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Preliminary Feasibility Study for a Ground Modification System for Egress Tunnel Construction.

Wakefield DC; Curran JW; Foster EL
Will Be Available Through NTIS :85 pages
A preliminary systems concept and feasibility study of a ground modification system for egress through rubble has been made. The rubble environment has been postulated to include rock particles ranging in size from gravel to tens of feet in principal dimension. A system has been conceptualized that would store grout components at a safe (deep) level, transfer them to the heading, and inject them into the rubble ahead of the tunnel boring machine (tbm). Crushed muck from the tbm may be stowed in the larger cavities to reduce total grout requirements. Available grouts appear to have many of the properties needed for proper functioning rubble. The system employs a stinger, a steel tube 15 in. In diameter, which extends through the center of the cutterhead out to a maximum of 35 ft. It carries its own motor and tricone bit and other equipment needed for carrying out the grout injection process. Control of grout envelope position is sensed by geophysical instrumentation and controlled from a remote booth. The preliminary study indicates that the system is feasible, although more detailed studies are recommended. Research was done under contract j0133918 by UTD Corp. Copies of this report will not be available for purchase.
Publication Date
Document Type
CP; Final Contract Report;
Fiscal Year
Identifying No.
NIOSH Division
Source Name
Will Be Available Through NTIS
Performing Organization
Utd Corporation
Page last reviewed: November 12, 2021
Content source: National Institute for Occupational Safety and Health Education and Information Division