Differences of hydraulic conductivities from pumping and draining tests with intensity effects

Pumping tests are the most commonly used method for obtaining hydraulic conductivities in mine hydrogeological work, while draining tests are a new hydrogeological test method in recent years. However, the hydraulic conductivities obtained from draining tests are different in some extent from those from pumping tests. Sometimes the differences are even of an order of magnitude. In this paper, the draining tests are carried out in 5 coal mines, the corresponding pumping test data are collected, the data are compared and analyzed in several aspects, and the fractured aquifer is taken as an example for theoretical analysis. After analysis and discussion, it is found the main reason for the differences is intensity effects. Since the amount of the water used in draining tests is much larger than that in pumping tests, some of the ineffective fissures occupied by capillary water and bound water are converted into effective fissures, resulting in an increase in hydraulic conductivities. Therefore, intensity effects on hydraulic conductivities are of great theoretical significance in hydrogeological research.