Abstract:

In order to study the impact of different tectonic stress zones of Maiduoshan coal mine on the mining engineering and mine dynamic disasters, the ground stress of the No. 6 coal seam of Maiduoshan coal mine was measured by the hydraulic fracturing method. A database of the lithology of the roof of the No. 6 coal seam of Maiduoshan coal mine and a model of the geological structure of the coal rock were constructed, and the stress distribution and zoning characteristics of the mine field of Maiduoshan coal mine were determined by the rock stress state analysis system. The results show that Maiduoshan coal mine belongs to a typical slip-type stress field, namely a tectonic stress field dominated by horizontal stress, with a maximum principal stress of 15.02 MPa and a direction of N15.6°E. The mine field is divided into four stress zones, namely, high stress zone, stress gradient zone, stress normal zone, and low stress zone, accounting for 7.5%, 8%, 57.5%, and 27% of the area of the mine field, respectively. In the high stress zone and stress gradient zone, the superimposed influence of mining disturbance can easily lead to the occurrence of roof falls and heaving floor in the roadway, in the stress normal zone and low stress zone, the roadway is less influenced by the stress of the original rock, which is not easy to produce the energy accumulation, and the danger of roadway damage is reduced. For the roadway that is being dug and not put into use, the monitoring and support of the roadway surrounding rock should be strengthened according to the characteristics of the stress zones, so as to realize the hierarchical and zonal management of coal mining engineering and disaster prevention and control and guarantee the safety of coal mine production.

Key words: in-situ stress measurement, maximum principal stress, stress zone, tectonic stress field, roadway surrounding rock