June 4, 2015

South Park Bridge, Seahurst Park both win ASCE awards

Photo courtesy of King County Department of Transportation [enlarge]

The new South Park Bridge restores a major link across the Duwamish River and is designed to withstand large earthquakes.

The American Society of Civil Engineers Seattle Section recognized five projects with awards for Local Outstanding Civil Engineering Achievement.

ASCE Seattle will present the awards at a ceremony that begins at 5:30 p.m. June 10 at Best Western Executive Inn in Seattle.

The awards recognize projects in several categories: geotechnical, structural, ports and waterways, water resources, transportation and development, small projects and non-construction studies.

Projects must have been done by a civil engineer who is a member of the Seattle Section; be located in King, Snohomish, Kitsap, Whatcom, Skagit, San Juan, Island, Clallam and Jefferson counties; be substantially completed in 2014; and be predominantly civil engineering-related work.

Here are the winners:

• South Park Bridge Replacement Project, structures category

HNTB Corp. designed the drawbridge and HDR, Inc. was the construction manager. King County owns the bridge.

The bridge was completed in 2014. It is designed to withstand large earthquakes, improve the environment, and provide safe crossing over the Duwamish River for pedestrians, cyclists, motorists and freight carriers.

The project includes creation of a pocket park/rain garden on the footprint of old bridge, which was closed because of safety concerns.

Salvaged features of the old bridge were built into the new one.

Photo by Hans Adomeit/Anchor QEA [enlarge]

Here is Seahurst Park’s shoreline following seawall removal, beach restoration and park improvements. The project restored 2,800 feet of Puget Sound shoreline.

• Seahurst Park Phase II Ecosystem Restoration Project, ports and waterways category

Anchor QEA was on the project team. The park is owned by the city of Burien.

The 154-acre park has over 4,000 linear feet of Puget Sound shoreline. In the early 1970s, most of the shoreline was armored with seawalls, gabions and riprap that became a safety hazard and degraded the beach and habitat.

In 1996, the park was transferred from King County to Burien, which partnered with the U.S. Army Corps of Engineers to restore the shoreline and recreational facilities. The final phase was completed in 2014 with restoration of the north shoreline.

That work included bulkhead removal, restoration of beach and riparian habitat and wetlands, creek daylighting, culvert installation, trail and walkway improvements, utility relocations, replacement of the parking area with pervious paving and bioretention facilities, and replacement of a fish ladder, and a picnic and play area.

Grants supplemented funding from the Corps.

• The Green River Filtration Facility, water resources category

The project team included MWH Americas, design engineer; Hoffman Construction Co., general contractor/construction manager; and agency involvement by the Washington State Department of Health. The city of Tacoma owns the project.

The facility added a barrier between the Green River and the tap for Tacoma Water's over 300,000 customers in Pierce and south King counties.

The former unfiltered system was built in 1913 and sent about 1,000 pounds of fine sediment into drinking water pipes daily.

Now coagulants are added to the raw water, which causes silt suspended in the water to clump into larger particles that settle out in the new plant. Remaining particles are screened out through filters containing anthracite coal and engineered sand.

The cleaner water will meet new public health regulations and improve water quality. The removed solids are dewatered and pushed through screw presses that further separate the dirt from the water.

• 25th Street Bike and Pedestrian Improvements, transportation and development category

The project team included Tuttle Engineering and Management, Osborn Consulting, GeoEngineers, Mariano & Associates Design, Northwest Environmental Consulting and Rubenkonig Planning and Landscape Architecture. The city of Bellingham owns the project.

The project evaluated issues along 25th Street and Douglas Avenue in south Bellingham.

Improvements were made to the corridor for pedestrian and bicycle safety, increased capacity and improved stormwater collection.

• Northshore Summit Park Design and Construction, small projects category

The project team included Osborn Consulting, The Watershed Co., and Northwest Environmental Consulting. The city of Kenmore owns the project.

Innovative engineering transformed 3.6 acres of underused, waterlogged open space into a multiuse park with picnic areas, playgrounds, trails, wetland, and forest. It opened in May 2014 as Kenmore's eighth city park.

Because the site is in a residential neighborhood the engineers needed to design the park to balance environmental and neighbor concerns, community wish lists and site constraints.

Significant drainage and grading improvements also were made.