Correlation of Geomechanical and Dynamic Elastic Properties with the P-Wave Velocity of Lower Gondwana Coal Measure Rocks of India

Abstract

Ground behavior during surface and subsurface coal mining activity is primarily governed by the geomechanical and elastic properties of the encountered rocks. A quick estimation of these parameters would provide an advantage to various mine design operations. However, a direct method to determine these parameters is, in general, expensive, laborious, time-consuming, and requires precision and experienced labor. In this paper, a quick, easy, indirect, and nondestructive method is proposed to determine the geomechanical and dynamic elastic properties of Lower Gondwana coal measure rocks from eight different coal mines in three coalfield regions of the Damodar and Mahanadi coal basins in India. The uniaxial compressive strength (UCS), Brazilian tensile strength (BTS), density (ρ), and dynamic elastic properties including the dynamic Young’s modulus (ED), dynamic shear modulus (GD), dynamic bulk modulus (KD), and dynamic Poisson’s ratio (μD) were determined and correlated with the P-wave velocity for sandstone and shale rocks to yield empirical correlation equations. Finally, a comparative regression analysis was performed to characterize the Lower Gondwana sandstone and shale and the regressions were statistically tested using the Student’s t-test.