Hydro-mechanical response of a fractured granitic rock mass to excavation of a test pit - the Kamaishi Mine experiment in Japan

A thermo-hydro-mechanical experiment was conducted in a fractured granitic ruck mass at the Kamaishi Mine in Japan. The experiment consists of the exc avation of a cylindrical test pit on the floor of an experimental drift. Th e test pit was then lilted with bentonite with an embedded heater. During t he excavation of the test pit, the hydromechanical response of the surround ing rock was monitored. This paper presents the efforts of four research te ams to numerically simulate the hydro-mechanical response of the rock mass during excavation. While the total inflow rate to the test pit, the flow di stribution on the pit walls and the displacements in the rock mass away Fro m the pit could be reasonably predicted, the pore pressure in individual bo reholes, and the expansion behaviour of the pit were less successfully simu lated. The reasons for these discrepancies are discussed in the paper. (C) 2001 Elsevier Science Ltd. All rights reserved.