ROCK STRENGTH FROM FAILURE CASES: LEFT BANK SLOPE STABILITY STUDY - LIBBY DAM AND LAKE KOOCANUSA, MONTANA

Slope stability problems involving fault and joint bounded rock masses occurred in the left abutment and left bank areas of Libby Dam during recent construction of the dam and related facilities. These problems were investigated by the Seattle District and Waterways Experiment Station, Corps of Engineers, and by the writer. Results of these investigations are summarized in this report where emphasis has been placed on determination and interpretation of in situ shear strengths for geologic discontinuities in hard rock slopes. It was impossible from a practical standpoint to obtain the degree of geologic information needed to reliably evaluate the stability of left bank ribs. This is largely because of the size of the ribs and the complexity of their structural geology. Despite this lack of geologic information, several conclusions of practical importance were drawn from the writer's investigation. These conclusions are related to (1) failure conditions for small rock wedges, (2) in situ shear strength parameters for geologic discontinuities, and (3) left bank rib stability. /AUTHOR/

  • Corporate Authors:

    Missouri River Division, Army Corps of Engineers

    Geology Soils and Materials Branch
    Omaha, NE  USA  68101
  • Authors:
    • Hamel, J V
  • Publication Date: 1974-7

Media Info

  • Features: Appendices; Figures; References; Tables;
  • Pagination: 170 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00264296
  • Record Type: Publication
  • Report/Paper Numbers: MRD-1-74 Tech Rpt.
  • Contract Numbers: DACW 45-70-D-0071
  • Files: TRIS
  • Created Date: Dec 19 1974 12:00AM