Study on law of in movement and deformation under downward mining in contiguous coal seams

In order to study the formation, movement, and energy exchange of the broken roof in the process of mining contiguous seams, a two-dimensional physi cal simulation model was bult. Based on integrated monitoring of total station instrument, dial gauge and thermal infrared imagine, as well as theoretical analysis the ca uses of broken roof structure and its characteristics of rock mass development. The results show that during downward mining in close-distance seams, the damage de pth to the secondary seam is 10.05 m; mining the third coal seam will caused induced disturbance on the stability of the strata, and subsidence amount is 0.39 m; the h eight of broken roof seam is 21.9 m. The conclusion is made that the load of support is composed of static load and dynamic load when disturbance from broken roof str ucture is at present. To ensure the support strength at the working face, the support resistance of the hydraulic support and setting load should be increased. To improv e the integrity and bearing capacity of broken loose layer, an artificial roof can be made by applying steelwire reinforcement, or pre-grouting to stabilie and solidify the roof. .