scholarly journals Modelling of Groundwater Flow in Fractured Rocks

2015 ◽  
Vol 25 ◽  
pp. 142-149 ◽  
Author(s):  
Gy. Karay ◽  
G. Hajnal
Keyword(s):  
Groundwater Flow ◽  
Fractured Rocks

scholarly journals Flexible parallel implicit modelling of coupled thermal–hydraulic–mechanical processes in fractured rocks

Solid Earth ◽  
2017 ◽  
Vol 8 (5) ◽  
pp. 921-941 ◽  
Author(s):  
Mauro Cacace ◽  
Antoine B. Jacquey
Keyword(s):  
Groundwater Flow ◽  
Fractured Rocks ◽  
Object Oriented ◽  
Coupled System ◽  
Weak Sense ◽  
Rock Properties ◽  
Solid Matrix ◽  
Scaling Parameters ◽  
Active Processes ◽  
Element Technique

Abstract. Theory and numerical implementation describing groundwater flow and the transport of heat and solute mass in fully saturated fractured rocks with elasto-plastic mechanical feedbacks are developed. In our formulation, fractures are considered as being of lower dimension than the hosting deformable porous rock and we consider their hydraulic and mechanical apertures as scaling parameters to ensure continuous exchange of fluid mass and energy within the fracture–solid matrix system. The coupled system of equations is implemented in a new simulator code that makes use of a Galerkin finite-element technique. The code builds on a flexible, object-oriented numerical framework (MOOSE, Multiphysics Object Oriented Simulation Environment) which provides an extensive scalable parallel and implicit coupling to solve for the multiphysics problem. The governing equations of groundwater flow, heat and mass transport, and rock deformation are solved in a weak sense (either by classical Newton–Raphson or by free Jacobian inexact Newton–Krylow schemes) on an underlying unstructured mesh. Nonlinear feedbacks among the active processes are enforced by considering evolving fluid and rock properties depending on the thermo-hydro-mechanical state of the system and the local structure, i.e. degree of connectivity, of the fracture system. A suite of applications is presented to illustrate the flexibility and capability of the new simulator to address problems of increasing complexity and occurring at different spatial (from centimetres to tens of kilometres) and temporal scales (from minutes to hundreds of years).

scholarly journals Reviews of lnvestigation and Analysis methods for Groundwater Flow in Fractured Rocks

2002 ◽  
Vol 44 (2) ◽  
pp. 81-103 ◽  
Author(s):  
Masahito YOSHIMURA ◽  
Masayuki IMAIZUMI ◽  
Yasuo SAKURA ◽  
Changyuan TANG
Keyword(s):  
Groundwater Flow ◽  
Fractured Rocks ◽  
Analysis Methods

scholarly journals Flexible parallel implicit modelling of coupled Thermal-Hydraulic-Mechanical processes in fractured rocks

2017 ◽  
Author(s):  
Mauro Cacace ◽  
Antoine B. Jacquey
Keyword(s):  
Groundwater Flow ◽  
Fractured Rocks ◽  
Object Oriented ◽  
Coupled System ◽  
Weak Sense ◽  
Rock Properties ◽  
Solid Matrix ◽  
Scaling Parameters ◽  
Active Processes ◽  
Element Technique

Abstract. Theory and numerical implementation describing groundwater flow and the transport of heat and solute mass in fully saturated fractured rocks with elasto-plastic mechanical feedbacks are developed. In our formulation, fractures are considered as being of lower dimension than the hosting deformable porous rock and we consider their hydraulic and mechanical apertures as scaling parameters to ensure continuous exchange of fluid mass and energy within the fracture-solid matrix system. The coupled system of equations is implemented into a new simulator code that makes use of a Galerkin Finite Element technique. The code builds on a flexible, object oriented numerical framework (MOOSE, Multiphysics Object Oriented Simulation Environment) which provides an extensive scalable parallel, implicit coupling to solve for the multiphysics problem. The governing equations of groundwater flow, heat and mass transport and rock deformation are solved in a weak sense (either by classical Newton- Raphson or by Free Jacobian Inexact Newton Krylow schemes) on an underlying unstructured mesh. Non-linear feedbacks among the active processes are enforced by considering evolving fluid and rock properties depending on the thermo-hydro-mechanical state for the system and the local structure, i.e. degree of connectivity, of the fracture system. A suite of applications is presented to illustrate the flexibility and capability of the new simulator to address problems of increasing complexity and occurring at different spatial (from centimeters to tens of kilometers) and temporal scales (from minutes to hundreds of years).

scholarly journals Short review of some methods for groundwater flow assessment in fractured rock masses

2018 ◽  
Vol 7 (3) ◽  
pp. 7-17
Author(s):  
Paola Gattinoni ◽  
Laura Scesi
Keyword(s):  
Porous Media ◽  
Groundwater Flow ◽  
Fractured Rocks ◽  
Fractured Rock ◽  
Short Review ◽  
Point Of View ◽  
Rock Masses ◽  
Water Research ◽  
Engineering Problems ◽  
Fractured Rock Masses

Water flow in fractured rock masses is a key issue in many typical environmental and engineering problems. Still, aquifers in fractured rocks are devoted much less attention than those in porous media, as they are considered less important from the point of view of water research, but also because rock masses are a very complex medium (heterogeneous, anisotropic and discontinuous), and therefore its modelling is a quite hard task. This paper proposes a review on recent researches concerning groundwater flow in fractured rock masses. In particular, the main issues involved in the reconstruction of the hydrogeological conceptual model are addressed, mainly for fissured and partly for karsts rocks, and the following choice of the most suitable modeling approach is critically discussed, through applicative examples.

Numerical simulation of steady state groundwater flow field in discretely fractured rocks using the Green element method with the concept of multiple interacting normal flux

2020 ◽  
Author(s):  
Tai-Sheng Liou
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Groundwater Flow ◽  
Fractured Rocks ◽  
Triangular Element ◽  
System Of Equations ◽  
Boundary Segment ◽  
Grid Block ◽  
Groundwater Flow Field ◽  
Element Method

<p>Numerical simulation is an effective tool for estimating the groundwater flow field in discretely fractured rocks (DFR). Unlike most numerical simulation methods that require the discretization of the model domain, boundary element method (BEM) is renowned of waiving the spatial discretization task but focusing on solving the integral form of the governing groundwater flow equation. However, for groundwater flow simulation in DFR, the solution obtained by BEM tends to have large error in the vicinity of fracture intersection. Therefore, a new numerical scheme, the green element method (GEM) is adopted in this study. GEM is built on the same mathematical background as BEM but turns the domain discretization back on as a necessary task. Using the second Green’s identity, GEM produces a general equation that applies to each grid block by integrating the governing equation. By making use of the singular characteristic of the Green’s function, GEM transforms the integral equation into a discretized system of equations with nodal head or nodal head gradient as unknowns. The cost of discretizing the model domain is compensated by the convenience of handling the heterogeneity of the medium. Conventional GEM manages the normal flux across a boundary segment by differentiating head values from 2 nodes in an individual grid block. This approximation overlooks the mechanism of normal flux as the exchange of fluid mass between grid blocks. To take this mechanism into consideration, a modified model of normal flux is proposed if the fracture plane is discretized into triangular elements. This model expresses the normal flux across a grid boundary segment in terms of the difference of head values in two grid blocks that are connected to this segment. For convenience, the head value at the centroid of a triangular element is used to calculate the normal flux. In other words, the unknowns of a triangular element are three nodal heads plus one centroidal head. Thus, the modified normal flux will be able to consider the interaction of all grid blocks that are connected to a target grid block. More importantly, the resulting global coefficient matrix is a square one and the system of equations is closed. The solution obtained from the closed system of equations will be exact but not a least-square approximated one. This modified GEM will be applied to simulate the steady state groundwater flow field in discretely fractured rocks.</p>

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