Port of Alaska, Replacing Corroded Docks with 75-Year Terminals

The Don Young Port of Alaska in Anchorage is running the Port of Alaska Modernization Program (PAMP) to replace its aging docks. The original terminals were built between the late 1950s and 1970s (Port of Alaska, n.d.a). Their foundations are corroded and have begun to split apart. Steel sleeves were fitted to keep them working, but these have also nearly reached their design life (Port of Alaska, n.d.a). The port states that the existing terminals suffer severe damage to their foundation piles from corrosion, berthing and seismic forces (Port of Alaska, n.d.c). The program aims to replace the docks before they fail and to improve resilience to extreme earthquakes and the harsh marine environment of Cook Inlet (Port of Alaska, n.d.d).

Approach

Long design life. Each replacement terminal is designed to last 75 years (a design objective, not a measured service life) (Port of Alaska, n.d.a).

Current seismic standards. New terminals follow the latest seismic design standards (Port of Alaska, n.d.a). The new cargo terminals will be built 140 feet seaward of the existing structure to reduce sedimentation impact, improve berthing safety and allow continued operations during construction (Port of Alaska, n.d.b).

Stabilizing the ground first. Under North Extension Stabilization Step 1, deep soil mixing was used to strengthen the soil. Crews removed a sheet pile wall and excavated about 1.1 million cubic yards of material. This created a new shoreline alignment for safer berthing at the cargo terminals (Port of Alaska, n.d.b).

Phased replacement. The port is replacing terminals one at a time. The Petroleum and Cement Terminal came first, followed by shoreline stabilization and the first new cargo terminal. Remaining old cargo terminals are to be demolished at the end of the program (Port of Alaska, n.d.b).

Testing before design. An early Test Pile Program included a geotechnical investigation and installation of ten 48-inch indicator pipe piles. It validated design assumptions on pile capacity and drivability (Port of Alaska, 2016).

Results

The Petroleum and Cement Terminal was completed in 2022 (Port of Alaska, n.d.a). It is supported by 123 precast concrete panels and 71 permanent piles. The port states it can survive ground shaking more than three times higher than the levels that occurred in Anchorage during the 1964 Good Friday Earthquake (Port of Alaska, n.d.c). North Extension Stabilization Step 1 was completed in 2025. Cargo Terminal 1 is under construction; the April 2025 program schedule targets project completion on 29 December 2029 (Port of Alaska, 2025).