|PROJECT||Taxiway B and Apron Rehabilitation|
The project was done by EGS personnel while employed by another firm. It consisted of the reconstruction of failed Taxiway Bravo and the General Aviation parking apron. FAA and FDOT grant funding was provided for the work.
The existing pavement section consisted of two to three inches of bituminous surface constructed directly on sand clay subbase or sand subgrade. The pavement section was revised to recycle the existing surface into eight inches of the sand clay or sand, and use the resulting mix as stabilized subgrade. This achieved field and laboratory soaked CBR’s of around 50. The excellent result enabled a pavement section of two inches bituminous surface on four inches of lime rock base.
A major issue in the reconstruction of the apron and taxiway was the airfield drainage system. The airport did not have a master drainage plan and none was included in the project scope. Pipes draining the airport infield were partially collapsed and almost nonfunctional. Additionally, previous excavations for earthfill in an already depressed area had created a wetland attracting wildlife and serving as a flood storage area. The consulting team did a mini master drainage plan to address this issue such that piping replaced during construction would have adequate capacity for future airside development already in the JACIP funding cycle or in the approved airport master plan. The piping replacement design increased the flow capacity beneath existing taxiways and beneath the apron to the airport discharge. However, to avoid off-site flood impacts from the increased flow capacity, a pond for flood control was required. This was constructed to FAA suggested criteria with 2H: 1V side slopes beneath the water surface. To minimize required wetland mitigation costs, the system includes two islands. This was permitted with the St. Johns River Water Management District and the U.S. Army Corps of Engineers. The fill material from the pond construction was used to regrade and smooth the existing airport infield, and to the extent possible with the materials available, to remove two wetlands (mitigated off airport property) that were acting as wildlife attractants in the infield. The airport received the 2014 J. Bryan Cooper Environmental Award from the Florida Airports Council.