Design and Implementation of a Large-Diameter, Dual-Mode 'Crossover' TBM for the Akron Ohio Canal Interceptor Tunnel

摘要

The Ohio Canal Interceptor Tunnel (OCIT) Project involves construction of a conveyance and storage tunnel system to control combined sewer overflows for several regulators in the downtown Akron area.The 27-foot (9.26m) finished inside diameter tunnel, approximately 6,200 feet long (1,890m), will pass through ground conditions that consist of soft ground, mixed face soft ground over bedrock, and bedrock. Depth to the invert of the OCIT will range from about 40 to 180 feet (12-55m). A Robbins dual mode type "Crossover" (XRE) Rock/ EPB TBM, 09.26m bore in diameter, will be used to excavate the tunnel and install the precast segmental lining. Special design features will be implemented to overcome the changing geological conditions. The XRE TBM will feature characteristics of both Single Shield Hard Rock machines and EPBs for efficient excavation in mixed soils with rock, such as a flexible cutterhead design for proficient boring in both rock and soil conditions, adjustable main drive speed with an over-speed mode for operation in hard rock, and special screw conveyor wear protection measures. The paper will describe these design features, their manufacturing process and implementation in the field.