters for the application of efficient repairs in double spouts without circumferential welding and real scale external loading in ducts with dent and gouge defects. The repair is based on the installation of two concentric spouts in the duct, filling the defect with resin and applying compression loading through hydraulic actuators with currents to induce compressive stresses in the defective area. Afterwards, the spouts are united lengthwise through the process of welding. To develop this work, we conducted a numerical modelling by using the finite element method to simulate the reproduction of the defect, as well as fatigue tests with no repairs, parameters for the application of repairs, fatigue tests with repairs, and finally a hydrostatic test. The proposed procedure was the reproduction of the defect. At first the duct was deformed with a metallic sphere, to form a dent whose depth was equal to 6 % of the external diameter and, subsequently, the gouge was machined with the help of an abrasive disk. Following the production of a defect, three samples were tested in fatigue to produce a reference sample without repair which would be compared to the samples with repairs. The double spout repair was applied in two samples with defects, which were then subjected to fatigue tests. These tests showed that both samples resisted to a number of cycles corresponding to a 100-year use lifespan. At last, the samples repaired after fatigue tests were subjected to hydrostatic tests until rupture, in order to evaluate their remaining lifespan. Both ducts ruptured outside of the repaired region, with a stress rate of 2.1 %, lower than the stress calculated analytically. The main result of this study was obtaining ideal parameters for the application of double spout repair in ducts with dents and gouge defects. The experimental results show convergence in relation to the numerical model data, proving that finite element modelling can be a useful tool when conducting this kind of work.

O trabalho apresentado tem como finalidade analisar os sistemas de ancoragem utilizados na fabricação de End Fittings (EF), através de ensaios de dois sistemas de ancoragem alternativos aos utilizados atualmente na indústria. Além disso, é apresentado o desenvolvimento de um modelo de elementos finitos (MEF) que permite a reprodução do comportamento durante o processo de pullout da ancoragem com melhor desempenho. A caracterização dos materiais envolvidos no sistema de ancoragem foi necessária para o desenvolvimento do modelo numérico. Desta forma, o modelo numérico conta com as propriedades elásticas e plásticas dos materiais, fator que influencia o comportamento do sistema assim como os valores de carga necessários para o arrancamento. A comparação das ancoragens propostas foi realizada a partir dos valores de força obtidos por meio de um teste de arrancamento, chamado de pullout. Para isto, arames da armadura de tração de uma linha flowline de 2,5 polegadas foram conformados de acordo à geometria das ancoragens propostas e embebidas em resina epóxi tentando, desta forma, representar de forma simplificada parte do sistema de ancoragem utilizado nos EF. O desempenho das ancoragens foi analisado a partir das curvas de força em função do deslocamento, nas quais se analisou a força máxima de pullout (força máxima de arrancamento), o deslocamento para força máxima de pullout e o valor de rigidez do sistema. Finalmente depois de selecionada a ancoragem com melhor desempenho, os valores experimentais foram comparados com os valores obtidos do modelo numérico, mostrando uma boa aproximação com valores de erro relativo para a força máxima de pullout e rigidez de -1% e 8%, respectivamente. Por fim, propõe-se como trabalho futuro a continuação nos estudos experimentais de pullout com o objetivo de aprofundar o conhecimento sobre os parâmetros que mais influenciam nestes sistemas, através da utilização de novas geometrias e materiais, assim como a normalização do processo de preparação e ensaio das amostras. / The work aims to analyze the anchoring systems used in manufacturing of flexible pipe End Fittings (EF) through the tests of two alternative anchoring systems different of the currently used in the industry. In addition, it is presented the development of a finite element model (MEF) that allows to reproduce the behavior during the pullout process of the anchoring system with the better performance. The characterization of the materials involved in the anchoring system was necessary for the development of the numerical model. In this way, the numerical model include the elastic and plastic properties of materials, factor that influence the behavior of the system as well as the force values needed for the pullout. The comparison of the proposed anchoring systems was performed from the force values obtained through a pullout test. For this, the armor wires of a flowline flexible pipe with a bore of 2.5-inch were conformed according the geometry of the anchoring systems proposed and then were fixed in epoxy resin, trying in this way to represent a simplified form of the anchoring system used in EF. The performance of the anchoring systems was analyzed from the force-displacement curves. The maximum pullout force, the offset for maximum strength of pullout and the stiffness value of the system were used for the analysis. Finally, after selected the anchoring system with better performance, the experimental values were compared with the values obtained from the numerical model. The results showed a good approximation, with a relative error for the maximum pullout force and stiffness of -1% and 8% respectively. As proposal for future works, the author proposes to continue with the experimental studies of pullout in order to enhance the knowledge about the influential parameters in these systems, through the use of new geometries and materials, as well as the standardization of the test samples preparation.

A aplicação de modelagem numérica para análise acidentes envolvendo derrames de óleo se tornou uma das principais ferramentas para o estudo deste tipo de impacto ambiental, auxiliando na previsão do deslocamento e permitindo maior eficácia nas formas de atuação nos processos de contingência do deslocamento da mancha. Estes pressupostos dão impulso ao desenvolvimento de pesquisa aplicada neste caso específico de estudo, ou seja, de modelação hidrodinâmica no Canal de São Sebastião em vários cenários através da utilização do módulo hidrodinâmico do software MIKE 21 da DHI, e da avaliação dos resultados gerados pela simulação através de comparação com o acompanhamento de eventos reais de espalhamento de manchas de óleo em acidentes antigos e com uma imagem de satélite simultânea a um derramamento. Foram avaliados sete eventos distintos onde ocorreram vazamentos de óleo no Canal de São Sebastião e a eles comparados às simulações hidrodinâmicas geradas pelo modelo em diferentes condições ambientais. Os resultados obtidos mostram que o deslocamento da mancha de óleo está condicionado preferencialmente pelo regime de ventos, estando bem correlacionados com os padrões hidrodinâmicos encontrados. A partir das diferentes situações apresentadas nas simulações, é possível estimar o sentido do deslocamento em acidentes futuros, dando subsídios nas ações de contenção dos efeitos deste tipo de acidente. / The application of numeric models for analysis of oil spill in the coastal environments becomes one of the most important ways to understand the behavior of the oil in this case of impact, giving subsides to the prediction of the displacement of the patches and allowing best efficiency in the control of the extension of the impact agent. These assumptions give thrust to the development of applied research in this work, which is defined by the knowledge of the different hydrodynamic conditions that compose the oceanographic structure in the São Sebastião Channel, by the utilization of the software MIKE 21 of the DHI (Danish Hydrodynamic Institute) and the comparison with historic cases of spill described in the literature. A satellite image was processed showing the real conditions of the spill, considering the physic-chemical changes and compared with the other data improve the evaluation process. Seven oil spills were studied and compared to the simulations, and there were generated six scenarios in different environmental conditions. The results show that the most important forcing of the environmental conditions of the oil patch is the wind, and the simulations agree well with the real processes. The hydrodynamic module of Mike 21 reveals an applicable tool for this kind of studies, giving sufficient information to reduce the impact of oil spill improving the oil spill contention.

This dissertation investigated the physical and biogeochemical processes affecting the source, fate, and transport of sediment, carbon, and nitrogen within a highly-coupled fluviokarst system. Elemental and isotopic datasets were collected at surface and subsurface locations for both dissolved and particulate contaminant phases, new methodology regarding data collection was presented to the karst research community, an in-cave sediment transport model coupling physical transport with elemental and isotopic mass balances of carbon and nitrogen was formulated, pathway and process control on nitrate leaching from agricultural karst watersheds was assessed, and nitrate mobilization and fractionation were modeled using high frequency storm sampling and long-term low-flow sampling. Data and modeling results indicate that phreatic karst conduits are transport-limited during hydrologic events and experience subsurface deposition of labile, storm-injected sediment which is subsequently decomposed by heterotrophic bacteria. An estimated 30% of the organic carbon associated with sediment is decomposed during transport in the subsurface karst. Concentrations of nitrate in subsurface waters are consistently 50% greater than surface inputs suggesting an additional source of subsurface nitrate. Further modeling of nitrate leaching indicates that quick-flow water sources dilute nitrate concentrations and slow-flow (epikarst and phreatic) sources account for approximately 90% of downstream nitrate delivery. Field sampling of extreme events highlights the physical transport and delayed release of high nitrate concentrations by intermediate karst pathways, which is likely associated with a transition from epikarst to soil drainage during storm recession. Modeling of sediment carbon and nitrogen within the karst SFGL supports the idea that the cave sediment bed experiences hot spots and hot moments of biogeochemical activity. Sediment nitrogen tracing data show a significant increase in δ15NSed at the spring outlet relative to karst inputs indicating the potential for isotope fractionation effects during dissolved N uptake by cave biota. Dissolved nitrogen stable isotopic composition shows a significant downstream decrease in δ15NNO3 within the conduit, likely associated with nitrification. Data and modeling results of sediment, carbon, and nitrogen emphasize the role of multiple pathways, turbulent transport, and in-conduit transformations in controlling contaminant flux from karst watersheds.

In urban areas, vibrations generated by pile driving often affect the neighboring properties vulnerable to ground shaking. These vibrations may cause damage to surrounding structures either by shaking the ground or by causing settlement of the soil beneath foundations in the proximity of pile driving. It is important to distinguish between the conditions under which the vibrations will cause damage and those under which vibrations are tolerable. The numerical studies on the analysis of pile driving have mostly focused on assessing the driving efficiency and the bearing capacity of dynamically loaded piles. A limited number of studies included the study of ground vibrations due to pile driving and its effects on adjacent structures. However, the factors affecting the ground vibrations in soils such as the nonlinear constitutive behavior of soil, soil-pile interaction and penetration depth of the pile have not been clearly identified. The objective of this research is to implement a numerical method to simulate dynamic loading of a single pile, and study the factors influencing the stress wave propagation in the soil surrounding the pile. The thesis is comprised of two main analyses: (1) the static analysis of a pile in which the phenomenon of static consolidation is studied, and (2) the dynamic analysis of a pile in which pile driving and ground vibrations are studied. In the static analysis, the load capacity of a single pile is investigated. The results from the finite element method are compared with widely recognized theoretical methods. The theoretical methods that are used to estimate the end bearing capacities are: (1) General Formula, (2) Vesic's Method, (3) Janbu's Method, (4) Meyerhof's Method, and (5) Coyle & Castello's Method. The estimation of skin friction resistance (shaft capacity) of single piles is performed using the (1) Alpha method, (2) Beta method, and (3) Lambda method. Two numerical applications are performed to predict the load capacity of single piles in normally consolidated clays. It is observed that the model with no slippage at the interface predicts almost twice as much load capacity as the model with interface. In regards with the end bearing capacities, Coyle & Castello's method is found to be most conservative followed by the finite element method, the Janbu's method, the Meyerhof's method, and finally the Vesic's method. In respect to skin friction resistance, the finite element is found to be the most conservative method, followed by the Beta, the Lambda, and the Alpha method. In the dynamic analysis, the amplitudes of ground vibrations are investigated based on the variation of: (1) the soil type, (2) the pile embedment length and (3) the released hammer energy. In the first analysis, five types of soils - loose and dense sands and, soft, medium stiff, and stiff clays - are modeled. The highest vibration amplitude is calculated for the loose sand with a peak particle velocity (PPV) of 10.0 mm/s followed by the dense sand with a PPV of around 4.0 mm/s. Among the clay types, the vibrations are higher for the stiffer clay in the near field, which is 9 m (half a pile length) or less away from the pile. In the second analysis, three different embedment lengths - full, half, and quarter pile length - are modeled. It is found that the quarter embedded piles produce greater vibration amplitudes as compared to the half and fully embedded piles. Larger amplitudes of vibrations are encountered on the ground surface for shorter pile embedment lengths. In the third analysis, three different impact forces consisting of 2,000 kN (F), 6,000 kN (3F) and 10,000 kN (5F) are applied on the pile head. It is concluded that increase in hammer energy causes increase in the peak particle velocities.