Effect of pore pressure on stress

Input(s)

$\lambda$: Lames First Constant (psi)

$\delta$: Kronecker Delta (dimensionless)

$\xi_{o}$: Initial Strain (dimensionless)

$\xi$: Final Strain (dimensionless)

G: Modulus of Shear (psi)

$\alpha$: Biot (dimensionless)

P: Pressure Applied (psi)

Output(s)

S: Stress (psi)

Formula(s)

$$ \mathrm{S}=\lambda * \xi_{\mathrm{o}} * \delta+2 * \mathrm{G} * \xi-\alpha * \delta * \mathrm{P} $$

Reference(s)

Mark D. Zoback, Reservoir Geomechanics, Cambridge University Press, UK, Page: 68.