A determination method for rock salt deformation parameters

In order to determine the deformation parameters of salt rock more accurately, the formula for calculating the rock salt deformation parameters determined by the conventional triaxial compression tests was deduced according to the elasticity theory. Uniaxial and triaxial compression tests were carried out on the rock salt specimen of one certain salt cavern underground gas storage. The deformation parameters obtained by two different test methods were comparatively analyzed. Furthermore, the influence of the selection of different deformation segments in the stress-strain curve on the deformation parameters was studied when determining the deformation parameters of salt rock on the basis of the uniaxial compression test. It is shown that when the stress-strain increment of initial elastic deformation stage is used to calculate the rock salt deformation parameters, the result obtained through triaxial compression test is much closer to actual value. There is a greater deviation between the elastic modulus and shear modulus of salt rock determined on the basis of uniaxial compression test and the actual values, and elastic deformation parameters corresponding to 5% - 10% compressive strength are more accurate than those to 10% - 30% compressive strength. The research results provide a reference for the reasonable determination of rock salt deformation parameters.