Search U.S. government technical reports digitized or harvested by TRAIL.
Tunnel boring technology :disk cutter experiments in sedimentary and metamorphic rocks
Tunneling machine research :development of an experimental full-scale research rock cutting device
Tunneling machine research :interaction between disk-cutter grooves in rocks
Tunnel boring technology:disk cutter experiments in metamorphic and igneous rocks
Tunneling machine research :size distribution of rock fragments produced by rolling disk cutters
Overcoring equipment and techniques used in rock stress determination
Drillability determination :a drillability index for percussion drills
Mine power systems research(in four parts) :