Abstract
Estimation formula for rock mass deformability in borehole jack test initially derived by Goodman has been modified by Hustrulid and Amadei et al. But their solitions are approximately obtained as the first fundamental problem. This paper presents forrnula from the exact solution by the mixed fundamental problem. In the latter half, Numerical calculation by their approximate and our exact solutions are performed and quantitative differences between them are shown by graphical representation.
