Project Engineer I Drummond Carpenter, PLLC, Florida, United States
Abstract Submission: In the mid-2000s, abandoned sections of railroad berms located in Sarasota County, Florida, were converted into a multi-use activity trail for local residents referred to as the Legacy Trail. Adjacent to the Legacy Trail lies a north-south segment of upland cut ditch (i.e., the Legacy Trail Canal) that was constructed in the early 1900s as part of a railroad system to provide fill for the railroad berm construction and drainage along the railroad routes to prevent flooding along the tracks. The County has received complaints regarding the erosive condition of the canal and potential property loss from property owners along the canal segment and in response, requested for an erosion control and slope stability investigation to be performed. To evaluate the velocities and shear stresses within the canal segments, an existing condition HEC-RAS model was developed for the study area. This presentation will highlight the major inputs developed for the model such as the terrain using survey and available LiDAR data, computational mesh, breaklines from existing survey, boundary conditions from an updated 1D model, and spatially varied manning’s roughness layer. Five concepts to improve slope stability were developed following the existing conditions modeling effort, of which three were selected for further investigation and were modeled using either a modified version of the existing conditions HEC-RAS model or a modified version of the 1D model, as appropriate.
