Column-supported embankments (CSE) enable accelerated construction on soft soils, high performance, and protection of adjacent facilities. The foundation columns transfer embankment and service loading to a competent stratum at depth such that loading on the soft soil can be reduced. This has the beneficial effects of reducing settlement and lateral displacement, and improving stability. Selection of column type depends on the design load, cost, constructability, etc., although unreinforced concrete columns are commonly used. A load transfer platform (LTP) is often included at the embankment base. This is a layer of coarse-grained fill that may include one or more layers of geosynthetic reinforcement. The LTP improves vertical load transfer to columns by mobilizing the shear strength of the LTP fill and the membrane effect of the geosynthetic. The geosynthetic reinforcement also responds in tension to lateral spreading. Herein, lateral spreading is defined as the lateral displacements occurring in response to lateral earth pressures in the embankment and foundation. Excessive lateral spreading can lead to bending failure of the concrete columns, tensile failure of the geosynthetic reinforcement, and instability of the system. Design procedures recommend inclusion of geosynthetic reinforcement to mitigate lateral spreading, with assumptions for the lateral thrust distribution, failure mode, and calculation of geosynthetic tensile capacity. The necessity and sufficiency of these assumptions have not been fully validated. In addition, unreinforced concrete columns have low tensile strength and can fail in bending, but recommendations for calculating column bending moments are not available. This research examines the limitations in CSE lateral spreading design with the goal of advancing fundamental understanding of lateral spreading mechanics. The research was performed using three-dimensional finite difference analyses. Limiting conditions for lateral spreading analysis were identified using case history records, and an undrained-dissipated approach was validated for the numerical analysis of limiting conditions (i.e., undrained end-of-construction and long-term excess pore pressure dissipated). The numerical model was calibrated using a well-documented case history. Additional analyses of the case history were performed to examine the lateral earth pressures in the foundation, column bending moments, and geosynthetic contribution to resisting lateral spreading. A parametric study was conducted to examine the lateral thrust distribution in 128 CSE scenarios. A refined substructure model was adopted for analyzing peak geosynthetic tensions and strains. Lastly, failure analyses were performed to examine the effect of different CSE design parameters on embankment failure height, failure mode, and deformations. The research produced qualitative and quantitative information about the following: (1) the percent thrust resistance provided by the geosynthetic as a function of its stiffness; (2) the geosynthetic contribution to ultimate and serviceability limit states; (3) the change in lateral thrust distribution throughout the embankment system before and after dissipation of excess pore water pressures; (4) the column-soil interactions involved in embankment failure; and (5) identification of two failure modes in the undrained condition. Design guidance based on these findings is provided. / Doctor of Philosophy / Column-supported embankments (CSEs) have been designated by the Federal Highway Administration as a critical technology for new highway alignment projects and widening of existing highways. CSEs enable accelerated construction and high performance in weak soils, which are factors critical to project success. In a CSE, columns are installed in the weak soil, followed by rapid construction of the soil embankment that provides the necessary elevation and foundation for the roadway. The columns transfer most of the embankment and traffic loading to a competent soil stratum at depth. Concrete without steel reinforcement is commonly used to construct the columns, although material selection depends on cost, constructability, expected load, etc. Layers of geosynthetic reinforcement can also be included at the embankment base. The geosynthetics help to transfer loads to the columns and resist excessive movement that could lead to instability. The entire embankment system should be designed for safety and economy. This research was motivated by uncertainties in design to mitigate lateral spreading. Lateral spreading refers to lateral displacements occurring in response to lateral earth pressures in the embankment and foundation. Excessive lateral spreading can lead to failure of the columns, geosynthetic reinforcement, and the entire embankment system. This research aims to advance fundamental understanding of lateral spreading in CSEs and to re-evaluate current design assumptions. Corresponding design guidance is provided.

Increasing interest, from the U.S. Army Corps of Engineers (USACE) and other agencies, in using deep-mixing methods (DMM) to improve the stability of levees constructed on soft ground is driven by the need to reduce levee footprints and environmental impacts and to allow for more rapid construction. Suitable methods for analysis and design of these systems are needed to ensure that the DMM technology is properly applied. DMM shear walls oriented perpendicular to the levee alignment are an effective arrangement for supporting unbalanced lateral loads. Shear walls constructed by overlapping individual DMM columns installed with single-axis or multiple axis equipment include vertical joints caused by the reduced width of the wall at the overlap between adjacent columns. These joints can be made weaker by misalignment during construction, which reduces the efficiency of the overlap. Depending on the prevalence and strength of these joints, complex failure mechanisms, such as racking due to slipping along vertical joints between adjacent installations in the shear walls, can occur. Ordinary limit equilibrium analyses only account for a composite shearing failure mode; whereas, numerical stress-strain analyses can account for other failure modes. Five case studies provided by the USACE were analyzed to evaluate the behavior of levee and floodwall systems founded on soft ground stabilized with DMM shear walls. These identified and illustrated potential failure mechanisms of these types of systems. Two-dimensional numerical stability and settlement analyses were performed for the case studies using the FLAC computer program. The key findings and conclusions for the individual case studies were assessed and integrated into general conclusions about design of deep-mixing support for levees and floodwalls. One of the significant findings from this research was to identify the potential for a partial depth racking failure, which can control design when the DMM shear walls are socketted into a relatively strong bearing layer. The potential for partial depth racking failure is not discussed in the literature and represents a new failure mode identified by this research. This discovery also highlights the importance of adapting suitable methods for analysis and design of these systems to address all potential failure modes. / Ph. D.

When an embankment is to be constructed over ground that is too soft or compressible to adequately support the embankment, columns of strong material can be placed in the soft ground to provide the necessary support by transferring the embankment load to a firm stratum. This technology is known as column-supported embankments (CSEs). A geosynthetic-reinforced load transfer platform (LTP) or bridging layer may be constructed immediately above the columns to help transfer the load from the embankment to the columns. There are two principal reasons to use CSEs: 1) accelerated construction compared to more conventional construction methods such as prefabricated vertical drains (PVDs) or staged construction, and 2) protection of adjacent facilities from distress, such as settlement of existing pavements when a roadway is being widened. One of the most significant obstacles limiting the use of CSEs is the lack of a standard design procedure which has been properly validated. This report and the testing described herein were undertaken to help resolve some of the uncertainty regarding CSE design procedures in light of the advantages of the CSE technology and potential for significant contributions to the Strategic Highway Research Program, which include accelerated construction and long-lived facilities. Twelve design/analysis procedures are described in this report, and ratings are assigned based on information available in the literature. A test facility was constructed and the facility, instrumentation, materials, equipment, and test procedures are described. A total of 5 CSE tests were conducted with 2 ft diameter columns in a square array. The first test had a column center-to-center spacing of 10 ft and the remaining four tests had center-to-center spacings of 6 ft. The Adapted Terzaghi Method of determining the vertical stress on the geosynthetic reinforcement and the Parabolic Method of determining the tension in the geosynthetic reinforcement provide the best agreement with the test results. The tests also illustrate the importance of soft soil support in CSE performance and behavior. A generalized formulation of the Adapted Terzaghi Method for any column/unit cell geometry and two layers of embankment fill is presented, and two new formulations of the Parabolic Method for triangular arrangements is described. A recommended design procedure is presented which includes use of the GeogridBridge Excel workbook described by Filz and Smith (2006, 2007), which was adapted for both square and triangular column arrangements. GeogridBridge uses the Adapted Terzaghi Method and the Parabolic Method in a load-displacement compatibility design approach. For completeness, recommended quality control and quality assurance procedures are also provided, and a new guide specification is presented. / Ph. D.

The advantages of Integral Abutment Bridges (IABs) include reduced maintenance costs and increased useful life spans. However, comprehensive and practical analysis tools for design of IABs have not been developed to account for the impacts of thermal displacements on abutment and foundation components, including the components of mechanically stabilized earth (MSE) walls that are often used around the abutment piling. During this research, over 65 three-dimensional numerical analyses were performed to investigate and quantify how different structural and geotechnical bridge components behave during thermal expansion and contraction of the bridge deck. In addition, separate three-dimensional numerical models were developed to evaluate the usefulness of corrugated steel pipes around the abutment piles. The results of this research quantify the influence of design parameter variations on the effects of thermal displacement on system components, and thus provide guidelines for IAB design, where none had existed before. One of the findings is that corrugated steel pipes around abutment piles are not necessary. One of the most important products of this research is an easy-to-use Excel spreadsheet, named IAB v2, that not only quantifies the impact of thermal displacement in the longitudinal direction, but also in the transverse direction when the abutment wall is at a skew angle to the bridge alignment. The spreadsheet accommodates seven different pile sizes, which can be oriented in weak or strong directions, with variable offset of the abutment from the MSE wall and for variable skew angles. The spreadsheet calculates the increment of displacements, forces, moments, and pressures on systems components due to thermal displacement of IABs. / Ph. D.

<p>Dams that comprise broadly and widely graded glacial materials, such as moraines, have been found to be susceptible to internal erosion, perhaps more than dams of other soil types. Internal erosion washes out fine-grained particles from the filling material; the erosion occurs within the material itself or at an interface to another dam zone, depending on the mode of initiation. Whether or not internal erosion proceeds depend on the adequacy of the filter material. If internal erosion is allowed, it may manifest itself as sinkholes on the crest, increased leakage and muddy seepage once it surfaces, which here is called surfacing internal erosion (i.e. internal erosion in the excessive erosion or continuation phase). In spite of significant developments since the 1980s in the field of internal erosion assessment, the validity of methods developed by others on broadly graded materials are still less clear because most available criteria are based on tests of narrowly graded granular soils. This thesis specifically addresses dams that are composed of broadly graded glacial soils and investigates typical indicators, signs and behaviors of internal erosion prone dams. Based on a review of 90+ existing moraine core dams, which are located mainly in Scandinavia as well as North America and Australia/New Zealand, this thesis will show that not only the filter’s coarseness needs to be reviewed when assessing the potential for internal erosion to surface (i.e., erosion in the excessive or continuing phase); in addition, the grading stability of the filter and the core material as well as non-homogeneities that are caused by filter segregation need to be studied. Cross-referencing between these aspects improves the assessment of potential for internal erosion in dams of broadly graded soils and furthermore it provides aid-to-judgment.</p> / QC 20100715

Atualmente a otimização e redução de custos verificados na fabricação de tubulações está caminhando para um limite. Toda e qualquer modificação no processo produtivo exige grandes investimentos com retorno a prazos cada vez maiores. Assim, a possibilidade de poder contar com técnicas que permitam a redução de esforços sobre tubulações enterradas traz sem dúvida uma importante contribuição. Este trabalho estuda o uso da trincheira como forma de reduzir os esforços que atuam sobre condutos enterrados, utilizando duas séries de ensaios denominados \"A\" e \"B\". Cada série é composta basicamente de quatro combinações diferentes, com variações geométricas da relação de altura relativa (h/B) e largura relativa (b/B). A série B teve a posição relativa (H/B) da camada flexível modificada em relação à série A. Os ensaios realizados no Departamento de Geotecnia da Escola de Engenharia de São Carlos apresentam como resultado uma redução dos esforços da ordem de 44% a 86% em relação ao ensaio de referência montado sem o uso da camada indutora. / Nowadays the optimization and the reduction of costs verified in the pipes production are walking for a limit. All and whatever modification on the productive process demands great investments with larger time return. Thus, the possibility of taking account with techniques that allows reduction efforts on buried pipes bring without any doubt, an important contribution. This work studies the induced trench to reduce the efforts that act over buried conduits, using two series, \"A\" and \"B\", with four treatments each one. The A series is composed with four different combinations. These combinations have geometric variation between relative height (h/B) and relative width (b/B) of flexible layers, were built directly over the trap door. The \"B\" series is composed with the same geometric flexible layer used in series \"A\", and they have their relative position (H/B) modified. The treatments were conducted at the \"Departamento de Geotecnia\" da \"Escola de Engenharia de São Carlos\". The results obtained were a reduction of the 44 to 86% on the efforts in relation to the reference treatment built without the use of an induced layer.

La poliorcétique romaine connut apogée et suprématie sous le Haut Empire, dans un monde antique urbanisé où les guerres ne cessèrent jamais. Elle est bien davantage que le simple art de faire le siège d’une ville ou d’une place forte. Elle comprend tous les modes d’action, violents ou non. La guerre de siège et la défense en font également partie. Pragmatique, le général romain cherchait la conquête au moindre coût et n’utilisait la violence qu’en dernier lieu. L’assaut dans la foulée, très pratiqué, était d’une efficacité redoutable. Il évitait les désagréments d’un siège incertain, techniquement complexe, demandant une logistique considérable, dévoreur d’hommes, de temps et d’argent. Pour toutes ces raisons, le siège en règle était finalement assez peu fréquent. Une fois entrepris, il pouvait requérir, mais sans doute moins souvent qu’on ne le pense, des travaux lourds et complexes, exigeant de l’armée une division du travail poussée. Au combat, la complémentarité et l’efficacité du couple légion/auxiliaires n’a pas été assez soulignée, de même que l’importance du combat interarmes, incluant l’utilisation systématique des appuis, artillerie, archers et parfois frondeurs. L’assaut final semble avoir été assez rare et les dénouements alternatifs fréquents. Le traitement des vaincus dépendait de leur opiniâtreté. Sans pitié pour ceux qui leur résistaient, les Romains étaient assez pragmatiques pour les autres, en fonction des buts recherchés. Enfin, la prise d’une ville, était génératrice de richesses. Elle renforçait la légitimité impériale et le butin, matériel et humain, était un complément non négligeable pour le chef et le soldat. / Roman siege warfare achieved its upmost efficiency and supremacy under the Early Empire in an antique world in which wars were permanent. Siege warfare is far more than the simple art of besieging cities or fortresses. It includes violent and non-violent courses of action. Siege wars and defense are part of it. Pragmatic, the roman general was eager to capture cities at low cost and use of violence came last. Storming assault was frequently employed and very effective. It avoided dangers of an uncertain siege, characterized by technical complexity, an important logistics, potentially high losses, time consuming and requiring huge financial resources. For all those reasons, methodical siege was not a very usual course of action. It sometimes meant, less frequently than expected, heavy siege works, requiring a demanding division of labor. During the battle, the complementarity and efficiency offered by the couple legion/auxiliaries hasn’t been stressed enough. Such is the importance of combined warfare, which systematically included the use of fire support, artillery, archeries and sometimes slingers. Regarding the capture, final assaults appear to have been rare. Alternative conclusions were most of the time the rule. Pitiless with resistant forces, Romans were rather pragmatic with others, depending on the final desired end state on the ground. When overrun, the city was generally a wealth provider. It concurred to strengthen the imperial legitimacy and, bounty, material and humans as well, was an important financial contribution for the general and the soldier.

FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico / A ocupaÃÃo do litoral de Fortaleza, ao longo das duas Ãltimas dÃcadas, apresentou como principal vetor o turismo. Como conseqÃÃncia houve acelerada ocupaÃÃo dessas Ãreas, com a edificaÃÃo de empreendimentos, alÃm da realizaÃÃo de obras com o objetivo de melhor adequar o litoral para as demandas do setor turÃstico, como exemplo o aterro hidrÃulico da praia de Iracema, causando impactos negativos no ecossistema costeiro, como a interferÃncia na dinÃmica das marÃs e a descaracterizaÃÃo da paisagem costeira. Pelo tÃtulo âO licenciamento ambiental e as intervenÃÃes do Poder PÃblico na zona costeira de Fortaleza-CE: consideraÃÃes sobre o aterro hidrÃulico da praia de Iracemaâ, a presente pesquisa tem como finalidade demonstrar a importÃncia do instrumento de licenciamento ambiental para realizaÃÃo de obras pÃblicas, alÃm das privadas, e, conseqÃentemente, a obtenÃÃo de um melhor uso e ocupaÃÃo da orla marÃtima de Fortaleza. A ausÃncia de uma adequada ordenaÃÃo do uso e ocupaÃÃo do solo urbano-litorÃneo tende a maximizar o problema da utilizaÃÃo exacerbada â e, conseqÃentemente, danos - dos recursos ambientais. Por essa razÃo, orientando-se pelo ideal da sustentabilidade nas zonas costeiras das cidades, Ã fundamental que o Poder PÃblico zele pelas normas vigentes e faÃa uso de instrumentos preventivos, como a realizaÃÃo de estudos prÃvios de impactos ambientais e o licenciamento ambiental, onde todos estejam efetivamente integrados e voltados para a manutenÃÃo da qualidade de vida. / The occupation of the costal area in Fortaleza along the last two decades has had touristic trade as the main segment. As a consequence there has been the fast occupation of this area by enterprise buildings besides other construction work aiming to make the coastal area more suitable for the demands of the touristic trade. As an example we mention the praia de Iracema hydraulic embankment (aterro hidrÃulico) that has caused negative impact on the coastal ecosystem such as interference on the dynamic of the tides as well as damage on the characteristics of the coastal landscape. According to the title âEnvironmental licensing and interventions of the Public Power on the coastal area of Fortaleza â CearÃ: considerations on the praia de Iracema hydraulic embankmentâ this research work aims to show the importance of environmental licensing as a means to control the accomplishment of public as well as private construction work and consequently the better occupation of the coastal area along Fortaleza. The lack of an adequate ordering in the use and occupation of the coastal urban area along Fortaleza tends to maximize the problem of its exaggerated use thus causing damage to the environmental resources. It is crucial the development of preventive public policies aiming a better ordering and planning of the use of the coastal urban space allowing the preservation of natural resources and giving more guarantee to the sustainability of the economical activities, mainly tourism. For all these reasons and having in mind the ideal of sustainability of the coastal areas of the cities it is fundamental that the Public Power take good care of the established law and make use of preventive instruments such as the previous study of environmental impactand environmental licensing where all parts be effectively integrated and aiming the maintenance of good living conditions.

In this research, two comprehensive numerical models were developed using ABAQUS/CAE Finite Element (FE) software: 1) geothermal model, and 2) coupled thermo-hydro-mechanical model. In the first model, a purely heat transfer analysis was performed to reproduce the conditions at the site and investigate the subsurface thermal regime beneath the road embankment. The existence of a frozen section (frost bulb) underneath the embankment and its size and location were investigated by the model. The second model concentrated on the mechanical behaviour of the road embankment. Temperature-dependent thermal and mechanical properties were used for all the materials. Model parameters were calibrated using the results of the triaxial and oedometer tests which have been conducted by previous researchers. A fully-coupled and a sequentially-coupled analysis were conducted. The results of the two analyses were compared to each other and to the field measurements. / February 2016

In this study, dynamic response of Akk&ouml / pr&uuml / Dam under earthquake motions is analyzed and the permanent displacements are evaluated. Initially, the critical slip surface of the dam and the corresponding yield acceleration are determined by using the computer program SLOPE. Then, by employing the finite element program SAP2000, static analyses are performed to obtain the mean effective stresses which are used in the determination of dynamic material properties of the dam. Four different scenario earthquakes having a magnitude of 7 are used in the dynamic analyses. Two of those scenarios are taken from European Strong Motion Database and the others are generated by XS artificial earthquake generation program prepared by Erdik (1992). Dynamic analyses of the dam are carried out by the finite element program TELDYN. Permanent displacements of the critical slip surface are calculated by utilizing the Newmark method. Consequently, for an earthquake having a magnitude of M=7 and a peak ground acceleration of 0.20g, the maximum permanent displacement of the dam is found to be 15.90 cm. Furthermore, the permanent displacements of the dam are calculated under base motions having different peak ground acceleration values and it is observed that the rate of increase in the amount of permanent displacements is greater than the increase in the amount of peak ground accelerations.