COLLECTIONS

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• Análisis numérico del proceso de filtración en presas de escollera

  C. Tapia, E. Oñate, A. LARESE

  (2009). Research Report, IT-591

  
  

  Abstract

  Las presas de materiales sueltos funcionan como presas de gravedad, el peso propio de los materiales que la componen aportan la resistencia necesaria para soportar el empuje horizontal y la flexión que producen las aguas en el trasdós. El inconveniente principal de éstas presas está en el sobrevertido. Si se produce una avenida y el agua vierte sobre la presa, ésta se comporta de manera inestable y puede colapsarse y desmoronarse. Se sabe que este fenómeno del sobrevertido es una de las principales razones por las que colapsan este tipo de presas, pero se trata de un fenómeno poco conocido y poco desarrollado. Por ello existe un interés cada vez mayor en el estudio del comportamiento de las presas de materiales sueltos cuando se lleva a cabo el llenado, y el sobrevertido de agua sobre el talud aguas abajo. Este estudio está limitado por la ausencia de un método de cálculo, por lo que es esencial llegar a constituir un método numérico que modelice el comportamiento físico de estos procesos en dichas presas.

  Abstract
  Las presas de materiales sueltos funcionan como presas de gravedad, el peso propio de los materiales que la componen aportan la resistencia necesaria para soportar el empuje [...]

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• A mixed Lagrangian and Eulerian FSI approach for simulation of overtopping on embankment dams

  A. LARESE, R. Rossi

  (2009). "III International Conference on Computational Methods for Coupled Problems in Science and Engineering". Ischia: CIMNE (Centro Internacional de Métodos Numéricos en Ingeniería), p. 1-4.

  
  

  Abstract

  The present work is concerned with some recent advances in FSI simulations with particular emphasis on the simulation of rockfill dams during extreme phenomena. The final objective is the study of the consequences of an overtopping on the stability of such structure and its possible failure mode. A mixed Lagrangian and Eulerian approach is used. The fluid behavior is described using a modified form of the Navier Stokes equations in order to consider the effect of a variable porosity. A non linear Darcy law is included in the momentum equation. A level set function is chosen to follow the movement of the free surface inside and outside the porous medium. The structure is described using a purely lagrangian PFEM formulation. The specific features of PFEM make it appropriate to treat the rockfill material and its large deformations and shape changes. A projection technique allows to perform the data transfer between the fluid and the structure non matching meshes

  Abstract
  The present work is concerned with some recent advances in FSI simulations with particular emphasis on the simulation of rockfill dams during extreme phenomena. The final [...]

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• Particle finite element method and level set method for the simulation of the failure of rockfill dams due to overtopping phenomena

  A. LARESE, R. Rossi, S. Idelsohn

  (2010). 8th. World Congress on Computational Mechanics (WCCM8) 5th European Congress on Computational Methods in Applied Sciences and Engineering (ECCOMAS 2008)

  
  

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• On the Validation of The Particle Finite Element Method (PFEM) for complex engineering fluid flow problems

  A. LARESE, R. Rossi, S. Idelsohn

  (2010). European Conference on Computational Fluid Dynamics ECCOMAS CFD 2006 P. Wesseling, E. Oñate and J. Périaux (Eds)

  
  

  Abstract

  Several comparisons between experiments and computational models are presented in the following pages. The objective is to verify the ability of Particle Finite Elements Methods (PFEM) to reproduce hydraulic phenomena involving large deformation of the fluid domain.

  Abstract
  Several comparisons between experiments and computational models are presented in the following pages. The objective is to verify the ability of Particle Finite Elements Methods [...]

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• Metodología de análisis del comportamiento de presas de escollera frente a un sobrevertido

  A. LARESE, R. Rossi, M. Toledo

  (2010). Actas de IX Jornadas Españolas de Presas

  
  

  Abstract

  Con el objetivo de llegar a un mejor conocimiento del principio del proceso de rotura de las presas de material suelto y obtener una herramienta que permita un análisis más riguroso de este fenómeno, se está desarrollando el proyecto XPRES financiado por el Ministerio de Educación y Ciencia [XPRES 2007-2010]. El proyecto consta de una parte experimental, llevada a cabo por CEDEX y UPM conjuntamente, y de una parte numérica, desarrollada en el Centro Internacional de Métodos Numéricos en Ingeniería (CIMNE). En el presente trabajo se quiere presentar lo que CIMNE está realizando para crear una herramienta de cálculo para el análisis del comportamiento de una presa de escollera durante un sobrevertido, que, por su incidencia en la seguridad de la presa y su entorno, merece un tratamiento más preciso. La nueva metodología permite analizar con detalle el estado de tensión y deformación de la presa y su posible rotura parcial, o catastrófica, bajo la acción del flujo de agua y combina métodos de elementos finitos avanzados con métodos de partículas.

  Abstract
  Con el objetivo de llegar a un mejor conocimiento del principio del proceso de rotura de las presas de material suelto y obtener una herramienta que permita un análisis [...]

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• Physical and numerical modelization of the behaviour of rockfill dams during overtopping scenarios

  A. Larese, R. Rossi, M. Toledo

  "Dam maintenance and rehabilitation II: proceedings of the 2nd international congress on dam maintenance and rehabilitation, Zaragoza, Spain, 23-25 November 2010". Boca Raton, FL: CRC Press. Taylor & Francis Group, p. 479-487

  
  

  Abstract

  In recent years the technology on embankments dams has developed sensibly due to the advances in soil mechanic, and in all related sciences. Nevertheless their vulnerability to overtopping is still an open theme of discussion. Such an extreme phenomenon can lead to catastrophic consequences with loss of stability and failure of the entire structure. In spite of that, the consequences of an overtopping are still difficult to analyze and to prevent optimally. The possibility to define a numerical instrument to provide support for analyzing the failure of a dam is an important step ahead for organizing the intervention measures and for optimizing the economic plan. This is the principal reason why the Spanish ministry of Science and Innovation is funding the XPRES project, between the Polytechnic University of Madrid (UPM), the Centre for Hydrographical Studies of CEDEX and the International Centre for Numerical Methods in Engineering (CIMNE). The characterization of the failure process is dealt with by combining new numerical models, developed by CIMNE, with experimental tests on physical models of different sizes and scales carried out by UPM and CEDEX. In the present paper the work carried out by CIMNE is presented. The numerical model is based on combination of Lagrangian Particle Finite Element Method (PFEM) and Eulerian level set techniques in order to optimize the coupling between the dynamic effect of water inside and outside the dam, with the structural deformation and collapse induced on the down stream shoulder. The breaching formation and the consequent beginning of the failure are analyzed with particular interest. The specific features of the adopted method make it appropriate to treat the rockfill material and its large deformations and shape changes. A variable viscosity law and an energetic erosion criterion are used to take into account mass sliding and erosion acting in combined or alternative way

  Abstract
  In recent years the technology on embankments dams has developed sensibly due to the advances in soil mechanic, and in all related sciences. Nevertheless their vulnerability [...]

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• Estudios sobre el comportamiento de presas de escollera ante vertidos por coronación

  C. Lechuga, A. Lara, M. Berga, P. Viña, M. Toledo, R. Morán Moya, H. Campos, J. García-Palacios, A. Larese

  (2010). Actas de IX Jornadas Españolas de Presas

  
  

  Abstract

  Como consecuencia del desarrollo de un Proyecto de Investigación, el CEDEX, la Universidad Politécnica de Madrid y el CIMNE han trabajado conjuntamente en el desarrollo de un método para el estudio del proceso de rotura de presas de escollera por sobrevertido combinando técnicas de elementos finitos y partículas. Para ello se han realizado y analizado 80 ensayos en modelo físico en las instalaciones del CEDEX y UPM, utilizando seis tamaños de material, cuatro taludes distintos (1,5H:1V; 2,2H:1V; 3,0H:1V y 3,5H:1V) y tres opciones de impermeabilización (sin pantalla, núcleo interno y pantalla externa). Estos ensayos están permitiendo conocer mejor el fenómeno y calibrar el modelo matemático. El modelo matemático basa su desarrollo en el acoplamiento de dos fenómenos: la filtración del agua en un medio granular (simulada mediante una malla euleriana) y la erosión del propio material granular (simulada mediante una malla lagrangiana). Durante 2010 se prevé finalizar la construcción, en el CEDEX, de un canal de grandes dimensiones que permitirá ensayar presas de hasta 4 m de altura en condiciones de laboratorio, que servirán como prototipo para el análisis del efecto de escala. Este prototipo aumentará considerablemente la fiabilidad de las conclusiones obtenidas.

  Abstract
  Como consecuencia del desarrollo de un Proyecto de Investigación, el CEDEX, la Universidad Politécnica de Madrid y el CIMNE han trabajado conjuntamente en el [...]

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• PFEM application in fluid structure interaction problems

  M. Celigueta, A. LARESE, S. Latorre

  4th CONFERENCE ON ADVANTAGES AND APPLICATIONS OF GID. The Personal Pre and Post Processor

  
  

  Abstract

  In the current paper the Particle Finite Element Method (PFEM), an inno-vative numerical method for solving a wide spectrum of problems involving the interaction of fluid and structures, is briefly presented. Many examples of the use of the PFEM with GiD support are shown. GiD framework provides a useful pre and post processor for the specific features of the method. Its advantages and shortcomings are pointed out in the present work

  Abstract
  In the current paper the Particle Finite Element Method (PFEM), an inno-vative numerical method for solving a wide spectrum of problems involving the interaction of fluid [...]

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• Analysis of stability of earth dams in overtopping scenarios with the particle finite element method

  A. LARESE, R. Rossi

  (2009). International Conference on Particle-Based Methods Particles, E. Oñate and D.R.J. Owen (Eds), Barcelona

  
  

  Abstract

  The aim of this work is to study the consequences of an overtopping on the stability of earth dams and its possible failure mode. Rehabilitation and safety analysis of existing dams is nowadays an open field of research. The possibility to define a numerical instrument to provide support for analyzing the failure of a dam is a big step ahead for organizing the intervention measures and for optimizing the economic plan. In fact many existing dams have now to be modified due to the revision of previous design criteria in order to increase their safety. The objective of our work is to develop and validate a new computational method of general applicability that allows treating the above problems. The method will combine advanced finite element and particle techniques. Fluid-structure interaction effects and non-linear geometrical and mechanical effects in the dam material are considered. A mixed Lagrangian and Eulerian approach is used. The fluid behavior is described using a modified form of the Navier Stokes equations in order to consider the effect of a variable porosity. A non linear Darcy law is included in the momentum equation. A level set function is chosen to follow the movement of the free surface inside and outside the porous medium. The structure is described using a purely lagrangian PFEM formulation [1] and [2]. The specific features of PFEM make it appropriate to treat the rockfill material and its large deformations and shape changes. A projection technique allows to perform the data transfer between the fluid and the structure non matching meshes. Peer Reviewed Postprint (published version)

  Abstract
  The aim of this work is to study the consequences of an overtopping on the stability of earth dams and its possible failure mode. Rehabilitation and safety analysis of existing [...]

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• Coupling eulerian and lagrangian models to simulate seepage and evolution of failure in prototype rockfill dams

  A. LARESE, R. Rossi

  (2011). ICOLD Benchmark Workshop on Numerical Analysis of Dams. "XI ICOLD Benchmark Workshop on Numerical Analysis of Dams". València: 2011, p. 1-20.

  
  

  Abstract

  This work presents a model which allows considering the interaction between rockfill dams and the water. The fluid behaviour is analyzed on an Eulerian fixed mesh. A level set technique is employed to tack the evolution of the free surface. An edge based approach is used to solve efficiently the modified form of the Navier‐Stokes equations. The dam response is evaluated on a Lagrangian moving mesh using PFEM. A visco‐rigid constitutive model is used to describe the structural behaviour and collapse of rockfill under fluid dynamic forces. Mohr‐Coulomb is the failure criteria adopted in the calculation. Finally a nodal projection algorithm allows the transferring of information through non matching meshes.

  Abstract
  This work presents a model which allows considering the interaction between rockfill dams and the water. The fluid behaviour is analyzed on an Eulerian fixed mesh. A level [...]

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