Construction on I-5 through Tacoma hits midway point

Cue up the Bon Jovi, Interstate 5 Tacoma commuters, and sing along: “Whoa-o, we’re halfway there ...”

That’s right. The seemingly interminable pair of construction projects near the Tacoma Dome are close to the midway point, and state transportation officials say they remain on schedule and within budget. Work is expected to wrap up by early 2018.

Here’s an update:

 

South M Street to Portland Avenue project

Price of construction: About $127 million, with an $11 million contingency.

Goal: Widen I-5 to install capacity for new carpool lanes and replace the aging road surface.

Accomplished:

▪ A new retaining wall has been built along most of the northbound and southbound lanes between South Yakima and Pacific avenues.

▪ New drainage ponds and a new “biofiltration” swale near McKinley Park have been completed.

▪ Piers and girders have been installed for new northbound bridge over Interstate 705. Crews are currently working to complete the bridge deck.

Left to be done:

▪ Complete the replacement of Pacific Avenue overpass (five of six piers are up already), a job probably finished this spring.

▪ Demolish and replace the McKinley Way overpass.

▪ Resurface the general-purpose lanes.

View from the ground: Longtime Transportation Department field engineer Troy Watts last week called the job one of the most complicated he’s been involved with.

Space is tight, traffic is heavy (more than 190,000 cars per day on average) and the construction schedule aggressive, Watts said.

“It’s a challenge,” he said.

Most things have gone smoothly, aside from a few excavation troubles, according to Transportation Department spokeswoman Claudia Bingham Baker.

“The cost of the contract has increased due to unanticipated conditions related to excavation of soil from the site, but we are still within the budgeted amount,” Bingham Baker said.

What to expect next: A three-week closure of the Pacific Avenue on-ramp to southbound I-5 is scheduled for late February. Other short-term ramp closures and lane shifts also are anticipated.

Portland Avenue to Port of Tacoma Road project

Price of construction: About $183 million with a $15.5 million contingency .

Goal: Build a new northbound I-5 bridge over the Puyallup River. The bridge will carry northbound general-purpose lanes and have capacity for a northbound carpool lane.

Accomplished:

▪ Soil stabilization improvements, including injecting grout, stone and cement into about 1,850 columns, are finished.

▪ Thirty-three of 46 bridge columns are completed.

▪ Nine of 15 crossbeams are installed.

Left to be done:

▪ Complete a new ramp from northbound I-5 to northbound state Route 167.

▪ Set girders on new bridge (probably this summer) and lay down road surface.

▪ Finish the work necessary to tie the bridge into existing northbound lanes on north side of river.

View from the ground: Building stuff across rivers is a tricky proposition, according to Transportation Department project manager Neal Uhlmeyer.

Crews had to build temporary trestles in the river to move their equipment around and work on the two piers in the water.

Environmental regulations also are a challenge.

“Even the mud is managed,” said Uhlmeyer, who pointed out that water that accumulates on the work site must be treated before being discharged.

What to expect next: “Over the next few months, motorists will see lane shifts on northbound I-5,” Bingham Baker said.

“We need to shift the northbound I-5 traffic toward the median on the north side of the Puyallup River to make enough room to construct the embankments for the new northbound I-5 bridge.”

What will happen to the existing northbound I-5 bridge over the Puyallup has not been determined, Bingham Baker said.

This story was originally published February 13, 2016 at 11:55 AM with the headline "Construction on I-5 through Tacoma hits midway point."