US COAST GUARD, PIER 36 DREDGING PROJECT
SEATTLE, WA

In 2003/2004, the Department of Homeland Security’s U.S. Coast Guard Division contracted ACC to perform a $4 million Navigation Improvement Project for the Coast Guard’s Support Command Facility on the Seattle waterfront. The facility serves as a homeport to ice breakers, border patrol vessels and homeland security vessels. Originally built in the 1920s, it was the focus of a program to update, widen and deepen its waterway and moorage capacity. As part of this program, ACC constructed a 440-foot concrete pier including a 600-foot upland sheet pile wall and a 440-foot underwater bulkhead.

The project also served as a pilot program for introducing Stone Columns in the Puget Sound area as a means of attenuating earthquake damage to the marine-based infrastructure. ACC partnered with AGRA Foundations Ltd. of Vancouver, B.C. to install 153 underwater stone columns designed to dampen the effects of earthquake vibration by relieving pore pressure and providing horizontal soil resistance via displacement.

Dredging activities involved removing over 51,000 tons of bottom sediments including over 36,000 tons contaminated with heavy metals, PCB’s and petroleum products. The latter was placed on flat deck barges, dewatered and then trans-loaded to railcars for upland disposal.

PACIFIC SOUND RESOURCES (PSR) SUPERFUND SITE PROJECT
SEATTLE, WA

The Marine Sediment Unit encompassed approximately 58 acres of Elliot Bay along approximately 2,000 feet of shoreline. Contaminated sediments were dredged from the Crowley Marine Services Area to maintain current navigational depths.

Control of the bucket for dredging and the skiff box for placement was done using the WINOPS program that tracks the x, y and z of the bucket or box at all times, accounting for variations caused by bottom elevation and tide activity. The work also included placement of capping materials within the Marine Sediment Unit (MSU) for remediation of the Pacific Sound Resources (PSR) Superfund Site. For engineering purposes the MSU cap area was subdivided into remediation areas according to specific site conditions and operational conditions that required different cap designs, cap materials specifications or construction methods.

RIVER BANK STABILIZATION
STOCKTON, CA

This project was performed for The Groupe Co., a private development contractor based in Stockton, California. The project involved furnishing and placing approximately 52,000 tons of rock protection onto 2,800 feet of levee on the Sacramento River in West Sacramento. In order to satisfy permit requirements, the job was fast-tracked and completed in just two months. The rock was transported from two quarries in the Sierra foothills, loaded onto material barges and towed to the jobsite upriver using large capacity tugs working around the clock. The material was placed on site using a 200-ton lattice boom crane mounted on a barge and rigged with a skip box that allowed for eight tons of material to be placed in each offload cycle.

WHITTIER FERRY TERMINAL PROJECT
WHITTIER, AK

In order to accommodate larger vessels, The Whittier Ferry Terminal Modifications Project required ACC to remove a 5-dolphin and 40-pile fender system and replace it with a new 10-dolphin fender system.

ACC installed over 4,000 lineal feet of 30” galvanized steel piling and several hundred lineal feet of smaller diameter piling. To expedite the construction process, the fender panels were prefabricated in Seattle and shipped to the site via a barge.

It was realized that the new facility, designed for larger vessels and heavier traffic, required better control of the transfer span than the original design indicated. ACC modified the existing transfer span’s syncrolift system to increase the range of motion for the main span. Additionally, a hydraulically actuated apron was mounted to the end of the transfer span.