Franklin Pacific provided a full service concrete package for the seismic retrofit of the Service Tunnel at Sea-Tac Airport in 2018 and 2019. Our scope included constructing new concrete foundations and shear walls inside of the existing tunnel structure, overhead shotcrete rehabilitation of the existing tunnel lid, traffic barriers, and pedestrian sidewalks ramps, and bus stops. As this tunnel provides for all of the service activities and access to the airport it could not be closed to service related vehicles and traffic. As such Franklin Pacific performed the work in close proximity to this vehicle traffic and during off hours so as to minimize disruptions to airport operations.