Deformability Modulus of Rock mass: In-Situ Tests

Rock mass deformability modulus is preferably determined from results of in situ tests, such as large flat jacks or borehole dilatometer tests. Since in-situ rock testing has become less common in recent years, the presentation in this post offers a comprehensive overview of traditional in-situ testing methods used to determine the deformability modulus of rock masses. This post is intended to help readers recall the origins and context of the empirical databases from which many of the formulations presented in this document were developed.