TRANSIENT POROELASTIC RESPONSE OF EQUIVALENT POROUS-MEDIA OVER A MINING PANEL

A transient poroelastic formulation based on the Biot consolidation th eory is presented to study the impact of underground longwall mining o f coal on strata deformation and the subsequent modification of hydrog eological properties. A finite-element model is used where the geometr ic conditions may be complex. The important parameters in this model a re identified as pore pressure ratio, alpha1 and relative compressibil ity, alpha2 with the latter exerting far greater influence on the resu lting fluid pressure field than the former. This study indicates that the fluid pressure distribution is strongly controlled by the stress d istribution, or the strata deformation induced by mining has a great i mpact on the change in hydrogeological environment in the mining regio n.