City of Gig Harbor Wins State Wide Public Works Award
Gig Harbor, Wash. May 10, 2011 – The City of Gig Harbor was awarded this week the prestigious Municipal Excellence Award from the Association of Washington Cities. The award is presented to the city’s Engineering and Public Works Departments for the expansion improvements at the SR 16/Burnham Drive NW Roundabout.
The project was chosen over all other public works projects submitted in the State of Washington.
Back in early 2003, the city identified that improvements to an existing interchange and its adjacent roadways were needed to accommodate a new community hospital whose aim was to serve the health care needs of residents of Gig Harbor, Key Peninsula, and south Kitsap County. The project included raising a periodically flooded roadway arterial and modifying two roundabouts at the interchange ramp ends to meet the goal of increasing the traffic-carrying capacity of the system.
A multi-stage solution was found that would achieve the goal of improving the transportation system to allow future development in the North Gig Harbor area, including for the new St. Anthony’s Hospital. The coordinated planning and engineering solution with a heavy emphasis from the Gig Harbor City Engineer included the following:
• A Comprehensive Plan Amendment modification of the City’s Level of Service (LOS) standards revising the acceptable LOS from a D to an E;
• Restriping and incorporating the existing Burnham Drive NW Bridge over SR-16;
• Reconfiguring the six-legged Burnham/Borgen Boulevard westbound Ramp Terminal roundabout to accommodate widened and reconfigured roadway alignments;
• Adding a right-turn slip lane from the westbound SR-16 off-Ramp to Burnham Drive southbound;
• Adding a right-turn slip lane from Canterwood Blvd. NW to the westbound SR-16 on-ramp;
• Widening the SR-16 westbound off-Ramp to provide approximately 400 linear feet of additional lane storage in order to keep vehicles from queuing from the SR-16 mainline;
• Realigning the SR-16 westbound on-ramp to accommodate both the reconfigured exit from the Burnham/Borgen Boulevard roundabout and the new Canterwood Blvd. NW right-turn slip lane;
• Widening Canterwood Blvd. NW for approximately 1,500 feet to accommodate increased vehicular traffic to and from the hospital, provide on-street bicycle lanes, and allow pedestrian travel via a new sidewalk under new illumination for the new corridor.
The constructed improvements provided an improved regional public access serving Gig Harbor’s largest retail and commercial center as well as the new hospital with an improved local access.
The most challenging components of the construction project consisted of the following items:
Challenging Wall Foundations in Tight Work Spaces - The geotechnical engineering work for the project involved evaluation and design of seven new retaining walls associated with project interchange improvements. At the expanded westbound ramp terminus roundabout, fill walls up to 26-ft.-tall were required to be constructed over potentially liquefiable and compressible soils, and immediately adjacent to sensitive wetland and stream areas. Through rigorous geotechnical engineering analyses as requested by the City Engineer, the geotechnical engineer, HWA GeoSciences (HWA), determined that treating the liquefiable/ compressible subgrade soil in place, using displacement rammed aggregate piers (D-RAP), would allow for conventional mechanically stabilized earth (MSE) walls to be constructed. HWA’s innovative approach, compared to more conventional soldier pile and tieback wall construction, ultimately saved the City of Gig Harbor more than $1M in construction costs.
Project Environmental Benefits
The transportation improvements themselves resulted in several other environmental mitigation improvements including the creation of new wetland areas, installation of a new fish passable box culvert to a location that had previously been a barrier to fish, and the daylighting of the main stem of McCormick Creek by removing entirely another fish-blocking culvert and installing a new fish passable concrete box culvert (12’ x 6’ x 80’) under Canterwood Blvd. NW.
Project Financial Cost Summary
The original combined project estimated costs for engineering, permitting, and construction costs for Phase One and Two approached $16,000,000. However, the actual ending costs were substantially lower by approximately $1,285,000 as shown on the attached Cost Summary Sheet.
The predominant reasons for this most successful project can be attributable to the following project components:
• Concise and clear Design and Engineering Bid Documents,
• Considerable upfront Geotechnical exploratory work and documentation,
• A partnered and effective working relationship between the Washington State Department of Transportation who in conjunction with the City Engineering staff worked side by side to work through many tough field construction challenges,
• A dedicated and experienced construction Contractor, who in conjunction with the City and the State, partnered together to achieve project completion within the allocated budget.
In conclusion, the success of this project is an example of many entities and individuals working together towards the common goal of completing a project within the allocated budget and resources available with a cost conscious approach, and fostering a partnered team approach.
The City thanks St. Anthony Hospital for funding the majority of the project. In 2007, a $5million dollar state CERB grant for this project was also secured by the City staff in conjunction with State Legislators.
For additional information regarding the project or the award please contact City of Gig Harbor City Engineer Steve Misiurak, P.E. at (253) 853-7626 or email@example.com
Learn more about Gig Harbor at www.cityofgigharbor.net