Accession Number : AD0738130

Title :   Investigations Aimed at the Development of an Efficient Rock Excavation for Driving-Machinery in Hard Rock (Untersuchungen Gesteinsangriff von Vortriebsmaschinen fuer Hartes Gestein),

Corporate Author : COLD REGIONS RESEARCH AND ENGINEERING LAB HANOVER N H

Personal Author(s) : Hendriks,Heinz

Report Date : JAN 1972

Pagination or Media Count : 34

Abstract : With simple rotary cutters it is possible to achieve an advantageous method of rock excavation at a free surface if the rotary cutters are mounted either in step-wise configuration on a conical drill-head with concentric cutting paths or mounted on a drill-head having planetary-type circulating drill-tool carriers and cycloidal cutting paths. For these methods of rock excavation, in drilling experiments which closely approximated actual practice, measurements were made on a test stand of the cutting forces affecting the rotary cutters for various penetration depths. The observations show that the advantage of rock excavation at a free surface consists above all in the fact that one can attain very high drilling velocities with comparatively low penetration forces. Moreover, this method of excavation also reduces the specific energy cost. (Author)

Descriptors :   (*UNDERGROUND STRUCTURES, *DRILLING MACHINES), CIVIL ENGINEERING, ROCK, PENETRATION, COSTS, WEST GERMANY

Subject Categories : Civil Engineering
      Machinery and Tools

Distribution Statement : APPROVED FOR PUBLIC RELEASE