Little Goose Dam

Starbuck, WA

USACE Walla Walla District

Adjustable Spillway Weir-Little Goose Dam

GDM provided professional structural engineering and support services for the USACE Walla Walla District, Little Goose Dam’s Adjustable Spillway Weir. This project uses W36x170 main beams spanning 55’-0” with a maximum load during a critical lift of 200 kips. The beams are designed using elastic theory. We used Enercalc to analyze the intensity, shear, moment and deflection with MathCAD being used to perform all “hand calculations.” Complicated loading scenarios with fracture critical welding details have been designed. The project’s budget is $6.5 million with most being consumed on the structural aspects of the project. Deflection is limited to L/360 and the beam has cyclical loadings creating complex detailing. This project is relevant because it shows our ability to design steel in non-typical and dynamic applications.