Tunnel, Raise and Shaft Boring Tests
A six-foot diameter, computer-controlled rotary cutting machine with removable cutters and cutterhead performs tunnel, raise and shaft boring investigations. The machine is pivoted on an anchor frame so that it can be tilted to any desired direction. The machine is used in laboratory studies to develop design guidelines to optimize tunnel, raise and shaft boring performance. All machine operative functions are servo-controlled and run by a computer system. The capacity is one million pounds of thrust and 200,000 foot-pounds torque with cutterhead speed variable up to 55 rpm. Instrumentation includes monitoring of individual cutter forces in three directions, as well as measuring all machine parameters during cutting. The machine can also be fitted with water jets to perform water jet-assisted mechanical cutting tests. The machine can also be used to run dust suppression and muck removal tests.