Atlas Copco has introduced a sophisticated geotechnical integration module for its underground tunneling drill jumbos, shifting the focus of automated drilling from mere positional accuracy to active rock mechanics analysis. In conventional tunnel excavation, operators drill a predetermined pattern of holes based on surface core samples, which often fail to accurately represent the actual rock mass hundreds of meters below. Atlas Copco's new platform utilizes Measurement While Drilling (MWD) technology to read the rock in real-time and dynamically alter the drilling parameters.
The system works by continuously monitoring the drill rig's percussion pressure, feed force, rotation torque, and penetration rate at a frequency of 100 times per second. As the drill string advances into the tunnel face, these parameters create a highly detailed geological profile of the rock mass. If the MWD algorithm detects a sudden drop in penetration rate combined with a spike in rotation torque, it identifies a transition from solid granite to a fractured fault zone. Rather than forcing the drill bit through the unstable rock and risking bit seizure or borehole collapse, the control system automatically reduces the percussion pressure and increases the flushing water flow to clear the debris.
Furthermore, this geotechnical data is instantly fed into the tunnel's blast design software. By mapping the hardness and fracture lines of the face, the software recalculates the required explosive charge for each hole. In softer, highly fractured zones, the system automatically reduces the specified powder factor, preventing over-breaking the tunnel perimeter and minimizing the costly shotcrete required to stabilize the walls.
Field trials in a deep Alpine base tunnel demonstrated a 15% reduction in over-break (the unwanted excavation of rock beyond the design profile) and a noticeable extension of drill bit life. By turning the drill string into an active geological sensor, Atlas Copco is allowing contractors to adapt their excavation strategy on a meter-by-meter basis, significantly lowering ground support costs and accelerating overall tunneling progress.
