ROLE OF TOPOGRAPHY AND ANISOTROPY WHEN SELECTING UNLINED PRESSURE-TUNNEL ALIGNMENT

The authors of this paper show how analytical solutions can help in the selection of the alignment of unlined pressure tunnels near slopes and valley walls. The proposed solutions predict in-situ stresses in rock masses with smooth and irregular topographies. The technique can be applied to ridges and valleys in isotropic or anisotropic rock masses subject to gravity or to combined gravitational and tectonic loading. The two-dimensional analytical solutions assume plane or generalized plane strain and can be used to substitute existing design charts for pressure tunnels based on the finite-element method. The authors found that the safe alignment of unlined pressure tunnels depend largely on the extent of tensile regions in valley walls, which itself depends on parameters such as valley geometry, the degree of rock anisotropy, the orientation of the planes of rock anisotropy, and the in-situ loading conditions.

Language

  • English

Media Info

  • Features: Appendices; Figures; References;
  • Pagination: p. 879-885
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00714630
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Dec 18 1995 12:00AM