Under a taxiway at Juneau International Airport, an 8-ft. aluminum structural plate was severely corroded. The threat of collapse meant an immediate fix was needed. There are few reline systems that can rehabilitate structures this big and carry aircraft loads. The choice solution was an 84-in. diameter CORLIX® Aluminum Pipe from Contech. This was selected for its fast lead time, structural capacity and ability to resist corrosion in salt water.
The quick fix wasn’t simple, though. Jordan Creek is a drainage channel to the ocean from Juneau, Alaska. Since Juneau averages 58 inches of annual rainfall, multiple plans were in place to reroute the water and possibly divert through the reline process if peaks were reached. Compounding the physical site challenges, the host culvert initially was filled to the spring-line with gravel and stones.
Three 40-ft. pipe lengths minimized joints and seepage. The 120-ft. reline section was at the center of a 500-ft. stretch, so bulkheads had to be formed within the culvert. The initial plan called for a three-lift, three-day grout pour. At high tide the ground water levels and pressures increased above the grout pressures, causing the grouting procedure to halt on day two. A fourth day was needed to finish the grouting procedure due to site considerations.
An important feature to any reline project is experience and expertise. Stephl Engineering and subcontractor Mobile Concrete & Grout provided this experience and expertise, which was imperative with the changing site conditions and challenges of this reline project. Sliplining is an excellent solution to extend structure life. In the short-term it is cost-effective and in the long term up to an additional 100 years of service life can be gained.