Case Study of Domestic Water Main Replacement Using Slip Lining at Seattle-Tacoma International Airport

摘要

Seattle-Tacoma International (Sea-Tac) Airport is one of the fastest growing major airports in North America. Approximately 9,400 airline and airport employees park at the North Employee Parking Lot, located 2 miles north of the airport. The parking lot includes 3 shelters, where employees wait for buses that shuttle them to and from the airport, and a guard shack. Each of these buildings has a restroom. Water to the restrooms is supplied by approximately 3,100 feet of 2-inch and 3-inch underground PVC pipe. A few years ago, water began seeping from underneath the parking lot, causing slippery conditions in the winter. This was originally thought to be due to groundwater, but the presence of residual chlorine indicated that a contributing source was potable water. Airport maintenance crews attempted spot repairs of the buried PVC pipe at different locations, but the seepage continued. It was finally decided to replace the pipe. Port construction crews retained a contractor who specialized in slip lining. Holes were dug at changes in direction, and DR 11 HDPE pipe was inserted through the existing pipe. Construction was completed in less than 2 months at a savings estimated at one-third the cost of open trench techniques.