A study of the relationship between saturated zone response and longwall mining-induced ground strain

The effects of longwall mining operations on near-surface water are not well understood. The sparse information that is available indicates a correlation between the proximity of the approaching longwall face and fluctuations in observation water wells. Furthermore, the magnitude of mining-induced subsidence appears to coincide with the degree of water level fluctuation. To provide additional information about these effects, the US Bureau of Mines has been installing well arrays over select longwall operations and observing the change as mining progresses through the area. Studies have been conducted at mine sites located in Pennsylvania and Ohio. The results of the research suggest that a relationship exists between water level fluctuations and the ground strain developed by the approaching longwall face. This paper explores research conducted at three mine sites and explains both the magnitude and timing of the observed water level fluctuations as a function of longwall mining-induced ground movement