Geologists study river bottom, for Sellwood Bridge
Efforts on several fronts are slowly-but-surely moving forward the Sellwood Bridge reconstruction project.
The most visible work on the project recently was featured on the front page of the August BEE: The huge floating drilling rig, and land-based driller on the east bank, which operated almost every workday during July and August.
Instead of drilling for oil or natural gas, though, these rigs were drilling for rock.
The rock-core samples which these projects revealed are critical to the success of the project, explained Ben Hoffman, P.E., with CH2M HILL Geotechnical Engineering.
'The drilled shaft foundations proposed for the new bridge will be founded in the basalt bedrock,' Hoffman noted. 'This is why it was sampled.'
They found that for which they were looking, Hoffman told THE BEE. 'It consists of the bedrock formation present below the Willamette River. The bedrock is called 'Basalt of Waverly Heights'.'
This basalt is located at depths of up to 150 feet below the bottom of the river.
Each sample of basalt which the engineers study are in five-foot-long rock core samples - all taken from a continuous sample that runs from the top of the basalt layer down to the bottom of the borehole. 'It's typically 50 to 60 feet below the top of the basalt layer,' Hoffman told us. He allowed us to view a representative sample of these cores.
During the first two weeks of September, crews will drill to determine the rock composition of the hillside west slope above Highway 43, just north of the Sellwood Bridge, and across from the former Staff Jennings location.
Citizens committee considers bridge options
The Sellwood Bridge Citizens Advisory Committee (CAC) will met again on August 22 at SMILE Station in Sellwood.
Committee members and visiting guests learned that the total cost for the bridge has been reduced from $290 million to $265 million. 'This is due, primarily to alterations in bridge details, and lower than estimated right-of-way acquisition costs,' explained Multnomah County's project spokesman, Mike Pullen. 'Also, during the planning phase, we spent less money than budgeted.'
Nevertheless, the project is still $20 million short on funding. 'We're asking the CAC, and staff, to look for project items we can delay into a 'second phase' of construction. Our goal is to submit a federal grant application in October to the Federal Transit Administration.'
After introducing new committee members, Multnomah County Commissioner Deborah Kafoury commended, 'I truly don't think that each of you are thanked enough, for the hard work you've done; you've gone above and beyond. What you're doing is extremely important; we need your input.'
During the public comment section of the meeting, CAC members first heard from Ellen Beatty, who advocated for continued efforts to make S.E. Tacoma Street, especially at the SE 13th Avenue intersection, a safer crossing. This is officially well beyond the east end of the project, but PDOT was already replacing the old signal lights at that intersection with improved models as August ended.
Committee members next paid rapt attention to possibly the youngest person to give testimony at a CAC meeting, Ellen Beatty's daughter, Claire. 'We want the bridge to be safe, so someday, when I grow up, I'd be able to go over it without my mom sometime. And, I feel scared when we go across [S.E. Tacoma Street]. The cars are really big, and they can go really fast.'
Claudine Moreno testified she's advocating for options that include safety features, lighting, and a gateway treatment that reminds eastbound drivers on the new bridge that they are about to enter a neighborhood.
Bradley Heintz, a Sellwood resident, echoed Moreno's sentiments, adding that S.E. Tacoma St. is metaphorically an intersection where those passing through - and those who reside in Sellwood - meet, and not always in a good way. 'Either this project will move in the direction of bringing the community together, or dividing it up. That's my fear.'
SMILE Board member Eric Miller checked to make sure CAC members had a copy of the Board's letter regarding the gateway and neighborhood entry transition treatments, and other public safety issues.
Commissioner Kafoury said that, in her letter of response, she had observed that, 'Safety has always been the main reason to replace the deteriorating Sellwood Bridge. With SMILE support and encouragement, we will be creating a two-lane bridge, using an aesthetically-pleasing design.'
Retired physician Rich Rubin again testified regarding his wife's being struck by a car in the crosswalk at S.E. 13th and Tacoma some months ago. 'She had a miraculous recovery, but it was a very scary situation. Since that time, I've heard a lot of near-misses and accidents at the intersection.' He added, 'I implore you, consider safety features.'
'Virtual open house' results vetted
Kalin Schmoldt, a consultant from JLA Public Involvement, working with CAC facilitator Alex Cousins, spoke about the preliminary results of the information gathered from the Sellwood Bridge 'Virtual Open House' Internet-based survey of bridge amenity and safety options.
'The survey covered topics like structural element surface treatments, structural lighting, supplemental path waiting, multi-use Path surface treatment, pylons and gateways, Belvederes, fencing and benches,' Schmoldt began.
As on comment cards at real-life public open houses, Schmoldt evaluated participation of Sellwood residents, cyclists, and other groups, to see whether any group was skewing the responses. 'The results are in line with what we've seen in past surveys,' he said.
Cyclist respondents provided 42 out of 204 completed surveys; many said they primarily use bicycles cross the bridge. Responses from cyclists closely paralleled the answers from all respondents, although cyclists expressed greater support for path lighting and path surface treatments.
Of the completed comment forms, 82 of the 204 responses came from ZIP Code 97202, Schmoldt reported. 'These respondents were less likely to pick a specific feature as unimportant or unnecessary. Otherwise, these responses paralleled the plurality for other questions for all respondents.'
'Overall, responses are consistent from what we've seen before,' Schmoldt confirmed to THE BEE after his presentation. 'Those who completed surveys are a fraction of the estimated 2,700 people who visited the site virtual open house. We didn't see anything out of the ordinary in our preliminary evaluation.'
For those wishing to see a comprehensive report on that survey, Schmoldt said the results will soon be posted on the project's Internet website: www.SellwoodBridge.org .