The hyperbolic model is a simple stress-strain relationship based on the
concept of incrementally nonlinear elastic behavior. The hyperbolic stress-strain
relationship was developed for use in finite element analysis of stresses and
movements in earth masses. To estimate hyperbolic parameter values required for
nonlinear finite element analysis, data used from the triaxial compression tests for
the gypseous soils exposed to the effect of drying and wetting cycles carried out by
(Mohammed, 1993). From these data, the parameters (C, φ, K, n, Rf), which are
required by Duncan-Chang model, 1970 can obtained for analyses of dams,
excavations and various types of soil-structure interaction problems.
In addition, it can be found that the primary loading modulus, K, the
exponent number, n, and the failure ratio, Rf, have random values during rewetting
cycles for CU and UU triaxial compression tests