25 MPa HyperPac Fills the Gap Between the Ménard Pressuremeter and the Flexible Dilatometer

The borehole expansion test can be used in any ground material, from the softer to the harder one, so as to obtain its stress–strain behaviour in situ. The authors submit their research work on equipment which permits to extend the use of the Ménard pressuremeter up to 25 MPa test pressure. They also give the first test diagrams up to this pressure in slightly fractured rocks.