Characterisation of Boom Clay anisotropic THM behaviour based on two heating tests at different scales in the HADES URL


 To examine the impact of the heat generated by high level radioactive waste on Boom Clay, two heater tests have been launched in the HADES underground research facility (URL): the small scale ATLAS Heater Test and the large scale PRACLAY Heater Test. The major objective of these tests is to confirm and refine the thermo-hydro-mechanical (THM) constitutive models and associated parameter values obtained from a laboratory characterisation programme.
 
 This paper presents the observations from the ATLAS and PRACLAY Heater Tests and the combined numerical modelling of these tests. To characterise the excavation damaged zone in the clay around these tests, a mechanical model with a strain dependent elastic modulus is introduced for the Boom Clay. The consistency between the observations from laboratory tests and
 in situ
 tests and the outcomes from the numerical models strengthens the confidence in our understanding of the THM behaviour of Boom Clay. It also enabled to validate the mechanical model and produce a set of anisotropic THM property values for both intact and damaged Boom Clay.
