Shear-flow coupling tests are conducted using an original apparatus, and a shear-flow coupling model using Geographic Information System (GIS) is developed in order to evaluate shear-flow coupling properties of a rock joint. Shear-flow coupling tests indicate that the hydraulic conductivity of joint once decreases, and then rapidly increases at the shear displacement near the peak shear stress. The proposed model simulates the test results relatively well. However it indicates that it is difficult to apply the local 'cubic law' model in the initial shear stage, in which the change of selective flow path is remarkable.

Scher-Fliess-Kopplungsversuche werden mit einem neuartigen Versuchsgerat durchgefuehrt und mithilfe von Geo-Informationssystemen (GIS) gedeutet, um so ein Modell fuer die Scher-Fliess- Kopplung in Gebirgstrennflachen zu entwickeln. Die Versuche zeigen, dass die hydraulische Leitfahigkeit zuerst abnimmt, dann aber schnell wieder zunimmt sobald die maximale Scherfestigkeit erreicht ist. Das vorgestellte Modell bildet die Testergebnisse relativ gut nach. Es zeigt auch, dass es schwierig ist, das lokale Cubic Law im Initialstadium der Scherbeanspruchung anzuwenden, in dem die Variationen selektiver Fliesswege gross ist.

Les essaies hydro-mecaniques couples en cisaillement sont realises grace à un appareil experimental prototype et un modèle de couplage hydro-mecanique utilisant le S.I.G (systeme d'information geographique) developpe dans le but d'evaluer les proprietes hydro-mecaniques des joint rocheux. Les resultats indiquent que la conductivite hydraulique des joints decroit puis augmente rapidement en se rapprochant du pic de cisaillement. Le modèle propose simule relativement bien les resultats experimentaux; mais indique egalement qu'il est difficile d'appliquer localement la loi cubique au debut du cisaillement où, les changements d'orientation dans le reseau d'ecoulement sont considerables.

Introduction

Deep underground structures utilize rock characteristics such as stiffness, sealing, durability and isolation. From the point of safety, economics and environmental influence, more severe design conditions are required and more accurate properties of rock mass are needed. Specifically, it is important to obtain the permeability of the rock mass, in which underground structures are to be constructed in order to confirm its capacity to isolate. Permeability in rock masses containing multiple joint sets is principally governed by those joints. Since the permeability of a rock joint fundamentally depends on its behaviour in opening and closing, it is necessary to understand the coupling between the hydraulic and mechanical mechanisms. The behaviour of a rock joint is complicated because both normal and shear stresses act on the joint. Consequently, there are few data on shear-flow coupling properties, because of the intrinsic complexity of this coupling phenomenon 1.

In this study, the shear-flow coupling properties of a rock joint are clarified from laboratory tests. A shear-flow coupling model using a Geographic Information System (GIS) is developed, and the shear-flow coupling tests are simulated in order to clarify the mechanisms of shear-flow coupling properties.

Shear-flow coupling properties of a rock joint

A shear-flow coupling test apparatus has been developed that is capable of completing a 1-dimensional flow test during the shear test 2.

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