SMALL TUNNEL, BIG SOLUTION-THE PEARL RIVER CSO STORAGE AND CONVEYANCE TUNNEL PROJECT: TEAMWORK, CHALLENGES, AND LESSONS LEARNED

摘要

The City of Lafayette, Indiana, is located on the Wabash River in the central portionrnof the state. It is relatively small compared to most typical cities that incorporate tunnelsrninto their combined sewer overflow (CSO) control solutions. This small size meansrnless CSO flow resulting in an approximately 3-m-diameter (10-ft), 610-m-long (2,000-ft)rntunnel, which is relatively short and has a relatively small diameter compared to manyrnCSO tunnels. Nevertheless, the project was a large one from the owner’s perspective.rnThe urban setting and relative size and length of the tunnel, combined with highlyrnvariable ground conditions and shallow cover, resulted in several planning and designrnchallenges and led to some novel applications of tried and true tunneling methodsrnby the contractor, including use of compressed air and a built-up steel segment liner.rnOne of the keys to the project’s success was the teamwork and collaboration amongrnthe owner, the designer, and the contractor through the various stages of the project.rnThis paper describes the planning, design, and construction of this successful projectrnalong with several lessons learned along the way from the designer’s, contractor’s andrnowner’s perspectives.