Deformation mechanism of roadways in deep soft rock at Hegang Xing’an Coal Mine

Abstract

Engineering geomechanics characteristics of roadways in deep soft rock at Hegang Xing’an Coal Mine were studied and the nature of clay minerals of roadway surrounding rock was analyzed. This paper is to solve the technical problems of high stress and the difficulty in supporting the coal mine, and provide a rule for the support design. Results show that mechanical deformation mechanisms of deep soft rock roadway at Xing’an Coal Mine is of IABIIABCIIIABCD type, consisting of molecular water absorption (the IAB-type), the tectonic stress type+gravity deformation type+hydraulic type (the IIABC-type), and the IIIABCD-type with fault, weak intercalation and bedding formation. According to the compound mechanical deformation mechanisms, the corresponding mechanical control measures and conversion technologies were proposed, and these technologies have been successfully applied in roadway supporting practice in deep soft rock at Xing’an Coal Mine with good effect. Xing’an Coal Mine has the deepest burial depth in China, with its overburden ranging from Mesozoic Jurassic coal-forming to now. The results of the research can be used as guidance in the design of roadway support in soft rock.