Abstract:

In order to optimize the surrounding rock support scheme for the roadway of Maiduoshan coal mine, the in-situ test of ground stress and surrounding rock strength in the roadway of Maiduoshan coal mine was carried out. The structure of the surrounding rocks in the roadway was observed by the borehole peeping method, and its morphology was thus revealed. The appropriate measuring points were selected for the test of ground stress under hydraulic fracturing. The surrounding rock strength was tested by the borehole penetration method. The geomechanical distribution characteristics and mechanical parameters of surrounding rocks in the No. 6 coal seam of Maiduoshan coal mine were analyzed. The test results show that the average value of the maximum horizontal principal stress in Maiduoshan coal mine is 15.2 MPa, and that of the minimum horizontal principal stress is 8.17 MPa. The average value of the vertical principal stress is 13.94 MPa. The ground stress field in the test area is a medium stress value area. The average strength of surrounding rocks in the No. 6 coal seam in the region is 28.16 MPa, and the coal is relatively hard. In the range of 10 m of surrounding rocks in the roadway, there are siltstone, coarse sandstone, and siltstone in different depths. The strength of rock mass increases, and the strength of rock mass increases by 95.41 MPa at 4.9 m.

Key words: roadway of coal mine, geological mechanics test, hydraulic fracturing, surrounding rock strength, surrounding rock structure, ground stress