Fluid Flow Analysis on Sheared Rock Masses using the Discrete Fracture Network Method

作     者：Larissa Kamseu 

作者单位：绍兴文理学院 

学位级别：硕士

导师姓名：Li Bo;Shi Lilian;Huang Yongliang

授予年度：2019年

学科分类：08[工学] 080104[工学-工程力学] 0815[工学-水利工程] 0801[工学-力学（可授工学、理学学位）] 

主      题：Permeability Fractured rock masses Shear Discrete Fracture Network (DFN) Coupled Hydro-mechanical Processes Normal stiffness 

摘      要：While shear flow behavior through fractured media has so far been studied at the scale of single fractures,we propose a numerical analysis on the effect of shearing deformation on the permeability and fluid flow patterns at the scale of fractured rock masses,using a twodimensional distinct element program based on a realistic discrete fracture network *** the assumption that the rock matrix is impermeable,linearly elastic and fluid flows only in fractures,we carried out several numerical experiments on three fracture network *** varying fracture densities(1.4,1.45 and 1.5),we calculated the changes in permeability of the stimulated shearing fractured rock mass under different criteria,and the influence of shear on the mechanical properties of the fracture *** included normal fracture stiffness variation,fracture densities,normal stress loading conditions,and permeability flow in both horizontal and vertical *** numerical experiments show that upon initiation of shear,the permeability increases or decreases,with contact asperities overriding each other,thereby leading to an increase in shear stress with the increasing shear displacement,which causes the change in the mechanical properties of the network and the reorientation of the fluid flow *** existence of different orientations of fractures and their connectivity in different stress states defines the possible behavior of *** change in permeability with maximum minimum flow rate of 1E-8 and 1E-9 respectively,are plotted against the shearing rate displacement of *** simulation results showed that,for flow in the horizontal direction,the shearing aperture during shearing greatly influenced the flow no matter the densities of the cracks present;and for flow in the vertical direction,the rate of shearing displacement and degree of dilation influenced the fluid *** the other hand,the varying fracture stiffness values changes in accordance to the surr