Chapter 7 - Instability and Associated Localization of Deformation and Fluid Flow in Fractured Rocks

Abstract

This chapter investigates the relations among the differential stress, mean stress, and fluid pressure and explores the critical behavior of a wide range of simulated fracture network. It examines the behavior of three natural fracture networks, where deformation leads to a pronounced change in both the magnitude and localization of flow, to systematically explore the effects of some aspects of network geometry on the instability and characterize the critical state in terms of the stress and fractal properties of the resulting fluid flow. The chapter also quantifies the effects of loading direction on the instability of the three specific networks. Numerical analysis is used to evaluate the critical stress state at which the instability occurs. A fractured rock mass is considered as a system of deformable blocks of rocks separated by interfaces, usually occupied by a fluid.