ROCK ELASTICITY
It is often necessary for miners to take into account the resistance of rock bodies to compression and distortion when placed under stress. The ability of a body to resist forces is determined by elasticity.
The three moduli of elasticity are:
Young's Modulus: E= (Applied force/Area) / (Change in length/original length)
Shear Modulus: G= (Applied force/unit area) / (Angular deformation)
Bulk Modulus K= (Force/unit area) / (Change in volume/unit volume)
Young's Modulus measures the ablitity of a body to resist elongation or shortening.
Shear Modulus measures the ability of a body to resist a change in shape.
Bulk Modulus measures the ablitity of a body to resist a change in volume.