Within the framework of the feasibility study for a radioactive waste repository in a geological formation, the National Radioactive Waste Management Agency of France is constructing an underground research laboratory within the Callovo-Oxfordian argillite formation located in eastern France. During the sinking of the laboratory's access shaft and during excavation of the galleries, the mechanical and hydromechanical behavior of the argillite was monitored. A vertical mine-by test was carried out at depths between 460 m and 476 m in the main shaft. 12 boreholes were drilled downwards from a niche, where deformations and pore pressures were monitored. Another 11 boreholes were instrumented with mechanical and hydraulic sensors in the galleries. This paper is devoted to the instrumentation, the installation procedures and some first measurement results regarding the mechanical disturbance of the rock around the shaft.
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