Summary

Proceedings of session on tunneling at the ASCE Convention, held in Detroit, Michigan, October 22, 1985. Sponsored by the Construction Division of ASCE.

This collection contains four papers describing tunneling projects of varying diameters, design criteria, ground conditions, and construction techniques undertaken at locations in the United States. The unique method of multiple drift construction of the Mount Baker Ridge Tunnel in Seattle, Washington, presented a challenge to the contractor never before undertaken. The Flint, Michigan, sewer tunnel constructed over a period of three years was bored through soil conditions that varied from rock to running ground and utilized, by necessity, two different types of tunnel boring machines. Large diameter, continuous, soft ground, and hard rock tunnel boring machines were used for the construction of the Greenbelt Tunnels in Washington, D.C., and the deep tunnel TARP Project in Chicago, Illinois. The presentation and favorable acceptance of an extensive Value Engineering Change Proposal in Washington, D.C., and the new generation of tunnel boring machines in Chicago present a study in sound construction management and organization. Throughout these papers, authors describe the experience and construction approach taken by several different contractors for the successful completion of these varied and considerably difficult underground projects.