The Greater Phoenix Blue Chip provides quarterly consensus projections on general economic indicators and key construction measures from economists and real estate analysts and executives in the Phoenix metropolitan area. The construction forecasts are compiled in cooperation with Elliott D. Pollack and Company, a leading economic and real estate consulting firm based in Scottsdale, Arizona.

This report provides a simplified method to be used for evaluating the skin friction and tip resistance of axially loaded drilled shafts. A summary of literature and current practice was completed and then a comprehensive set of field and laboratory tests was performed. Several soil samples were collected from different sites from Arizona and surrounding states. Large scale direct shear apparatus was developed and used to determine the friction between soil and concrete. Finite element analyses were conducted on several prototype cases to determine effect of soil parameters such as dilation on the skin friction values. A step-by-step simplified approach was introduced to determine the skin and tip resistance of drilled shaft foundations in gravelly soils. An example application was presented to guide users in utilizing the simplified approach.