Abstract
This paper proposes a reliable method for estimating Mohr-Coulomb strength parameters c and φ from a load-displacement relationship obtained by plate loading and borehole loading tests. Strength parameters c and φ are back-calculated so that those minimize the difference between measured and calculated displacements which are based on a hyperbolic type of stress-strain model. The incremental method for non-linear stress-strain analysis and the simplex method for optimization are respectively employed. It is possible to estimate c and φ separately from a load-displacement relationship usually measured by in-situ test since c and φ affect the load-displacement relationship in a different manner.
