A CURED IN PLACE PIPE REHABILITATION PROJECT TURNED BYPASS PUMPING PROJECT

摘要

The Dublin San Ramon Services District (District) Dublin Trunk Rehabilitation Project rehabilitated approximately 8,000 linear feet of deteriorating 33-, 36-, 39-, and 42-inch reinforced concrete trunk sewer that conveys approximately 50 percent of the District's wastewater flows. The Dublin Trunk sewer is located within highly trafficked roads in residential and busy commercial areas in the cities of Dublin and Pleasanton, California. The trunk sewer also crosses a number of other jurisdictions, including the California Department of Transportation (Caltrans), Zone 7 Water Agency (Zone 7), East Bay Regional Parks District (EBRPD), the District's wastewater treatment plant, and a number of private commercial properties.To minimize public impact, the District selected steam-cured, cured-in-place pipe (CIPP) lining as the preferred rehabilitation method. That decision was the easy part; the real work was developing—and then continually revising—the bypass pumping plan that supported CIPP installation. The City of Dublin was far more concerned with the bypass setup and potential impacts on residents and businesses than the rehabilitation process. To shorten construction, the City allowed the contractor to install the CIPP lining 24 hours a day. Detailed engineering was needed to design bypass pump placement and undergrounding, mitigate impacts to traffic signals, negotiate work hours, and determine the best locations and methods for crossing a flood control channel and interstate highway. Many of these factors significantly impacted the project’s cost and time.This paper describes how trenchless technologies and creative bypass pumping can meet tight schedules, overcome accessibility constraints, comply with traffic control requirements, and address diverse stakeholder concerns to rehabilitate a critical trunk sewer.