Calculating Components of the Effective Tensors of Elastic Moduli and Biot’s Parameter of Porous Geocomposites

Abstract

Methods of composite mechanics were used to evaluate the effective elastic moduli and Biot’s parameter of porous media. Natural composites — dolomites and hyaloclastites — were considered as examples, which were also examined experimentally. The microscopic structure of the rocks was studied under a microscope, and their mineral composition was determined by the X-ray diffractometry. A comparison of experimental and calculated elastic moduli of dolomites showed their good agreement, which proved that the averaging method can be used to rapidly evaluate their effective elastic properties. For dolomites, Young’s modulus and Biot’s parameter were determined as functions of porosity using the calculation results and experimental data. The computation method described in this paper allows one to calculate Biot’s tensor in the general case of an anisotropic and inhomogeneous matrix and to evaluate the influence of pore shape on stresses and strains at the microlevel, which is not possible by experimental methods. Using samples of hyaloclastites with round and angular pores, the effect of pore shape on the elastic moduli and the effective stress coefficient was investigated. The effect of pore orientation was also studied using anisotropic dolomite samples with elongated pores.