Soil investigations for a section of the Metro where existing major highway and bridge structures would leave relatively little cover over the tunnels revealed that the tunnels would have to be driven through mixed face, with a clay invert and a waterlogged sand crown. Thus, there was a good chance that the roof would fall in. The design settled on a scheme of grout injection to stabilize the granular soils and preclude the development of runs in the crown of the tunnel headings. Combined with careful tunneling, it was felt that this would be sufficient to maintain both safety and decorum. The paper discusses the construction planning, design provisions, grouting program, equipment and methods, problems and costs.

Media Info

  • Pagination: p. 296-310

Subject/Index Terms

Filing Info

  • Accession Number: 00152808
  • Record Type: Publication
  • Source Agency: Engineering Index
  • Report/Paper Numbers: Conf Paper
  • Files: TRIS
  • Created Date: May 31 1981 12:00AM