Abstract: The roadway experienced the whole evolution process, including the stability before excavation, excavation disturbance and support stability or failure. It is found that the steady state of the roadway was affected by the interaction of the in-situ stress field, excavation-induced stress field and supporting stress field. In this study, the finite difference program FLAC3D was employed to analyze distribution characteristics of supporting stress fields in surrounding rock which were induced by the bolt and anchor cable under different conditions of pre-tightening force and inter-row distance. Furthermore, the coefficient k of rock stress expansion was defined to characterize the stress diffusion effect of surrounding rock. The coupling support effect of the bolt and anchor cable was revealed as well. A new approach was put forward by considering the special geological conditions and engineering characteristics of deep roadway in Zhujixi Mine. This approach was named as a step-by-step combined support technology consisting of cable anchor spraying, U type steel support, grouting, floor anchor and injection. A three-dimensional (3D) similar material model test was conducted to verify the approach, which revealed the deformation and failure of soft surrounding rock and the evolution laws of supporting structure under high stress conditions. This scheme was also successfully applied to a practical engineering project, which solved the support problem of deep soft rock roadway under high stress. The monitoring results indicate that the combined support scheme effectively control the large deformation and floor heave of deep soft rock roadway. Eventually, the long-term stability and safety of the roadway surrounding rock and supporting structure can be guaranteed.

Key words: high stress, soft rock roadway, coupling supporting effect, step-by-step combined support technology, similar material model test