This paper puts forward that the displacement of the reinforced cracked wall rock has variability in direction

periodicity of destroy and otherness of velocity variety

according to the whole process observation of convergence of the analysis of rock hole poly-point displacement. The process of distortion can be divided into three phases of the sharp distortion

regulative distortion and slow distortion. The paper indicates that the displacement of rock mass may change direction in regulative distortion phase; the displacement presents periodicity according to the storing and the destroy of the energy of rock distortion; the quantity of displacement of the top is more than that of the bottom; the quantity of displacement and the destroy periodicity of the terrain reinforced with cement injection are less than that of the unreinforced terrain

the convergence of boardrooms is the displacement of certain thickness wall rock of surface layer. The key technique is to consider fully the effect of faultage construct and to design the thickness of reinforced terrain and the form of closed shells according to the stress field.