COUPLING DISTINCT AND CONTINUOUS MEDIUM MODEL FOR FLOW ANALYSIS IN A FRACTURED ROCK MASS AND ITS APPLICATION

Fractures in a rock mass can be divided into dominant fracture system and network fracture system. An approach for the analysis of three dimensional ground water flow in a fractured rock mass is presented, in which flow in the dominant fracture system is described by a distinct medium model while flow in the network fracture system plus rock matrices (if considered) is described by a continuous medium model, and the two models are coupled by hydraulic head and flux. The coupling model facilitates to calculate one-by-one the fluid flow in the dominant fractures which are functioned as the major water transmission conduits, and it avoids unnecessary calculating fluid flow in individual network fractures which are numerous in number. In this way, the method can be applied to a large-sized calculation domain. In addition, a method of using network geometry data to calculate its equivalent porous permeability is presented in the paper, and the model implementation of water source and sink such as the pumping

COUPLING DISTINCT AND CONTINUOUS MEDIUM MODEL FOR FLOW ANALYSIS IN A FRACTURED ROCK MASS AND ITS APPLICATION

Fractures in a rock mass can be divided into dominant fracture system and network fracture system. An approach for the analysis of three dimensional ground water flow in a fractured rock mass is presented, in which flow in the dominant fracture system is described by a distinct medium model while flow in the network fracture system plus rock matrices (if considered) is described by a continuous medium model, and the two models are coupled by hydraulic head and flux. The coupling model facilitates to calculate one-by-one the fluid flow in the dominant fractures which are functioned as the major water transmission conduits, and it avoids unnecessary calculating fluid flow in individual network fractures which are numerous in number. In this way, the method can be applied to a large-sized calculation domain. In addition, a method of using network geometry data to calculate its equivalent porous permeability is presented in the paper, and the model imlementation of water source and sink such as the pumping wells is also discussed. Results of a theoretical test calculation and a case study show that the coupled approach can effectively analyze ground water flow in a fractured rock mass.