Abstract:

Abstract: To effectively maintain the stability of large-scale coal drifts in extremely thick coal seam and to solve the problem of reasonably selecting surrounding rock’s parameters used in numerical simulation, analysis the real strength of roadway surrounding rock in different parts by laboratory test, field test and theoretical calculation, research the distortion and failure character of roadway based on the thought of “differ parameter”, and design method of support parameters based on loose circle theory consistent with the character. The calculation results show that the thickness of the loose circle is 1.51m, 1.57m and 1.6m from theoretical calculation, field measurement and numerical simulation, they are same basically; deformation of surrounding rock development to the roadway space no supporting, the roof prone holistic caving, surrounding rock displacement caused by the broken expansion deformation within rock loose circle; the numerical simulation reproduces the effect of a combination arch and match with the expected results and good engineering application results have been achieved, the loose circle support theory can good maintain the stability of large-scale coal drifts in extremely thick coal seam.

Key words: Key words: extremely thick coal seam, large section roadway, differ parameter, loose circle theory