932 resultados para Geotechnical incidents
Resumo:
La Administración General del Estado, a través de la Comisión Nacional de la Energía, y en colaboración con los órganos competentes de las Comunidades Autónomas correspondientes, realiza inspecciones periódicas y aleatorias cada año, sobre las instalaciones de generación eléctrica, siguiendo los criterios de elección e indicaciones que la Secretaria General de la Energía del Ministerio de Industria, Turismo y Comercio imponga en cada caso. En este proyecto se analizan las distintas incidencias de las distintas tecnologías estudiadas, así como las consecuencias jurídicas y económicas. También se ofrecen las distintas propuestas de sanción como consecuencia de estas incidencias. El objeto del presente proyecto es el estudio de la reducción de costes al estado si el organismo competente (Comisión Nacional de Energía) liquidase a las diferentes instalaciones en función de las irregularidades detectadas como consecuencia de las inspecciones realizadas durante el plan 2011/2012, así como una estimación de dicho ahorro al extrapolar dichos resultados al total de instalaciones ABSTRACT The Central Government, through the National Energy Commission, in cooperation with the competent bodies of the Autonomous Communities concerned, realizes periodic and random inspections every year on electricity generation facilities, following the criteria of choice and indications that the General Secretary of Energy from the Ministry of Industry, Tourism and Commerce impose in each case. This project analyses the different incidences of the different technologies studied as well as the legal and economic consequences. It is also offered different proposals of sanction as a result of these incidents. The purpose of this project is to study the reduction of costs to the state if the competent agency (CNE) decided to close the different facilities depending on the irregularities as a result of inspections conducted during the plan 2011/2012 and as an estimate of the savings to extrapolate these results to all the facilities.
Resumo:
El proyecto tiene como objetivo realizar el diseño de la cimentación de Torre Reforma. Torre Reforma se ubica en Av. Paseo de la Reforma No. 483, en la esquina con Rio Elba, en la ciudad de México. Dicha ubicación geotécnicamente corresponde a lo que se conoce como la Zona de Lago. La superficie construida será de 2780 m2 y el edificio contará con una altura de 244 m y un total de 57 plantas. Por debajo del nivel de calle el edificio constará de 10 niveles de sótano destinados a aparcamiento. Partiendo de los parámetros geotécnicos del terreno, el proyecto consistirá en calcular una parte de la cimentación empleada en este edificio. Este proyecto se podrá utilizar como guía para realizar cimentaciones parecidas para otros edificios. ABSTRACT The objective of this Project is to make the design of the foundation of Torre Reforma. Torre Reforma is located in Av. Paseo de la Reforma No. 483, on the corner with Río Elba in México City. Geotechnically this location corresponds to what it is known as “la Zona del Lago” or Lake Zone. The constructed area is of 2780 m2 and the building will have a height of 244 m and a total of 57 floors. Below street level the building will include ten basement levels for parking. Based on the geotechnical parameters of the site, the project will consist in calculating a part of the foundation used in this building. This project will be able to be used as a guide for future projects of foundations of buildings in similar conditions.
Resumo:
This paper focuses on the railway rolling stock circulation problem in rapid transit networks, in which frequencies are high and distances are relatively short. Although the distances are not very large, service times are high due to the large number of intermediate stops required to allow proper passenger flow. The main complicating issue is the fact that the available capacity at depot stations is very low, and both capacity and rolling stock are shared between different train lines. This forces the introduction of empty train movements and rotation maneuvers, to ensure sufficient station capacity and rolling stock availability. However, these shunting operations may sometimes be difficult to perform and can easily malfunction, causing localized incidents that could propagate throughout the entire network due to cascading effects. This type of operation will be penalized with the goal of selectively avoiding them and ameliorating their high malfunction probabilities. Critic trains, defined as train services that come through stations that have a large number of passengers arriving at the platform during rush hours, are also introduced. We illustrate our model using computational experiments drawn from RENFE (the main Spanish operator of suburban passenger trains) in Madrid, Spain. The results of the model, achieved in approximately 1 min, have been received positively by RENFE planners
Resumo:
The aim of this paper is to propose an integrated planning model to adequate the offered capacity and system frequencies to attend the increased passenger demand and traffic congestion around urban and suburban areas. The railway capacity is studied in line planning, however, these planned frequencies were obtained without accounting for rolling stock flows through the rapid transit network. In order to provide the problem more freedom to decide rolling stock flows and therefore better adjusting these flows to passenger demand, a new integrated model is proposed, where frequencies are readjusted. Then, the railway timetable and rolling stock assignment are also calculated, where shunting operations are taken into account. These operations may sometimes malfunction, causing localized incidents that could propagate throughout the entire network due to cascading effects. This type of operations will be penalized with the goal of selectively avoiding them and ameliorating their high malfunction probabilities. Swapping operations will also be ensured using homogeneous rolling stock material and ensuring parkings in strategic stations. We illustrate our model using computational experiments drawn from RENFE (the main Spanish operator of suburban passenger trains) in Madrid, Spain. The results show that through this integrated approach a greater robustness degree can be obtained
Resumo:
Ya en el informe acerca del estado de la tecnología en la excavación profunda y en la construcción de túneles en terreno duro presentado en la 7ª Conferencia en Mecánica de Suelos e Ingeniería de la Cimentación, Peck (1969) introdujo los tres temas a ser tenidos en cuenta para el diseño de túneles en terrenos blandos: o Estabilidad de la cavidad durante la construcción, con particular atención a la estabilidad del frente del túnel; o Evaluación de los movimientos del terreno inducidos por la construcción del túnel y de la incidencia de los trabajos subterráneos a poca profundidad sobre los asentamientos en superficie; o Diseño del sistema de sostenimiento del túnel a instalar para asegurar la estabilidad de la estructura a corto y largo plazo. Esta Tesis se centra en los problemas señalados en el segundo de los puntos, analizando distintas soluciones habitualmente proyectadas para reducir los movimientos inducidos por la excavación de los túneles. El objeto de la Tesis es el análisis de la influencia de distintos diseños de paraguas de micropilotes, pantalla de micropilotes, paraguas de jet grouting y pantallas de jet grouting en los asientos en superficie durante la ejecución de túneles ejecutados a poca profundidad, con objeto de buscar el diseño que optimice los medios empleados para una determinada reducción de asientos. Para ello se establecen unas premisas para los proyectistas con objeto de conocer a priori cuales son los tratamientos más eficientes (de los propuestos en la Tesis) para la reducción de asientos en superficie cuando se ha de proyectar un túnel, de tal manera que pueda tener datos cualitativos y algunos cuantitativos sobre los diseños más óptimos, utilizando para ello un programa de elementos finitos de última generación que permite realizara la simulación tensodeformación del terreno mediante el modelo de suelo con endurecimiento (Hardening Soil Small model), que es una variante elastoplástica del modelo hiperbólico, similar al Hardening Soil Model. Además, este modelo incorpora una relación entre deformación y el modulo de rigidez, simulando el diferente comportamiento del suelo para pequeñas deformaciones (por ejemplo vibraciones con deformaciones por debajo de 10-5 y grandes deformaciones (deformaciones > 10-3). Para la realización de la Tesis se han elegido cinco secciones de túnel, dos correspondiente a secciones tipo de túnel ejecutado con tuneladora y tres secciones ejecutados mediante convencionales (dos correspondientes a secciones que han utilizado el método Belga y una que ha utilizado el NATM). Para conseguir los objetivos marcados, primeramente se ha analizado mediante una correlación entre modelos tridimensionales y bidimensionales el valor de relajación usado en estos últimos, y ver su variación al cambio de parámetros como la sección del túnel, la cobertera, el procedimiento constructivo, longitud de pase (métodos convencionales) o presión del frente (tuneladora) y las características geotécnicas de los materiales donde se ejecuta el túnel. Posteriormente se ha analizado que diseño de pantalla de protección tiene mejor eficacia respecto a la reducción de asientos, variando distintos parámetros de las características de la misma, como son el empotramiento, el tipo de micropilotes o pilote, la influencia del arriostramiento de las pantallas de protección en cabeza, la inclinación de la pantalla, la separación de la pantalla al eje del túnel y la disposición en doble fila de la pantalla de pantalla proyectada. Para finalizar el estudio de la efectividad de pantalla de protección para la reducción de asiento, se estudiará la influencia de la sobrecarga cercanas (simulación de edificios) tiene en la efectividad de la pantalla proyectada (desde el punto de vista de reducción de movimientos en superficie). Con objeto de poder comparar la efectividad de la pantalla de micropilotes respecto a la ejecución de un paraguas de micropilotes se ha analizado distintos diseños de paraguas, comparando el movimiento obtenido con el obtenido para el caso de pantalla de micropilotes, comparando ambos resultados con los medidos en obras ya ejecutadas. En otro apartado se ha realizado una comparación entre tratamientos similar, comparándolos en este caso con un paraguas de jet grouting y pantallas de jet grouting. Los resultados obtenidos se han con valores de asientos medidos en distintas obras ya ejecutadas y cuyas secciones se corresponden a los empleados en los modelos numéricos. Since the report on the state of technology in deep excavation and tunnelling in hard ground presented at the 7th Conference on Soil Mechanics and Foundation Engineering, Peck (1969) introduced the three issues to be taken into account for the design of tunnels in soft ground: o Cavity Stability during construction, with particular attention to the stability of the tunnel face; o Evaluation of ground movements induced by tunnelling and the effect of shallow underground workings on surface settlement; o Design of the tunnel support system to be installed to ensure short and long term stability of the structure. This thesis focuses on the issues identified in the second point, usually analysing different solutions designed to reduce the movements induced by tunnelling. The aim of the thesis is to analyse the influence of different micropile forepole umbrellas, micropile walls, jet grouting umbrellas and jet grouting wall designs on surface settlements during near surface tunnelling in order to use the most optimal technique to achieve a determined reduction in settlement. This will establish some criteria for designers to know a priori which methods are most effective (of those proposed in the thesis) to reduce surface settlements in tunnel design, so that it is possible to have qualitative and some quantitative data on the optimal designs, using the latest finite element modelling software that allows simulation of the ground’s infinitesimal strain behaviour using the Hardening Soil Small Model, which is a variation on the elasto-plastic hyperbolic model, similar to Hardening Soil model. In addition, this model incorporates a relationship between strain and the rigidity modulus, simulating different soil behaviour for small deformations (eg deformation vibrations below 10-5 and large deformations (deformations > 10-3). For the purpose of this thesis five tunnel sections have been chosen, two sections corresponding to TBM tunnels and three sections undertaken by conventional means (two sections corresponding to the Belgian method and one corresponding to the NATM). To achieve the objectives outlined, a correlation analysis of the relaxation values used in the 2D and 3D models was undertaken to verify them against parameters such as the tunnel cross-section, the depth of the tunnel, the construction method, the length of step (conventional method) or face pressure (TBM) and the geotechnical characteristics of the ground where the tunnel is constructed. Following this, the diaphragm wall design with the greatest efficiency regarding settlement reduction was analysed, varying parameters such as the toe depth, type of micropiles or piles, the influence of bracing of the head protection diaphragm walls, the inclination of the diaphragm wall, the separation between the diaphragm wall and the tunnel axis and the double diaphragm wall design arrangement. In order to complete the study into the effectiveness of protective diaphragm walls ofn the reduction of settlements, the influence of nearby imposed loads (simulating buildings) on the effectiveness of the designed diaphragm walls (from the point of view of reducing surface movements) will be studied. In order to compare the effectiveness of micropile diaphragm walls regarding the installation of micropile forepole umbrellas, different designs of these forepole umbrellas have been analysed comparing the movement obtained with that obtained for micropiled diaphragm walls, comparing both results with those measured from similar completed projects. In another section, a comparison between similar treatments has been completed, comparing the treatments with a forepole umbrella by jet grouting and jet grouting walls. The results obtained compared with settlement values measured in various projects already completed and whose sections correspond to those used in the numerical models.
Resumo:
Three broken steel bars from a sewed crack in a dam are reported. The inspection of the fracture surfaces of the prestressed bars suggests that fractures were triggered by small cracks and by the inherent brittleness of the bars, as fracture toughness was about 40 MPa m1/2. The analysis of the failures shows that the usual design requirements for prestressing bars fail to warn against brittle failures if some damage exists. Some recommendations, based on the concept of damage tolerance, are suggested to avoid similar unfortunate incidents.
Resumo:
The aim of this study was to examine the effect of positioning on the correctness of decision making of top-class referees and assistant referees during international games. Match analyses were carried out during the Fe´de´ration Internationale de Football Association (FIFA) Confederations Cup 2009 and 380 foul play incidents and 165 offside situations were examined. The error percentage for the referees when indicating the incidents averaged 14%. The lowest error percentage occurred in the central area of the field, where the collaboration of the assistant referee is limited, and was achieved when indicating the incidents from a distance of 11–15 m, whereas this percentage peaked (23%) in the last 15-min match period. The error rate for the assistant referees was 13%. Distance of the assistant referee to the offside line did not have an impact on the quality of the offside decision. The risk of making incorrect decisions was reduced when the assistant referees viewed the offside situations from an angle between 46 and 608. Incorrect offside decisions occurred twice as often in the second as in the first half of the games. Perceptual-cognitive training sessions specific to the requirements of the game should be implemented in the weekly schedule of football officials to reduce the overall error rate.
Resumo:
El objetivo de este proyecto es realizar el estudio geológico-geotécnico para la construcción de un muelle pesquero. Para caracterizar el terreno se ha realizado una campaña geotécnica compuesta por 4 sondeos y diversos ensayos “in situ”; así mismo se obtuvieron muestras inalteradas, con las que se realizaron ensayos de laboratorio. Entre los trabajos desarrollados se han realizado cortes geológicos-geotécnicos; cuyos resultados han servido para caracterizar los niveles geotécnicos. Posteriormente para definir las soluciones y procesar los datos se utilizó el software GeoSlope, con el que se estudió dos distintas alternativas posibles para realizar la cimentación del muelle: muelle vertical sin columnas de grava y muelle vertical con columnas de grava. Finalmente, los resultados obtenidos demostraron que la alternativa óptima sería una pantalla de columnas de grava considerando diversos factores técnicos, estructurales y económicos. ABSTRACT The objective of this project is to develop a geological and geotechnical study for the construction of a fishing quay. To characterize the field it has been done a geotechnical campaign with 4 drills and various "in situ" assays, likewise undisturbed samples were obtained, on which laboratory tests were performed. Among all the performed works, geological-geotechnical profiles were made, whose results have been used to characterize the geotechnical levels. Subsequently to define solutions and to process all the data, GeoSlope software was used, with which two different options for the quay foundation were studied: vertical quay without gravel columns and vertical quay with gravel columns. Finally, the results showed that the best alternative would be a gravel screen columns considering various technical, structural and economic factors.
Resumo:
Este proyecto pretende ofrecer una visión general de una de las tecnologías más actuales de recuperación de gas en formaciones no convencionales: fracturación hidráulica o “fracking”. El proyecto está motivado por la necesidad de responder a diferentes cuestiones sobre los efectos ambientales, sociales y en la salud humana derivados de la utilización de esa tecnología. Ofrece, además, una descripción del proceso y utilización de la tecnología haciendo especial mención de los riesgos inherentes de su uso, aunque también se intenta establecer una vía de aceptación para su desarrollo cuyo fin último, a parte de los beneficios económicos de quienes la usan, es el de posibilitar la transición hacia el uso de unos recursos (energías fósiles de extracción no convencional) que requieren de dichas técnicas para mantener, a lo largo del tiempo, el suministro de una energía que se supone más respetuosa con el medio ambiente: el gas natural. En primer lugar se expone, a modo introductorio, la necesidad de utilización de nuevas técnicas de estimulación de pozos y su utilización para satisfacer las necesidades energéticas mundiales en los próximos años. A continuación se hace una revisión del marco regulatorio aplicable al gas no convencional. Seguidamente, se hace una descripción de los recursos y fuentes no convencionales de gas y la descripción del proceso de fracturación hidráulica. Se analizan los incidentes relacionados con su desarrollo y las posibilidades y mecanismos que pueden adoptarse para reducirlos. Finalmente, se proponen vías alternativas basadas en las mejores técnicas aplicables al uso de la tecnología, cuya finalidad sea la mayor consideración ambiental posible y el menor riesgo posible en la salud de las personas. ABSTRACT This project aims to provide an overview of the latest technologies in gas recovery unconventional formations: hydraulic fracturing or "fracking". The project is motivated by the need to respond to various questions on the environmental, social and human health arising from the use of this technology. It also offers a description of the process and use of technology with special mention of the inherent risks of their use, but also tries to establish a path of acceptance for development whose ultimate goal, apart from the economic benefits of those who use is of enabling the transition to the use of certain resources (fossil energy extraction unconventional) which require such techniques to maintain, over time, of an energy supply which is more environmentally friendly: natural gas. First discussed the need to use new well stimulation techniques and their use to meet the world's energy needs in the coming years. Below is a review of the regulatory framework applicable to unconventional gas. Next, there is a description of resources and unconventional sources of gas, and the description of the process of hydraulic fracturing. We analyze the incidents related to its development and the possibilities and mechanisms that can be taken to reduce them. Finally, we suggest alternative routes based on the best techniques applicable to the use of technology, aiming at the highest possible environmental consideration and the least possible risk to the health of people.