关键词: 煤巷, 综放, 支承压力, 桁架锚索, 偏应力

Abstract: Sever underground pressure phenomena such as roof caving, sides collapse and support damage frequently occur in the surrounding rocks of coal roadway with fully-mechanized caving during the process of excavation as a result of sever mining dynamic load resulting from large-scale fully-mechanized caving. Those roof and support behaviors have a very bad influence on the safety and transportation of gob-side entry. With Return Airway 20102 in Wangjialing Coalmine as research subject, a combined method of site investigation, theory analysis, numerical simulation and in-situ tests was used to research the mechanism of sever strata behaviors, and the rework technology was put forward. The cause of its failure was summarized as follows: fracture development and low strength, high abutment pressure, large cross-section and unreasonable support. The dynamic process of deformation and failure was concluded as follows: the large-scale fully-mechanized caving leads to the high abutment pressure and the strong storage of stain energy, and the excavation of roadway causes the strain energy released strongly, which leads to severe instability and failure of the roadway; meanwhile the unreasonable support and the large cross-section aggravated the instability and failure. The control principle of excavating and mining was proposed, and the support scheme was determined according to combining geological production. Field practice has shown that after the application of comprehensive control technology, the surrounding rocks of coal roadway remain in a stable state with roof convergences of roadway no more than 136 mm, sides convergences of roadway 116 mm and floor convergences 132 mm.

Key words: coal roadway, fully-mechanized caving, abutment pressure, cable truss, deviatoric stress