Terzaghi's concept of rock load on tunnel supports does not account for the squeezing of rocks due to high geostatic or tectonic stresses. Recent theories, based on elastoplastic analysis, may explain the phenomena of squeezing pressures. However, these theories have not been varified by field studies. Certain data have been collected through measuring devices in the sections of a tunnel under construction in Himachal Pradesh where monitoring of tunnel deformation, load on supports and the displacements in plastic zone around the opening have been made. The tunnel under reference was excavated through soft and crushed rocks and a reduction in the diameter upto 17 percent was observed in the critical sections where the horizontal pressures and closures were more than twice the vertical ones.

Media Info

  • Pagination: p. 39-44

Subject/Index Terms

Filing Info

  • Accession Number: 00178104
  • Record Type: Publication
  • Source Agency: Engineering Index
  • Files: TRIS
  • Created Date: Sep 27 1978 12:00AM