Implementation of Geotextile T-Groins in Pinellas County, Florida

摘要

Since the late 1970s, nourished sand provided by the federal shore protection project at Upham Beach, Florida, has routinely eroded within two years of placement. The erosion problem is a result of the location of the beach immediately downdrift of a total littoral barrier and pre-control line construction in a seaward-advanced position. This 2,400-ft-long nourishment project is considered a "feeder beach" because fill is placed along the updrift end of a 2.5-mi region intended to receive sediment. The need to retain a protective beach and to address the negative public perception of a rapidly eroding project gave rise to the structural solution described in this paper. The geotextile T-groin project that was installed in 2005 included advance downdrift mitigation and a long-term monitoring plan. The structures were also designed to withstand extended exposure, high wave energy, and significant scour that typically occur at this location. Although construction of the $1.5 million project was challenging, the preliminary performance of the T-groins is promising. As a result of the structures, the public beach at the project site was 100 ft wider two years after the 2004 nourishment project, as compared to two years after the 2000 nourishment project. The T-groin project has successfully maintained Upham Beach with no downdrift impacts. Based on the performance of the temporary structures over the next several years, an application for similar rock structures may be submitted in the future.