The Sedona Airport is situated atop a mesa in Yavapai County, and Runway 3-21 does not have runway safety areas (RSAs) that meet Runway Design Code (RDC) B-II standards. During the development of the Sedona Airport Master Plan, four RSA improvement alternatives were discussed for the RSAs. The recommended alternative includes constructing fill areas with a retaining wall at each runway end. The fill areas will provide for the correct end or RSA length of 300 feet with a width of 150 feet.
Dibble provided concept design services, including structural feasibility for the retaining wall. In addition, the team conducted a structural material evaluation and preliminary selection recommendation for the retaining wall. The feasibility assessment included several key factors such as cost, constructability, durability, performance criteria, environmental conditions, geological and topographic conditions, size, availability of materials, and aesthetics.
Based on the understanding of the project scope, Dibble recommended using a geofoam-backfilled, geosynthetic-reinforced mechanically stabilized earth (MSE) retaining wall with a reinforced shotcrete face and plastered rock finish. Dibble is currently providing survey, geotechnical investigations, aircraft fleet mix validation, 15% geometric design, preliminary grading and drainage, earthwork evaluation, haul routes, site access, stockpile evaluation/disturbance, and preliminary construction costs for the improvements.