New Irvington Tunnel Meets the Challenges

摘要

The New Irvington Tunnel, located in Alameda County, California, is a key component of SanrnFrancisco’s Water System Improvement Program. Mining of the 3.5-mile tunnel started in March 2011 and wasrncompleted in October 2013. Installation of the final lining is projected for completion in Summer 2014 and therntunnel commissioning for service is planned in Fall 2014. This paper will describe some of the key challengesrnencountered during the project construction phase and how they were successfully addressed and managed byrnthe project team. Some of the most significant challenges included a scarcity of experienced tunnel labor forrnconventional mining; very heavy groundwater inflows; difficult tunnel excavation including squeezing groundrnconditions; and gassy tunneling conditions which led to reclassification by CalOSHA during construction.