I-75 Canal Improvements: 2D Hydraulic Modeling
Client: South Florida Water Management District (SFWMD, as sub-consultant of Stanley Consultants)
The SFWMD was considering enhanced conveyance scenarios that may cause more scour and erosion at the I-75 bridges. Hence, a detailed 2D / 3D Computational Fluid Dynamic (CFD) hydraulic modeling of the waterway intersection was required to evaluate potential scour and erosion at the two bridges.
LAGO developed a comprehensive 2D hydraulic modeling of the waterway intersection between the I-75 canal and Golden Gate Main canal by using the RiverFlow2D software. Two channel bathymetry scenarios were considered (i.e., excavation vs reinforcement) as well as two high flow regimes with high and low stages. The triangular grid had variable sizes from 5 feet near the boundaries to 0.5 feet around the bridge piers, where more resolution was needed to compute the flow field. An equivalent 3D simulation with that 2D model resolution and simulation period had impractical run times, and the 3D modeling was discarded for this application.
This 2D modeling analysis concluded that changes in channel bathymetry would not have a significant impact on the stages at the I-75 canal or adverse impacts on the potential for erosion at the I-75 bridges under the extreme flow conditions evaluated. However, reinforcing “the boot” is the preferred option for generating less potential of scour and erosion at the north-bound bridge.