The analysis of geomechanical behavior for granular systems including fluid-filled pores depends strongly on the crack density present within the system being studied. Effective overall bulk and shear moduli are both significantly influenced by these crack system parameters. Present effort concentrates on the geomechanical analyses needed to treat anisotropic (specifically orthotropic) poroelastic grains jumbled together to form an overall isotropic polycrystalline poroelastic material. As predicted, poroelastic effects induced by fluids in the cracks are observed to be significant for the effective bulk modulus, but simple pore fluids do not affect the magnitude of effective overall shear modulus. These results are also shown to depend in a quantitatively predictable way on crack density values. Copyright © 2014 John Wiley & Sons, Ltd.