In order to reduce the resistance of hard rocks to excavation by available cutters, and in order to reduce wear on cutters and thus to increase the efficiency of conventional tunneling machines and thus improve their rate of advance in hard rocks, surface active agents have been studied in controlled laboratory environments and have been experimented with in the field in actual tunneling operations. The laboratory study utilized a notched beam test to measure the effectiveness of thirty different surface active agents on the amount of surface energy required to cause stable fracture in rock specimens. In addition to the type of rocks, geometry of the specimens, type of surface active agents, the effect of environment such as temperature and degree of saturations were studied.

Media Info

  • Media Type: Digital/other
  • Pagination: 49 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00054329
  • Record Type: Publication
  • Source Agency: National Technical Information Service
  • Report/Paper Numbers: FRA-RT-73-22 Final Rpt
  • Contract Numbers: DOT-C-85-65
  • Files: TRIS
  • Created Date: Jun 10 1974 12:00AM