Study on Composite Wall Support Technology Applied to Gob-side Entry Retaining

In order to solve a large deformation of mine gateway and mine strata pressure bump caused by the overhigh advance support pressure of the gateway r etained along the goaf in a deep coal mining face, a composite wall roadside support technology was provided based on a sectional and stage loading principle. The Co mposite wall mainly was a coal refuse brick wall as the main wall mass and an inorganic backfill material Ruimi No. 3 as auxiliary wall mass. With a dynamics analysis C onducted on a roof of the gateway retained along the goaf, the roof subsidence value and the wall support strength were calculated. The lab experiment showed that th e support strength of the coal refuse brick was 10. 4 MPa and could fully meet the roof pressure born by the wall mass. The designed height of the auxiliary wall mass was0.4 m, could meet the requirement of the yield pressure and could ensure the support role of the main wall mass. The results showed that the composite wall suppo rt technology could effectively control the deformation of the gateway, could prevent the mine strata pressure bump accident occurred, could solve overhigh advance su pport pressure of the gateway retained along the goaf in the coal mining face and could solve the environment pollution problems by the coal refuse.