Constitutive model equation for various types of rock specimen subjected to uniaxial compression loading

摘要

Right from the outset of the experimental determination of rock stress-strain response, researchers are performing uniaxial and tri-axial compression testing on the cylindrical specimens. In the last two-three decades' researchers have made an attempt to develop constitutive model considering anisotropy, rheological behavior and flaws in rock. In this project, static uniaxial compression tests are performed on cylindrical specimens of Kota sandstone, dolomitic limestone and three weathering classes of Delhi quartzite. Stress-strain curves have been plotted and a general constitutive model equation is derived for all the rock specimens. By observing stress-strain plot of different rock specimen, a parabolic relation between stress and strain is proposed containing two parameters m and n. The fitted results by these models for all types of rock are compared with the experimental data and with the Hooke's law. It is concluded that the amended damage constitutive model can describe the stress-strain behavior of rock quite accurately.