Abstract Description: The Willamette Falls flow control structure is located on the Willamette River between Oregon City, Oregon and West Linn, Oregon. Constructed in 2007, this structure was part of efforts to protect fish and improve fish passage. The concrete structure is 240 feet wide and is divided into three bays, each with unique geometry, spans, and piers. Each bay contains an inflatable rubber dam that can be independently raised and lowered. A hole discovered in one of the rubber dams necessitated the design of a new bulkhead system for repair.
The Willamette Falls Bulkhead Project successfully designed and implemented a steel bulkhead system at the existing flow control structure. This custom “large-scale stoplog” system could be applied to other challenging sites and applications. The design features long-span custom fabricated stoplogs that can be stacked. The analysis involved three-dimensional finite element modeling of each segment and additional modeling of interaction effects for the final condition with all the segments stacked. A key focus of the project was refining the details to minimize installation and removal time on the river.
The project effectively tackles the unique challenges and constraints posed by structures originally built without full consideration for future repairs. Various challenges can arise from repairing hydraulic structures when there is not a proper location to seat a bulkhead, manageable spans, or similar geometry between bays. This paper presents lessons learned and design considerations that can be applied to other hydraulic structures requiring unique solutions for temporary closure or isolation for in-water work.
Learning Objectives:
Learn about innovative bulkhead solutions for hydraulic structures.
Learn about critical details to minimize installation and removal time at a difficult site.
Learn about design considerations that can be applied to other hydraulic structures requiring unique solutions for isolation for in-water work.
