Research on process and key technologies of raise boring

The raise boring is the most difficult and risky construction project for underground shaft sinking and drifting engineering. The process flow of pilot hole drilling and reaming drilling in the raise boring drilling process is summarized and analyzed. Key technical issues such as hob rock breaking, drill hole deflection control, drilling force characteristics and surrounding rock stability control during the raise boring drilling process. The atfhor condensed the key technical problems in the seven aspects of guiding hole drilling and reaming drilling in the raise boring drilling process as followings:The stress characteristics of the pilot hole drilling tools and the technology of the deflection control;The choice of well washing medium and the relationship between pressure, flow and other parameters and slagging effect;Influence and control technology of drilling parameters, well washing medium and stratum structure on surrounding rock stability during pilot hole drilling; Analysis of rock breaking method and arrangement of hob for reaming drill hob;The influence of tool-to-rock pressure determination, coordination between pressure and propulsion, energy consumption per unit volume of rock breaking, correlation between tooth wear and mineral composition, and reaming drilling efficiency; Influence of parameters such as creep, weathering, hydration, drilling diameter, drilling depth and exposure time on well stability and risk identification; Analysis of connection mode, force characteristics and fatigue failure characteristics of drill stem during reaming drilling. Meanwhile, the raise boring drilling equipment consisting of the host system, the drilling system, the cooling & dust reduction system, the auxiliary system and the problems faced by it are given. The standard system of raise boring drilling test platform research system and raise boring drilling technology, equipment and process is introduced. This provides theoretical guidance and technical support for engineering applications, equipment manufacturing, and design of key components for raise boring drilling.