Study on technology of anchor concrete- filled steel tube supporting structure in roadway with high stress

In order to solve the problem of large- scale and repeated deformation of second level auxiliary haulage roadway in some coal mine,the fracture developing characteristic of surrounding rock was obtained by dilling hole camera,based on which the stress and displacement of surrounding rock were measured with specially desi gned force anchor bolts. The results showed that anchor bolts would curve and fail under the combined effect of stretch,compression and shear around fracture. The shear failure would occur in surrounding rock with high level ground stress. The relatively slipping of fractured block after shearing failure of surrounding rock was the root cause of intensively and persistent deformation of roadway,according to which the anchor concrete- flled steel tube supporting structure which obtained advantages such as high pre- stress,high anchorage force and high anti- shear strength was proposed. Ultimately,combined supporting scheme of anchor concrete- flled steel tube supporting struct ure with reinforced concrete was made and industrial test was carried out. The displacement observation result showed that deformation of test section roadway was only 5 0 ~ 82 mm. The problem of continuous,repeated and large- scale deformation of second level auxiliary haulage roadway.