ln Situ Testing of Rock Masses for Tunnelling

Abstract

To make known the capabilities of LNEC to assist tunnel designers, in the domain of in situ measurements with a bearing on the steps of design and control/supervision of underground construction, a few methods are described, which have been developed by the Laboratório for characterizing the deformability and apprasing the strength of rock masses, as well as for determining the states of stress occurring in them.

ln particular, a discussion is presented of the use of the dilatometer and stress tensor gauges in boreholes, and of thin flat jacks in test slots cut in rock masses.