Laboratory measurement of the hydraulic conductivity of various rock types revealed that the hydraulic conductivity sensitively changes as the porosity and the stress state in the rock change. This effect becomes clear when the porosity and various principal stresses are increased. Review of the previous laboratory experiments indicate that the hydraulic conductivity of various rock types ranged between the order of 1O-11cm/sec and 100cm/sec, and it decreases as pore pressure decreases, confining pressure increases and intermediate principal stress increases.
The variation and distribution of hydraulic head and hydraulic gradient within a specimen were evaluated by a general equation which describes the transient pulse test. The hydraulic gradient during the early stage of the transient pulse test remarkably increased at around the upstream end of the specimen. As the time elapsed, the hydraulic head at the upstream side gradually decreased, whereas that at the downstream side monotonously and gradually increased.
