Roads and Bridges

Seattle Tunnel

This $1 Billion project consists of 8,800 feet of bored tunnel to replace the existing Alaskan Way Viaduct. The Bored Tunnel will follow a large radius curve beginning just south of S. Washington Street, and then pass under Western Avenue to be parallel with First Avenue. The first 500 feet of the Project includes a depressed roadway that contains mainline SR 99 and southbound-off and northbound-on ramps. The roadway structure inside the Bored Tunnel will stack the

AKDOT Gustavus Causeway Replacement

This project consisted of a $21 million replacement of an existing timber approach and dock with new galvanized steel pipe pile structures for public transportation and freight.  Construction included a 1,300-foot, two-lane causeway connected to a 6,000-square-foot dock.  The dock incorporates a wave barrier with gap-faced timber pile fender systems.  The project also included a new pontoon-supported, tidally operated transfer bridge, platform, ramp

Westlake Pedestrian Bridge

This project consists of annual inspections every two years on a 130-foot long, cable-stayed suspension pedestrian bridge that spans Westlake Avenue North and has a central double-steel mast tower and a pile-supported concrete viewing platform.  The bridge, accessed by a 50-foot long, clear-span, steel-framed stairway, was precast and prestressed, and erected in segments.  The overpass provides arterial clearances of 22 feet and 21 feet for adjacent railr

Witte Road 248th Street Improvements

This project consisted of a roundabout intersection with two, 11-foot travel lanes, a median with bicycle lanes, curb, gutter, sidewalk and a pedestrian crosswalk on all four legs of the intersection. Other improvements included a storm drain system, lighting and signage.  We provided reinforced concrete inspection, testing of soils such as soil density, LA abrasion, sand equivalency, sieve analysis, soil moisture density relationship and organic impuriti

WSDOT SR 532 Corridor Improvements

This $50.4 million improvement project along State Route 532 addresses a variety of safety and congestion issues by building a wider bridge to replace the General Mark Clark bridge, adding turn lanes at numerous intersections and installing three truck-climbing lanes.  Inspections included soil compaction, aggregate base, reinforced concrete and welding.

Hood Canal Bridge Retrofit and Replacement

This $204 million project includes the replacement of the east half with a new floating section and repairs to the west half of this 1.5 mile-long bridge.  The rehabilitation also adds new approach sections and transition trusses on east and west ends, as well as road widening on the western half.  Services provided include consulting and construction support for new steel bridge, one of the first in the United States to incorporate large tubular fracture

SeaTac Offsite Roadway Improvements

This $8.7 million roadway project includes the relocation of utilities underground, widening of International Boulevard, a bridge over SR518 and new on/off-ramps. This project helps accommodate SeaTac’s new $419 million consolidated Rental Car Facility. Inspections include reinforced concrete and epoxy grouted and expansion anchors. We also provided testing of soils and asphalt.

Redmond Northeast 36th Street Bridge

The project consisted of a new $30 million, 480-foot long off-set lid overpass spanning State Route 520, connecting the east and west sides of the Microsoft campus. The overpass has one lane in each direction, a bicycle lane and pedestrian walkways. Inspections included soil density testing, concrete inspection and asphalt density testing.

WSDOT I405, I5 to SR169 Stage 2 Widening

This project consists of a new $83.6 million half-diamond interchange on I-405 east of the I-405/SR 167 interchange at SR 515 to improve access to downtown Renton and relieve traffic demand on the I-405 interchanges at SR 167 and SR 169.  Inspections included soils, concrete, welding, asphalt and electrical.