Influence of engineering parameters on rock breaking performance of raise boring machine

As a crucial rock crushing equipment, the raise boring machine (RBM) has been widely used in underground engineering construction, especially in the construction of shaft wellbores. Herein, experiments and measurements were carried out in a hydropower station construction project. By loading a set of engineering parameters, data from the four parameters of pulling force, torque, rotation speed and drilling speed of the drill pipe were obtained. The research results show that torque in the rock breaking process has no correlation with the rotation speed and is linearly related to the pulling force. Increasing rotation speed or pulling force can both clearly improve rock breaking efficiency; however the effect from pulling force is greater. This experimental method is able to find the best engineering parameters so that the RBM can obtain minimum energy consumption for rock breaking.