The City of Sherwood broke ground on its bicycle and pedestrian crossing of Highway 99W in March 2024. Construction this year saw erection of three of the five concrete bents and most of the west approach retaining walls and embankment. Hidden in the onsite staging yard, the integrated preconstruction mockup previews the final design details. Offsite, millions of dollars worth of steel and railings were fabricated and prepared for quick assembly on site, with the main span arriving just before the new year (which I’ll document next year). Construction is scheduled to wrap up by fall of 2025.
Work begins on opposite sides of the roundabout, with formwork for concrete bent walls to the left and grading for the west approach to the right.Between the roundabout and Sherwood High School, earthwork begins for the creation of terraced embankments for the west approach ramp.Excavation and fill begin to shape the footprint of the curved gabion walls for the west approach.The construction of bents 3 and 4 offers a first glimpse at the future on-bridge experience, up in the trees with excellent views to Sherwood High School.The view atop bent 4 to the 99W/Sunset/Elwert intersection overlooks the heavy traffic that future bridge users will bypass.Looking north from bent 4 along the utility lines that will be raised and undergrounded to create a safe clearance from the bridge deck.Work continues on the west approach as the formwork is stripped to reveal the first concrete bent.The concrete bent walls feature a simple reveal pattern to break up the intentionally-monolithic massing when viewed more closely.The concrete bents were envisioned as simple, raw concrete (as inspired brutalism); however, they will be finished smooth and painted per ODOT standards for ease of maintenance.Bent 3, the first to be completed, sits just east of Elwert Rd. and south of the roundabout.Cleared vegetation and formwork for bents 3 and 4 clarify the bridge path between Hwy 99W and Elwert Rd., with the eventual connection across the highway to the YMCA building.By August 2024, bents 3, 4, and 5 were complete along with the lower gabion wall tier of the west approach embankment.West approach embankment continues behind the completed gabion retaining walls.The final bents, 1 and 2, will be placed at the edges of the stormwater point following utility relocations. This could make them more accurately described as “piers”. They will be taller and wider than the others to make up the pond grade and the wider change in angle required to encircle the roundabout. Elevation view of the completed bent 3, finished in “Mt. St. Helens Gray”.Each bent features two trapezoidal, 28″ thick concrete walls tapered at 5 degrees. The resulting void contrasts with the solid faces and will be lit with a colored “lantern” effect. The gabion walls at the base of the west approach feature decorative rock facing to blend the terraced embankment into the future landscape.Structural soil fill is compacted in layers to bring the west approach grade up to the concrete retaining wall foundations.Round HSS steel members are laid out in the fabrication shop for the first arch, the main span 5 over highway 99W.Sub-components are fabricated and laid out for welding in the shop. Rounded and angled steel plates will connect stainless steel rods and struts to the arches.Steel fabrications are prepared for elements across the project, including the east approach ramp columns, deck beams, and the deck edge fascia/lighting trough. Complex steel shop assemblies form transitions from upturned channels to downturned beams and railing connections for the east approach landing.Two of the steel “belvederes” are prepared for galvanizing. These features will be located between each bridge span and include a pole light to be mounted over the triangular brackets.Curved, 10″ diameter round HSS cross bracing is fit up and cut to size in the fabrication shop, then will be welded together on site.The end connections from the arches to the deck are assembled in the shop in pairs.The deck beams and chord are laid out in the fabrication shop for the 14ft wide by 194ft long main span 5 over highway 99W. A completed steel “deck chord” assembly is prepared for painting in the shop. The assembly includes the structural round HSS arch tie, shaped connection plates for the truss tension rods (on alternate sides of the fascia), a flared fascia plate, the lighting trough, and vertical connections for the railing posts.Curved cross bracing and arch chords for span 5 over highway 99W are staged for painting.West approach construction continues with formwork for the west abutment rising behind the gabion walls.The integrated preconstruction mockup, located on site in the staging yard, features a wide range of project conditions condensed into a small space to validate workmanship, detailing, and integration between trades.The bridge deck will be illuminated through hundreds of small LED fixtures set into the stainless steel railings, seen here on the preconstruction mockup.The bridge deck lighting is tested on the preconstruction mockup, capturing half of the 14ft bridge width at the extended platform. Exterior of the preconstruction mockup with bridge deck lighting. The mockup was used to finalize the fixture orientation (tilted closer to the bridge deck, as is mockup up on the left section).The mockup includes the unique stainless steel rod-supported cable mesh railing system and many of its details across the bridge and approaches.A single 4ft long color-changing light fixture is installed on the mockup to test the architectural lighting system integration with the design. The bridge will have a total of 214 of these fixtures, enabling countless lighting designs.The color-changing architectural fixtures recess into a hidden steel trough in the bridge curb, capped in stainless steel to match the railing system and reflect the light.Color-changing mockup lights illuminate a piece of sonotube, which was used to represent the design with uplights casting to the round arches above the deck.The integrated preconstruction mockup will remain on site for reference until all relevant final work is installed.Rebar is installed for the concrete retaining walls at the upper tier of the west approach, revealing the curved pathway.The last section of the west approach will be a void concrete box, being formed here, to reduce the height of the embankment.Construction of the two bents between the west abutment and bent 3 waits for utility relocations around the stormwater pond.The running track on the second level of the YMCA building overlooks the bridge alignment from completed bent 5 across the highway and onto Sherwood High School.Substructure work is complete on each side of the highway for installation of the main bridge span.An at-grade view across the bridge alignment from bent 5 to bent 4, across highway 99W.The east approach will include a slender elevated ramp structure to avoid blocking the YMCA building with fill.The lawn in front of the YMCA building is graded to prepare for steel assembly and the eventual east approach ramp construction.The main span 5 over highway 99W will be fully assembled in the former YMCA lawn so that it can be lifted into place during a single weekend highway closure.The concrete void box is completed at the west approach, and ready for its structural deck lid.West approach construction continues with formwork for the concrete retaining walls at the top of the embankment.Formwork is stripped at the west abutment to reveal the concrete formliner pattern that contrasts with the rock-faced gabion walls and rip rap at the stormwater facility.A crane installs steel soldier piles to support excavation for bent 1 construction in the stormwater pond, as the west approach embankment nears completion.The concrete retaining walls atop the west approach embankment curve alternately to reflect the bridge elevation massing.Bridge span 1 will spring off of the completed west abutment and across Kruger Rd. This will be the last bridge span installed as onsite work shifts to the more compact east approach.Excavation shoring for bent 1 begins to fill the remaining gap in the bridge alignment and clarify its final footprint.The west approach is graded up close to the final pathway alignment, climbing above the HS practice field to reach the bridge.
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