Concurrent Sessions B: Modeling and Design - 2-Dimensional Hydraulic Modeling of a Low-Head Dam Retrofit and Implications for Design
Location
Agriculture Production Theater, Oregon State University
Start Date
27-6-2013 1:30 PM
End Date
27-6-2013 1:50 PM
Description
Adaptive Hydraulics (AdH) was used to model a recently constructed low-head dam retrofit project in which boulders were used to create a step-pool sequence that allows fish passage. AdH is a 2-dimensional hydraulic model developed by the US Army Corps of Engineers. Detailed survey data of the retrofit project was taken by using a 3D scanner during a dry period in which no water was flowing through the project. The 3D scanner is capable of creating an accurate 3D surface by generating points within millimeters of each other. AdH was used to model the existing retrofit project, and the results were compared to HEC-RAS results. HEC-RAS, a 1-dimensional hydraulic model that was also developed by the US Army Corps of Engineers, is often used in the design of in-stream structures and retrofit projects such as these because it is a well-known model, easy to use, and does an excellent job of predicting upstream impacts a project may cause; however one of its primary limitations is its inability to model localized velocities. The modeling effort with AdH provides a more detailed view of the hydraulics through all portions of the retrofit project in various flow conditions. In addition, various boulder spacing’s were modeled to determine impacts on velocities and forces that would act on individual boulders. Gaining a better understanding of localized velocities and forces enables the desktop design to incorporate a more natural boulder layout, which is beneficial for aesthetics. The natural boulder layout can also be used to create variable velocities through a given cross section at a given flow and could be used to target various fish species at various life stages in future designs.
Concurrent Sessions B: Modeling and Design - 2-Dimensional Hydraulic Modeling of a Low-Head Dam Retrofit and Implications for Design
Agriculture Production Theater, Oregon State University
Adaptive Hydraulics (AdH) was used to model a recently constructed low-head dam retrofit project in which boulders were used to create a step-pool sequence that allows fish passage. AdH is a 2-dimensional hydraulic model developed by the US Army Corps of Engineers. Detailed survey data of the retrofit project was taken by using a 3D scanner during a dry period in which no water was flowing through the project. The 3D scanner is capable of creating an accurate 3D surface by generating points within millimeters of each other. AdH was used to model the existing retrofit project, and the results were compared to HEC-RAS results. HEC-RAS, a 1-dimensional hydraulic model that was also developed by the US Army Corps of Engineers, is often used in the design of in-stream structures and retrofit projects such as these because it is a well-known model, easy to use, and does an excellent job of predicting upstream impacts a project may cause; however one of its primary limitations is its inability to model localized velocities. The modeling effort with AdH provides a more detailed view of the hydraulics through all portions of the retrofit project in various flow conditions. In addition, various boulder spacing’s were modeled to determine impacts on velocities and forces that would act on individual boulders. Gaining a better understanding of localized velocities and forces enables the desktop design to incorporate a more natural boulder layout, which is beneficial for aesthetics. The natural boulder layout can also be used to create variable velocities through a given cross section at a given flow and could be used to target various fish species at various life stages in future designs.
Comments
Jeff Weiss has almost 10 years of experience in river hydraulics, stream classification, monitoring, and restoration. His work has included stream restorations, one-and two-dimensional hydraulic and hydrologic modeling, and projects involving a broad range of water quality, storm water runoff, and flood protection issues. His passions lie in stream and ecosystem restoration.