Rock Mass Deformability by Extra Large Flat Jack, Plate Load and Dilatometer Testings

Procedures for calculating rock mass deformability moduli from the results of in situ testings are encumbered with crudity that should be taken into account in all steps of the planning and performance of testings. A critical review of in situ tests most often used is made with emphasis laid on problems concerning an interpretation of results of measurement. Experiences with twenty-eight PL, seventeen ELFJ and more than one hundred dilatometer tests are presented.