Project Two-Mile Bar Tunnel

The project included soil nail/shotcrete portal construction, mass surface excavation and haulage, tunnel construction using roadheaders, and installing diversion structures related to directing water into the tunnel away from the existing canal. The tunnel excavation was performed from both ends, one heading of which was performed completely under winter canal shutdown/outage periods. This portion was at the downstream portal and was terminated at 552’ leaving the remaining 5,397’ to be excavated from the upstream portal. Both excavations included ground support of shotcrete, rock bolts, and occasional steel sets. To complete the long stretch of tunnel from the upstream portal, Drill Tech installed a complex electrical distribution system with generators, high voltage transmission cables, and transformers to provide power to the heading for the roadheader. At the completion of tunnel construction, Drill Tech installed a final shotcrete liner and concrete invert for future irrigation water flows.