?1.8M DOUBLE SHIELD TBM FOR MIXED GROUND SEWER TUNNELS IN CINCINNATI

摘要

A Robbins “Rockhead” ?1.8m double shield TBM is being used to excavate softrnshale and harder limestone in Cincinnati, Ohio. Seven tunnels will be excavated, withrnlengths ranging from 250 to 610 meters (816 to 2,014 LF), for a total of 2,875 metersrn(9,430 LF). These are relatively long tunnel drives for such a small-diameter excavation.rnPrimary support will be 100 mm (4 in WF) steel ring beams on 1.5 meter (5 ft) centers.rnThis paper will describe the special TBM, muck haulage, and launch shaft featuresrnwhich were carefully implemented to support rapid mobilization and excavation on thisrnsmall diameter project.