Design of Reinforced Slope - Queens NY
Siefert Associates, LLC (SA) recently completed the design of a 15 ft. high reinforced sloped embankment to support a new Shared Use Path (SUP) in Queens, NY. This geotechnical engineering effort was part of the Kew Gardens Interchange Infrastructure and Operational Improvement Project. The tight horizontal clearance between the SUP and the Grand Central Parkway to the south prevented the installation of a typical unreinforced embankment with a flatter slope.
The SA scope of work included first reviewing the subsurface soil conditions, determining the design soil parameters, quantifying the surcharge loading, and developing the geometry of the proposed slope. Next, a slope stability model was built to predict the soil’s behavior and calculate the lateral forces acting at different elevations. These results were used to identify the geogrid requirements. The stability of the embankment under static and seismic loading conditions was assessed, and a bearing capacity analysis of the soil under the embankment was performed. The design of the embankment also included evaluating underdrains, slope erosion control measures and vegetative cover.
Figure 1: View of stability model.
Figure 2: Photo of site prior to construction.
