- Taxiway Bypass, Widening & Reconstruction, Washington Dulles
This project consisted of three major elements:
- A new bypass taxiway
- The widening of the existing taxiway
- The reconstruction of Taxiway K
The bypass taxiway portion consisted of the design of a 700-foot-long bypass taxiway. The bypass taxiway was needed to improve the airfield operations by providing air traffic controllers the ability to modify the order of the aircraft queuing for takeoff.
The taxiway widening included nearly 1,400 feet of an existing taxiway. The existing taxiway centerline was essentially relocated 137.5 feet south, which allowed the adjacent hold block to increase in size by 137.5 feet to accommodate the storage of wide-body aircraft. Due to the locations of adjacent, existing connector taxiways, additional taxiway widening was designed to allow for cockpit-over-centerline turning movements, allowing pilots to move aircraft more quickly through the takeoff queuing area.
The bypass taxiway and taxiway widening portions of the project consisted of more than 35,000 square yards of portland cement concrete (PCC) pavement underlain by a cement-treated base course, an aggregate base course and a geotextile fabric.
The taxiway reconstruction consisted of the removal and replacement of approximately 3,000 feet of the existing taxiway. The Taxiway K reconstruction consisted of the replacement of nearly 25,000 square yards of PCC pavement. The existing 40-year-old pavement was exhibiting signs of structural failure.
An extensive surface water drainage analysis was performed due to the relatively large increase in impervious area that the project would create, combined with the limited capacity of the existing drainage system. The analysis evaluated more than 70 acres of surface area and nearly 8,000 linear feet of existing and new drainage pipe. To properly accommodate the increased runoff portions of the existing drainage system were rerouted or replaced with larger pipe.
To facilitate removal of subsurface water beneath the pavements, a network of nearly 12,000 linear feet of underdrains were designed around the perimeter of the pavement areas and beneath thickened edge expansion joints. Due to the addition of the bypass taxiway and the existing numbering scheme for the seven existing connector taxiways, the signage for this east runway complex was revised to accommodate the new taxiway. The airfield signage work consisted of adding or modifying 40 airfield signs. The project also included pavement marking, erosion control, airfield lighting, and reprogramming of the Airfield Lighting Control System’s mimic screens.