The Tunnel and Reservoir Plan for the Metropolitan Chicago area calls for tunnels with diameters in the range of 15 to 35 feet (4.57 to 10.67 meters). Jarva, Inc. of Solon, Ohio is currently manufacturing the large size tunneling machines that are required. Three rock tunnels which were forerunners of this plan have proven the successfulness of using the large tunneling machines, referred to as "moles", in the Chicago area. The machines advanced at the rate of 5 to 6 feet (1.5 to 1.8 meters) per hour. Alignment was accurately maintained with laser beam control. Costs were reduced below those for drill-and-blast methods by the time of construction of the third project. Other advantages of using the tunnel boring machines rather than drilling and blasting include elimination of objectionable surface vibrations, a tunnel free of rough surfaces, and a reduction in the need for rock bolts and anchors since rock beyond the tunnel perimeter remains intact. Also, in instances when the tunnel is in rock of sufficiently sound and durable quality, because the smooth wall is very efficient hydraulically, the tunnel may be left unlined effecting a considerable savings in cost.

  • Corporate Authors:

    Western Society of Engineers

    176 West Adams Street
    Chicago, IL  United States  60603
  • Publication Date: 1976-3

Media Info

  • Features: Figures;
  • Pagination: p. 4-7
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00131663
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Jun 5 1976 12:00AM