ABSTRACT
In Chaps. 16, 17 and 18, the applications were primarily either water shutoff or strengthening a formation. In tunnel and shaft grouting, generally both purposes must be served. In addition, tunnels and shafts (because of their greater depth below grade) often involve the use of much higher pressures than the projects detailed in the previous three chapters (except for mine waterproofing, which may also take place at substantial depths). Further, tunnels and shafts are often very large projects and (like large cutoff walls) are often preceded by extensive soil investigation. This permits prediction of possible water problems and the detailed preplanning of how those problems will be handled. The procedures used in grouting tunnels and shafts are much the same regardless of project site and can be illustrated by case histories of relatively small projects as well as large ones.
