Mariposa Community Causeway
Project Details
Project Story
The Challenge
Connecting the Laurel Woods neighborhood to Mariposa Community Park required an elevated pathway spanning a wetland while addressing both constructability and long-term material performance. The 10-foot-wide boardwalk spans just over 291 feet and features weathering steel (Corten), which develops a protective patina over time. A key engineering challenge was preventing galvanic corrosion where the weathering steel columns met the powder-coated helical piles, while accommodating the two-inch placement tolerance of the piles.
Our Response
Miller Consulting Engineers (MCE) designed a panelized structural system that allowed each span to be fabricated off-site, transported to the project, and installed in its final position with minimal field assembly. To address the corrosion concern, MCE incorporated concrete pile caps to separate the dissimilar metals while accommodating the required helical pile placement tolerance. This approach addressed a critical structural detail while supporting efficient installation.
The Outcome
The completed causeway provides a durable, elevated connection between the Laurel Woods neighborhood and Mariposa Community Park, improving pedestrian access across the wetland. Panelized construction reduced the need for on-site assembly, while the carefully detailed connections addressed material compatibility and long-term performance. The project demonstrates MCE's focus on practical structural solutions that balance durability, constructability, and cost efficiency.
Gallery
Project Team
Project Metrics
- Location
- Tualatin, OR
- Bridge
- 290 ft · 10 ft
- Construction Budget
- $1.5M
- Division
- Non-Building Structures
Project Partners
- Civil Engineer our client
- AKS Engineering & Forestry
- Project Owner
- City of Cornelius
Awards
- Project of the Year American Public Works Association (Oregon)
