Pile driving underwater noise attenuation: port of anchorage modernization project adds to body of knowledge.

• Author: Anderson, Tasha
• Position: TRANSPORTATION

The 2015 Alaska Association of Harbormasters and Port Administrators Conference took place in October at the Hotel Captain Cook in Anchorage. One of the presentations on the second day of the conference was about the Port of Anchorage Modernization Project, given by Lon Elledge, Program Manager for the CH2M Project Management Consultant team. The project will include replacing petroleum terminals 1 and 2; replacing cargo terminals 1 and 2; improving the seismic resilience of the port; incorporating more modern technology; and enhancing operational efficiencies. Elledge stated that the estimated cost, "for everything," is an anticipated $485 million, with a timeline of nine years, five to six of which would be construction. According to the Projects website, some construction is anticipated in 2016.

Port of Anchorage Modernization

The Port of Anchorage's annual throughput averages 3.2 million to 3.5 million tons. For Southcentral, which holds the majority of Alaska's population, about 74 percent of incoming freight and upwards of 90 percent of imported refined petroleum is waterborne, Steve Ribuffo, Port of Anchorage director, reported at the conference.

The Port of Anchorage is a vital part of the state's transportation infrastructure, and while the project is expensive, it's also necessary. "The oldest terminals were built in the 1960s, and the newest container terminal is still forty years old; seismically, they're not current and suffer from severe corrosion," Elledge said. "We also want to add backup power for the cranes in case there's a power outage [so] during that time we can still handle cargo."

Several aspects of the project are being designed specifically with longevity in mind. For instance, the Port's container clearings currently in use are thirty-eight foot gauge; with the modernization, the Port plans to install "at least fifty-foot gauge cranes, which will give us a container range of fourteen containers across," Elledge said; however, plans allow for future installation of one-hundred-foot gauge cranes without having to rebuild the wharf. Plans also call for a composite pile design, which have a seventy-five-year life.

One of the earliest aspects of the project is looking at pile driving technology. At the time of the conference, the Port was in the process of receiving permitting for a test pile program. The goal of this program is to gather site-specific data about the effectiveness of underwater noise mitigation...