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The FEBEX (Full-scale Engineered Barriers Experiment in Crystalline Host Rock) ''in situ'' test was installed at the Grimsel Test Site underground laboratory (Switzerland) and is a near-to-real scale simulation of the Spanish reference concept of deep geological storage in crystalline host rock. A modelling exercise, aimed at predicting field behaviour, was divided in three parts. In Part A, predictions for both the total water inflow to the tunnel as well as the water pressure changes induced by the boring of the tunnel were required. In Part B, predictions for local field variables, such as temperature, relative humidity, stresses and displacements at selected points in the bentonite barrier, and global variables, such as the total input power to the heaters were required. In Part C, predictions for temperature, stresses, water pressures and displacements in selected points of the host rock were required. Ten Modelling Teams from Europe, North America and Japan were involved in the analysis of the test. Differences among approaches may be found in the constitutive models used, in the simplifications made to the balance equations and in the geometric symmetries considered. Several aspects are addressed in the paper: the basic THM physical phenomena which dominate the test response are ARTICLE IN PRESS www.elsevier.com/locate/ijrmms 1365-1609/$ -see front matter r

The permeability of intact Barre granite is determined by conducting transient hydraulic pulse tests that induce radial flow in saturated granite cylinders containing a water-filled co-axial cavity. Saturated specimens of granite are also subjected to uniform heating on the outer cylindrical surface and the permeability of the granite is measured at the termination of a heating sequence. The theoretical basis for the use of simplified analytical solutions for evaluating the decay of the pressure pulse is examined and the permeability of the granite in the pre-heating and post-heating states is inferred from the results of pulse tests. The reported investigations document one of the limited numbers of large-scale laboratory tests conducted to determine the permeability characteristics of intact granite. The results of the permeability measurements indicate the absence of any appreciable influences of micro structural alterations in the fabric of the granite due to its heating in a saturated condition, at an average temperature of 140°Celsius.

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