Evaluating RBM Performance Considering the Geometric Parameters of the Raise Borer Machine and the Geomechanical Properties of the Rock
Authors
Abstract
In recent years, there has been a tendency towards mechanized drilling due to safety, high rate and efficiency, and environmental compatibility. Raise Boring Machines (RBM) are used for the mechanized drilling of shafts and other inclined structures in civil and mining projects. Choosing the type of RBM and accurately estimating the functions are the main parameters that affect the cost estimation and planning of mining and construction projects. This study aims to calculate the RBM performance considering the geometric parameters of drilling and based on the geomechanical properties of the rock. In this research, drilling the chief shaft in the Azad Dam in Iran has been evaluated using theoretical approaches and the cutting geometry of cutters. Shaft depth and diameter are 510 and 1.5 meters, respectively. The findings of this study showed that the rates of thrust force, machine power, and predicted torque are 4116KN, 125KW, and 199KNm, respectively, which are close to the actual value and proportional to the capacity of RBM. As a result, the device’s operating parameters have been compatible with the characteristics of the rock mass. Results showed that the rock’s uniaxial compressive strength and the roller cutter’s characteristics could determine the thrust rate behind the spindle and the amount of torque required. However, the accuracy and reliability of the proposed models should be improved with different rock types and RBMs with different sizes and capacities.
