MAX Orange Line & Tilikum Bridge

CLIENT Tri-County Metropolitan Transportation District of Oregon                 (TriMet)

Location Portland, OR

TriMet’s Portland to Milwaukie Light Rail (PMLR), East Segment transit project (new MAX Orange Line) provided a necessary link from downtown Portland to inner Southeast Portland and the Milwaukie city center.

Photo provided by TriMet

Photo provided by TriMet

Photo provided by TriMet

The centerpiece of the TriMet PMLR transit project was the Tilikum Bridge, a cable-stayed bridge crossing the Willamette River. The project encompassed approximately six miles and consisted of 10 bridges, ranging between less than 100 feet long (single-span) to more than 1,600 feet long (11 spans); 45 cut-and-fill retaining walls more than a mile long and up to 32 feet high; and underground utility relocations, including up to 40-foot-deep excavations with shoring and dewatering.

The route featured extremely variable geologic conditions, and the project required heavy construction in a highly developed urban corridor. These design challenges were set against the backdrop of a very intricate construction sequence and aggressive Design/Build schedule. Shannon & Wilson evaluated site-specific seismic hazards, developed foundation design alternatives, completed final foundation design, and reviewed construction drawings and specifications. We completed a large-scale geotechnical investigation program of 169 field exploration points and performed laboratory testing. During construction, we continued as the owner’s representative and provided construction consultation and observation as the geotechnical engineer of record.

transportation Transit
GIS / Database Management Geotechnical Engineering Contamination / Remediation Geologic Hazards Design-Build Construction Management


ACEC Oregon Engineering Excellence Grand Award


Adrian Holmes

Alia Hubbard
Environmental Staff

Travis Nguyen
Senior Associate

Park Piao
Vice President

Cody Sorensen
Senior Geologist

James Walters

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