Development of discharged soil measuring device for shield tunneling machines

Abstract It is very important to know the volume of discharged soil for more adequate excavating control of the shield tunneling machines. In confined soil shields and mechanical shields, excavated soil is discharged by belt conveyors and muck cars, so it has been difficult to evaluate the discharged soil volume. In this study we have developed a discharged soil measuring system to evaluate the volume of discharged soil in real time. This system is equipped with (1) an ultrasonic sensor or (2) light section microscope with a laser to measure the cross-sectional area of transported soil on a belt conveyor. Using this system, it is possible to evaluate the volume of discharged soil with good accuracy in a very humid environment like a shield tunneling machine. This system is effective not only for measurement of soil flow volume but also for measurement of volume in belt conveyor systems for granular material such as coal and powder such as flour.