Un método numérico para la obtención de relaciones constitutivas en rocas fracturadas
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Universidad Nacional de Rosario. Facultad de Ciencias Exactas, Ingeniería y Agrimensura. Centro Universitario Rosario de Investigaciones Hidroambientales.
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En este estudio se determinan las relaciones constitutivas para rocas fracturadas no saturadas mediante un procedimiento numérico que imita las técnicas de medición utilizadas en laboratorio. En forma computacional se generan muestras tridimensionales de roca con fracturas verticales y horizontales aleatorias. Cada fractura es conceptualizada como una placa tridimensional cuyas propiedades hidráulicas son descritas por el modelo de van Genuchten. El procedimiento se basa en la solución numérica de la ecuación de flujo no saturado estacionario en una malla regular de un millón de elementos utilizando un método híbrido mixto de elementos finitos. Los valores de saturación y conductividad hidráulica relativa se calculan numéricamente a partir de los resultados de la simulación para distintos valores de altura de presión. Las relaciones simuladas son ajustadas utilizando dos expresiones analíticas recientemente propuestas para rocas fracturadas no saturadas. Ejemplos numéricos muestran que ambos modelos pueden ajustar razonablemente las relaciones de saturación simuladas.
In this study constitutive relations for unsaturated fractured rocks using a numerical procedure that mimics the laboratory technique of measurement are determined. Three-dimensional rock samples with random vertical and horizontal fractures are computationally constructed. Each fracture is conceptualized as a three-dimensional plate whose hydraulic properties are described by the van Genuchten model. The procedure is based on the numerical solution of the steady-state unsaturated flow equation in a three-dimensional cubic domain, on a regular mesh of one million elements, using a hybridized mixed finite element method. The saturation and hydraulic conductivity values are numerically computed from the simulation results, for seve-ral values of pressure head. The simulated relations are fitted using two recently proposed analytical expre-ssions for unsaturated fractured rocks. Numerical examples show that both models can match reasonably the simulated saturation relations.
In this study constitutive relations for unsaturated fractured rocks using a numerical procedure that mimics the laboratory technique of measurement are determined. Three-dimensional rock samples with random vertical and horizontal fractures are computationally constructed. Each fracture is conceptualized as a three-dimensional plate whose hydraulic properties are described by the van Genuchten model. The procedure is based on the numerical solution of the steady-state unsaturated flow equation in a three-dimensional cubic domain, on a regular mesh of one million elements, using a hybridized mixed finite element method. The saturation and hydraulic conductivity values are numerically computed from the simulation results, for seve-ral values of pressure head. The simulated relations are fitted using two recently proposed analytical expre-ssions for unsaturated fractured rocks. Numerical examples show that both models can match reasonably the simulated saturation relations.
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Except where otherwise noted, this item's license is described as Atribución-NoComercial-CompartirIgual 2.5 Argentina (CC BY-NC-SA 2.5 AR)