A massive construction project at the bustling Port of Tacoma calls on precast concrete for speed of installation.
By Leslie Lichtenberg
The Port of Tacoma, located on Washington’s Puget Sound, is a busy hub of shipping terminal activity, as well as home to warehousing, distribution and manufacturing. In 2002, approximately 1.47 million containers crossed the Port’s terminals, thus contributing to its nickname, the Gateway Port.
That same year, the 2,400-acre Port embarked on a $341 million Capital Improvement Plan, the largest construction project in the Port’s 86-year history, which includes the widening of the nearly three-mile-long Blair Waterway and the redevelopment of the Pierce County Terminal. The latter component of the project, begun in November 2003, involved transforming the Pierce County Terminal into the largest single container terminal north of Los Angeles. A wide range of precast concrete components proved to be a quick and easy installation for the massive project.
The impetus for the terminal redevelopment was an agreement between the Port of Tacoma and the Taiwan-based Evergreen Marine Corp., a global carrier that had long occupied the Port’s Terminal 4, a 75-acre site used for breakbulk, auto, heavy lift and other specialty cargoes. Evergreen’s steady growth and plans for expansion necessitated a move from Terminal 4 to the Pierce County Terminal. The end result would be a new “megaterminal” for Evergreen at the head of the Blair Waterway that would, upon completion of its second and final phase of development, encompass 237 acres.
ICON Materials of Kent, Wash., was no stranger to the Port of Tacoma when called in to manage construction of the new $46.2 million container terminal. “ICON had previously built a parking lot and rail depot for Evergreen at Terminal 4,” said ICON’s Bruce Harjehausen, noting that much of the activity at that site, dedicated for auto storage, would ultimately be relocated to a new auto facility at the Pierce County Terminal.
As the centerpiece of the Port’s five-year capital development program, the Evergreen terminal project was a high-profile undertaking that would, at its completion, include container and intermodal yards, utilities relocation, waterway widening, and improvements to adjacent streets. The redevelopment project during the first phase, encompassing 171 acres, involved the use of several types of precast concrete products, including railroad crossing panels, railroad ties, electrical vaults, oil/water separator vaults and manholes. The magnitude of the project was not lost on precast manufacturer Utility Vault of Auburn, Wash., which was responsible for producing the precast railroad grade crossings, electrical vaults, panel vaults and oil/water separators.
“More than 800 precast pieces were involved in this project,” explained Tom Weist, Utility Vault’s engineering manager. “Typically, a job of this nature involves between 50 and 100 units.”
Approximately 3,000 lineal feet of concrete railroad crossing panels were installed at the terminal’s new dockside intermodal rail facility. The Port’s objective, to create an infrastructure that would move containers from ship to rail or truck quickly and efficiently, relied on a high-capacity on-dock intermodal system to support the movement of cargo through the terminal. When forming the full-depth precast concrete railroad crossings, Utility Vault utilized a self-consolidating concrete mix with a 26-inch to 27-inch spread.
“This is a very flowable mix that is measured with a spread instead of a slump,” explained Weist. “It allows the concrete to flow into the form and to self-level on its own.”
Considered a very “high-end” mix, self-consolidating concrete, although perhaps more expensive than other products, will create a much greater return on the other end, according to Weist. Two reasons are efficiency and ease of installation, facilitated by the use of state-of-the-art precast concrete modular units that are set in place on a prepared subgrade.
The end result is a smooth, self-supporting slab system with no vertical or lateral movement. Other advantages of the modular system include strength, resilience and the elimination of the need for railroad crossing ties, which can settle or deteriorate.
“The Port made the decision at bid time to use precast railroad crossing panels over other materials because the former provided more flexibility. Should they become damaged at a later time, the precast panels can be easily removed and replaced,” said Harjehausen.
“When you look at total life-cycle cost, precast concrete is clearly the more cost-effective way to go,” said Frank Davidson, lead project engineer for the Pierce County Terminal.
The railroad crossing panels took approximately four and a half months to produce, according to Weist. An assembly line crew responsible for pouring the concrete, disassembling the forms, removing the product, cleaning the forms and preparing the precast units for transport to the site facilitated a smooth transition from factory to job site and helped keep the project on track.
“In terms of speed of installation, precast is the clear choice,” said Weist. “Contractors working on a job of this size and scale want to have the ability to put the product in as quickly as possible.”
Approximately 300 precast concrete electrical vaults as well as several oil/water separator vaults were installed at the new container terminal as well. Utility Vault poured vaults of various sizes, ranging from 2 by 3 by 3 feet to 8 by 16 by 8 feet. Many of the larger vaults were created using a panelized system, which allows each vault to be delivered in panels and erected on the job site. Although 100 percent customized, these panel vaults can be assembled and installed in less than two hours.
“When you consider the time it takes to prepare a base, set up forms and pour the base, cure, form and pour walls, strip walls, form up a roof and backfill the vault, you’re looking at several weeks with a poured-in-place product,” explained Weist. In contrast, precast vaults – even very large ones like those used in this project – can be prepared and installed in half a day, he said.
“For container handling requirements, the industry standard really necessitates the use of precast concrete vaults,” said Davidson. At the terminal, where containerized cargo includes everything from auto parts and machinery components to frozen meat and seafood, the wheel loads are very heavy.
At a large terminal facility of this scale, environmental concerns are also paramount. The Port’s decision to use precast concrete oil/water separator vaults stemmed from the need to offer environmental protection from surface water pollution. Utility Vault provided a precision-formed, high-quality reinforced concrete retention structure that would virtually eliminate trace oil from storm and wash-down water.
When completed this fall, the 171-acre Pierce County Terminal will have an annual capacity of more than 480,000 container lifts and an intermodal yard with the capacity of loading and unloading 72 intermodal rail cars, each 325 feet long. Phase 2 will expand the terminal to 237 acres with a 108-rail intermodal yard.
Construction on the ultrabusy shipping hub calls for products that are durable, dependable and easily installed. Precast concrete is answering that call.
Project Name: Pierce County Terminal Container Yard
Owner: Port of Tacoma, Wash.
Contractor: ICON Materials, Kent, Wash.
Precast Manufacturer: Utility Vault, Auburn, Wash.*
* Utility Vault is a certified plant under NPCA’s Quality Assurance/Plant Certification Program.