Exploring the effects of stress history on the drained and undrained cyclic behaviour of granular materials.

This paper presents the results of 3D DEM simulations of granular materials subject to cyclic loading. While both the drained and undrained conditions are considered, the effects of depositional history and consolidation stress history on the stress-strain response are specifically evaluated. It is demonstrated that the different stress histories have a significant effect on soil response and that such effects can be attributed to differences in the initial particle arrangement (fabric).

Dimensionamento de uma ponte metálica de suporte de uma tela transportadora de inertes a utilizar numa instalação industrial

Trabalho de Projeto para obtenção do grau de Mestre em Engenharia Civil na Área de Especialização em Estruturas

Projeto de estabilidade de um edifício para uma sala elétrica em betão armado e estrutura metálica

Trabalho de Projeto para obtenção do grau de Mestre em Engenharia Civil na Área de Especialização Estruturas

Sur les ondes T des séismes des Philippines enregistrées à Nhatrang

According to the authors, T waves recorded at Nhatrang from Philippine Islands earthquakes may present 3 important phases: F and G, T. and M. If h is the depth of the earthquake, a and b the land paths of T waves respectively near the epicenter and the station, these phases may be noted as: ph-Sofar-SV sub(b) for F and G; P sub(a)-Sofar-SV sub(b) for T sub(2) and problably S in sediments, for M. Sofar waves velocity in China sea, between Philippine and Vietnam, has been determined as to be: 1.48 ± 0.03km

Tectonic expression of an active slab tear from high-resolution seismic and bathymetric data offshore Sicily (Ionian Sea)

Subduction of a narrow slab of oceanic lithosphere beneath a tightly curved orogenic arc requires the presence of at least one lithospheric scale tear fault. While the Calabrian subduction beneath southern Italy is considered to be the type example of this geodynamic setting, the geometry, kinematics and surface expression of the associated lateral, slab tear fault offshore eastern Sicily remain controversial. Results from a new marine geophysical survey conducted in the Ionian Sea, using high-resolution bathymetry and seismic profiling reveal active faulting at the seafloor within a 140 km long, two-branched fault system near Alfeo Seamount. The previously unidentified 60 km long NW trending North Alfeo Fault system shows primarily strike-slip kinematics as indicated by the morphology and steep-dipping transpressional and transtensional faults. Available earthquake focal mechanisms indicate dextral strike-slip motion along this fault segment. The 80 km long SSE trending South Alfeo fault system is expressed by one or two steeply dipping normal faults, bounding the western side of a 500+ m thick, 5 km wide, elongate, syntectonic Plio-Quaternary sedimentary basin. Both branches of the fault system are mechanically capable of generating magnitude 6-7 earthquakes like those that struck eastern Sicily in 1169, 1542, and 1693.

Reforço sísmico de estruturas em adobe

A construção em alvenaria de adobe tem um vasto património a nível mundial. É possível encontrar construção em terra no nosso território, sendo que a técnica particular do adobe foi amplamente utilizada na região de Aveiro durante o século XIX até meados do século XX. Devido à tradição e valor patrimonial da construção em alvenaria de adobe, diversos trabalhos têm vindo a ser desenvolvidos no departamento de Engenharia Civil da Universidade de Aveiro, perspetivando um aprofundar de conhecimentos acerca deste tipo de construção. A vulnerabilidade sísmica das construções em alvenaria de adobe fez com que surgissem vários estudos para caracterização sísmica das mesmas, sendo que, recentemente, foi levada a cabo a realização de um ensaio cíclico, simulando os efeitos de um sismo, num modelo de adobe à escala real, construído no laboratório do departamento de Engenharia Civil da Universidade de Aveiro. A presente dissertação tem como objetivo estudar formas de reparação e reforço sísmico de estruturas em adobe. Para isso foi reparado e reforçado o modelo previamente ensaiado, e novamente submetido a um ensaio cíclico, de modo a fazer-se uma análise comparativa com o ensaio prévio e assim retirar conclusões sobre a eficácia da solução de reforço aplicada.

El AUP en Nicaragua

Quizás sea conveniente recordar que en 1972 un terremoto destruyó las principales bibliotecas de Nicaragua. Durante la insurrección de 1979 fueron saqueadas o destruidas las demás. La mayoría de los profesionales huyó quedando únicamente 17 bibliotecarios en el país.La gran cruzada de Alfabetización en 1980, que se planteó como primer tarea revolucionaria, produjo un aumento en la población lectora de 400.000 personas en solo un año. Cómo atender a los usuarios antiguos y a esta nueva avalancha que llegó a los centros educativos con una videz reprimida durante cuarenta años de dictadura?

Natural Disaster and Intangible Heritage: Beyond the Horizon

When 7.8-magnitude earthquake struck Nepal in 2015, many monuments, temples and houses turned into rubbles killing more than 8,000 people and injuring above 21,000. This unfortunate and tragic natural disaster brought international attention to Nepal. But in this time of despair and pain there was a sign of hope that should be acknowledged well, the spirit of community facing the disaster. This paper is about the indigenous community of Kathmandu on how they organized an important traditional festival just four months after the disaster when most the people were still living in the makeshifts, along with the smaller aftershock continuing almost everyday. In the country like Nepal with numerous intangible heritages, which is, still living is not taken seriously by the concerned authorities and mostly been neglected. It is the indigenous community who has been carrying out those heritages, as they are inseparable aspect of the social life. With this paper it tries look at the community involvement and intangible heritage of Kathmandu Valley, which is a part of my PhD research thesis.

Brain emotional learning based control of a SDOF structural system with a MR damper

This paper describes the application of a Brain Emotional Learning (BEL) controller to improve the response of a SDOF structural system under an earthquake excitation using a magnetorheological (MR) damper. The main goal is to study the performance of a BEL based semi-active control system to generate the control signal for a MR damper. The proposed approach consists of a two controllers: a primary controller based on a BEL algorithm that determines the desired damping force from the system response and a secondary controller that modifies the input current to the MR damper to generate a reference damping force. A parametric model of the damper is used to predict the damping force based on the piston motion and also the current input. A Simulink model of the structural system is developed to analyze the effectiveness of the semi-active controller. Finally, the numerical results are presented and discussed.

Inverse identification of the bending stiffness of a braided polyethylene twine subject to large deformation: application to the identification of the mesh opening rigidity of fishing nets.

The evaluation of the mesh opening stiffness of fishing nets is an important issue in assessing the selectivity of trawls. It appeared that a larger bending rigidity of twines decreases the mesh opening and could reduce the escapement of fish. Nevertheless, netting structure is complex. A netting is made up of braided twines made of polyethylene or polyamide. These twines are tied with non-symmetrical knots. Thus, these assemblies develop contact-friction interactions. Moreover, the netting can be subject to large deformation. In this study, we investigate the responses of netting samples to different types of solicitations. Samples are loaded and unloaded with creep and relaxation stages, with different boundary conditions. Then, two models have been developed: an analytical model and a finite element model. The last one was used to assess, with an inverse identification algorithm, the bending stiffness of twines. In this paper, experimental results and a model for netting structures made up of braided twines are presented. During dry forming of a composite, for example, the matrix is not present or not active, and relative sliding can occur between constitutive fibres. So an accurate modelling of the mechanical behaviour of fibrous material is necessary. This study offers experimental data which could permit to improve current models of contact-friction interactions [4], to validate models for large deformation analysis of fibrous materials [1] on a new experimental case, then to improve the evaluation of the mesh opening stiffness of a fishing net

A cidade e o rio: origem e evolução da frente ribeirinha de Lisboa

Em Lisboa, ao longo dos séculos, o homem foi conquistando as águas do Tejo. Hoje, após os diversos aterros, a frente ribeirinha da cidade é uma consolidada faixa de terreno, rematada por muros que, contra a «ondulação» do Tejo, definem uma expandida área que acolhe uma intensa actividade portuária. Foi nesta faixa junto do rio que se desenrolou parte importante da história de Lisboa, desde as ocupações romana e muçulmana, e também muito particularmente aquando do período dos Descobrimentos, da reconstrução pombalina pós-terramoto e do surto industrial do século XIX. Alguns destes momentos históricos encontram-se reflectidos nas inúmeras plantas, cartas e mapas disponíveis neste estudo, desde a Planta da Cidade de Lisboa : 1650, de João Nunes Tinoco, até ao Plano de Melhoramentos do Porto de Lisboa, de 1946. É com base nessas plantas, mas também em cartas manuscritas, relatos de época, gravuras e fotografias antigas – documentos em grande parte inéditos –, que este trabalho de investigação propõe cartografar este território, realizando desenhos originais que possibilitam um novo olhar sobre o seu processo de crescimento e consolidação. Assim, este estudo concilia todos estes elementos, constituindo uma análise completa que se debruça sobre a evolução da frente ribeirinha de Lisboa e que permite descobrir inúmeros aspectos até aqui desconhecidos, ajudando a responder à pergunta que hoje se coloca: perante o cenário que o porto actual atravessa, como melhor poderá Lisboa recuperar a relação com o rio?; THE CITY AND THE RIVER: ORIGIN AND EVOLUTION OF LISBON'S RIVERFRONT ABSTRACT: In Lisbon, over the centuries, man was conquering the waters of the Tagus. Today, after the various landfills, the city's riverfront is a consolidated strip of land, finished by walls that, against the "ripple" of the Tagus, define an expanded area that hosts an intense port activity. It was in this band along the river that unfolded important part of the history of Lisbon, from the Roman and Muslim occupations, and also very particularly during the period of the Discoveries, the post-earthquake reconstruction, and the industrial boom of the nineteenth century. Some of these historical moments are reflected in many plans, charts and maps available in this study, since the plan designated Planta da Cidade de Lisboa : 1650, made by João Nunes Tinoco, to the plan called Plano de Melhoramentos do Porto de Lisboa, drawn in the year of 1946. Based on these plans, but also in handwritten letters, time reports, antique prints and photographs – documents that are mostly unpublished – this research work proposes map this territory, performing original drawings that provide a new look at their growth process and consolidation. Thereby, this study combines all these elements, providing a complete analysis which focuses on the evolution of the Lisbon riverfront and that allows you to discover many aspects unknown until now, helping to answer the question that now arises: according to the present scenario that the harbour is going through, how can Lisbon recover the relationship with the river?