A Volvo 35-ton (31.7 t) articulated truck hauls away dirt from a job site.
It used to be that drivers traveling between Tacoma or Gig Harbor and Port Orchard along Washington’s SR 16 had to be especially alert as they approached the community of Burley. The intersection of SR 16 and Burley Olalla Road was this section of highway’s last remaining at-grade intersection, and as such, had a high incidence of severe accidents.
So when Tacoma-based contractor Ceccanti Inc. began construction on a grade-separated tight-diamond interchange at SR 16 and Burley Olalla Road, local emergency service workers and the public breathed a collective sigh of relief.
Thirteen months later, the $16.3-million contract is 80 to 85 percent complete. Final grading is under way and paving is scheduled for the second week of September.
The bulk of the project consisted of building two concrete box girder bridges to carry SR 16 traffic over Burley Olalla Road. The northern and southern abutment walls are continuous between the two bridge structures, to allow for the future addition of a HOV lane in each direction, if necessary.
“All we’ll have to do is bring in box girders and we’ll be good to go,” said Washington State Department of Transportation Project Engineer Brenden Clarke.
The decision to move the high-traffic highway instead of the road seemed counterintuitive to the public, according to Clarke, but it made sense from an engineering standpoint because of Burley Olalla Road’s steep grade.
“In addition, the soil on the downhill side is very poor and soggy, so it would have been very difficult to have built a structure — the footing would have had to be very deep to overcome the poor soil,” explained Clarke.
A structure carrying Burley Olalla Road over SR 16 would have been much longer than the final span of less than 150 ft. (45.7 m).
“It was much cheaper to build up dirt on either side of the bridge and build over Burley Olalla,” Clarke said.
According to the original plan, the interchange improvements would have taken two years to complete. However, WSDOT engineers put their heads together with Ceccanti’s staff and came up with an alternative plan that shaved nearly a year off the schedule, by using the new on- and off-ramps as detours, instead of building a detour road around the entire project, per the original plan.
Ceccanti’s project manager Jon Vander Griend said: “The job as designed required massive temporary road construction that would have still been in place at this time. That would have meant the project couldn’t be completed until next summer. But they [WSDOT] came to us with some ideas and we came back to them with some proposals as to how we could do it.”
By eliminating the time that would have been spent building the detour road, Ceccanti was able to finish enough grading last summer that crews were able to work on the structures through the winter.
Particularly challenging were two weekend single lane closures, during which Ceccanti worked up to 24 hours a day to implement eastbound and westbound tie-ins for the SR 16 temporary alignments. The riskier of the two closures included tying into a 11-ft. (3.3 m) grade change.
“Ceccanti was willing to take the risk that they’d complete all that work in one weekend, and they did,” said Clarke.
A Volvo 35-ton (31.7 t) articulated truck was “a major help” on the job, said Vander Griend, “especially when we had, during that weekend shut down, to move a large amount of material quickly, with no road and no other way to move material other than those off-road trucks.” Another machine that was key to the project was a John Deere 850 excavator leased from Papé Machinery, which has seven locations in Washington.
Soil management presented another challenge because nearby Burley Creek is considered sensitive fish habitat.
“Last winter was the key to the job,” said Vander Griend. “To keep working without endangering the creek was our big goal, and a combined goal of the owner’s.”
One of the solutions that helped Ceccanti successfully meet environmental requirements was implemented per the suggestion of WSDOT’s Port Orchard office. That suggestion was to leave some trees near the edge of the job site, set with level-spreaders, to act as a natural bio-filter during construction. During winter rains, the site’s storm water run-off was pumped onto the forest floor so that no sediment-laden waters could contaminate the creek. The trees were later removed.
This kind of problem-solving and cooperation between owner and contractor was the rule on this project, rather than the exception. Vander Griend said: “[WSDOT’s Port Orchard office was] a real leader out there. They had ideas. They weren’t just looking to us to pull a magic show out there.” CEG