The fast-tracked sewer rehabilitation evaluation and design included the trenchless rehabilitation of 57,000 linear feet of pipes, which varied in size from eight inches to 52 inches in diameter. Trenchless construction using a tunneling boring machine (TBM) was performed to install 2,350 linear feet of 36-inch sewer line in a 72-inch tunnel in hard rock through a commercial/residential neighborhood.
Construction challenges, which we resolved in collaboration with the city and the contractor, included adjusting the work method in order to preserve existing surface features, and adjusting access points along the 52-inch lining portion to improve quality and reduce conflicts.