Abstract: To solve the control problem in a series of nonlinear rheological large deformation phenomena such as serious floor heaves and section shrinkage of the south limb soft rock roadway in Yangcheng coal mine, the surrounding-rock geomechanical properties and failure characteristics were analyzed with the methods of mechanical testing, theoretical analysis and field test. By establishing roadway mechanical model under biaxial uniform loading, the deformation and failure mechanism of the south limb soft rock roadway were studied and revealed. The results have shown that ground stress environment has a very adverse effect on the soft rock roadway, the surrounding-rock of the roadway is HJS composite soft rock, and the small complete strata thickness owing to joint fissures and loose damages of the surrounding-rock is the key factor for severe failure of the roadway. Based on the complex failure mechanism of the soft rock roadway, the combined supporting was put forward through bolting, metal net, guniting, and grouting with bolting and grouting support as the main method. In addition, a new grouting cable anchor was designed and applied. Deep and shallow coupling grouting was realized by the grouting bolt and the new grouting cable anchor. Finally practical engineering has shown that the combined supporting was effective and the large deformation of soft rock roadway was effectively controlled. The achievement of deformation control of the south limb soft rock roadway in Yangcheng coal mine provided an important reference for the similar roadway project.

Key words: deep level, composite soft rock roadway, deformation and failure mechanism, bolting and grouting support, grouting cable anchor