TUKWILA – The State Route 99/International Boulevard on-ramp to eastbound SR 518 in Tukwila has reopened following emergency repairs to a culvert beneath the highway.
All lanes on the Airport Expressway on-ramp to eastbound SR 518 have also reopened.
The SR 99 on-ramp to eastbound SR 518 closed in late June due to a failure in the 42-inch-wide metal culvert that carries Gilliam Creek beneath both directions of SR 518. The failure weakened sections of roadway along the SR 99 and Airport Expressway on-ramps to eastbound SR 518.
Contractor crews working for the Washington State Department of Transportation installed a specialized lining made from layers of polyester felt inside roughly 265 feet of the culvert. With the help of pressurized air and heat, the liner conformed to the shape of the pipe to repair and reinforce the culvert.
“These repairs will seal the failed section of the culvert and protect against further erosion,” said WSDOT Project Engineer Thomas La Bolle. “We want to thank the public for their patience while we worked to identify the failure and develop what we expect to be a long-term repair.”
Crews also restored damaged sections of roadway on the SR 99 on-ramp to eastbound SR 518 and repaved these areas. Landscaping will continue within the work zone for the next week but will not require additional lane closures.