November 12, 2004

Cooperation produced results for convention center

Jones

Ledingham

The Greater Tacoma Convention and Trade Center's large footprint, unique sloping lot and the fast-track schedule required close coordination between project partners and stakeholders.

The project also magically transformed the neighborhood into a streetscape that beckons with economic vitality and captures sweeping views of Tacoma.

A distinct appeal

Parametrix led the civil engineering design of the project. The design effort included topographical surveying, engineering design for demolition, erosion control, grading, streets, sidewalks, surface parking, stormwater treatment and conveyance, connections to city utilities, retaining walls and a water feature.

The city of Tacoma turned to a non-traditional design and building approach for the project — general contractor/construction manger — in which one company serves as both the general contractor and construction manager. The project's GC/CM, M.A. Mortenson Co., worked with the design team from the start of the schematic design, ensuring the design of each construction phase was within budget.

The process required the team to meet aggressive schedules for multiple bid packages. This approach required unique problem-solving and collaboration. The result was a user-friendly design for the building, streets and entrances. Creative features give the building its distinct appeal.

Slope design

Photo courtesy of Parametrix Sidewalks along the convention center’s steep slopes were built on grades designed to improve their accessibility to pedestrians.

One eye-catching element to the design is the water feature on the corner of South 15th and Commerce streets. Parametrix's structural engineering group provided the structural design for this element, which involved granite pavers floating on pre-cast beams with water jets at the corners of the pavers. The water is recirculated in the structure, providing the dancing movement of the water.

On 15th and Commerce, the civil design includes a decorative hardscape and landscape design, including multiple sets of stairs, walls, colored sidewalk and benches, planters, tree wells and a water feature.

Much of this area is on steep slopes that proved difficult to make usable. The features provide the building a stronger street presence and a good first impression to visitors.

Challenges, improvements

The convention center's sloping site and surrounding streets provided many other challenges to the civil design.

A key concern was street access and, given the grades of the pavement, meeting ADA requirements.

This was accomplished by designing the sidewalk to run at a separate grade from the street, in a location that worked best for pedestrians.

Another design goal was to create a user-friendly drop-off zone for pedestrians and buses in front of the convention center on Commerce, which also has the Link light-rail line running along it. The convention center will see hundreds of people come and go in a given day, and the key was to allow this to happen safely and easily without delaying traffic.

To prevent disruptions for the Tacoma Link, project partners worked closely with Sound Transit, which operates the light-rail line. Capitalizing on public transportation alternatives was another strategy to improve access to the convention center. A light-rail station is located at the corner of 15th and Commerce.

Updating the infrastructure

So, what do you do with stormwater runoff from a building with a roof the size of two football fields?

The project design allowed for an upgrade of current stormwater-handling capabilities, connecting the four 12-inch roof drains from the building. The stormwater from the site is being treated through conventional oil/water separators before the stormwater goes off site.

The convention center design improved several surrounding streets, including Commerce Street. If you're familiar with the area, you may remember that the South 17th Street and Commerce intersection was hard to navigate, with no definitive lanes for traffic.

The street will become a one-way road blanketed with a park-like setting including tree-lined sidewalks and lighting. Construction is under way. To accomplish these improvements, a trolley track, used in the early 1900s, had to be removed to allow for the proper paving of Commerce. This removal was no easy feat.

The trolley tracks and stormwater-handling facility were not the only outdated infrastructure that designers had to contend with.

Over the years, the city's brick roads were overlaid with asphalt. Today, this brick hinders efforts to install utilities and build quality roads. The design team worked closely with the city and the different utilities to ensure fiber optics, electricity, gas and water were incorporated into the street design. The product will last for many years.

Keys to success

Synergy and collaboration were keys to the success of the convention center project.

"The GC/CM method for project delivery provided the synergy and cooperation necessary to succeed on a challenging project with a fast-track schedule," said Dan McReynolds, project manager for Parametrix.

The convention center features several design components that are transparent to onlookers but were critical to engineers, architects, contractors and stakeholders in bringing the project to a successful completion.

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Justin Jones was the Tacoma convention center design engineer for Parametrix. Denise Ledingham is responsible for the firm's public relations.

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• Tacoma builds a not-so-conventional trade center
  
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