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.

Research into the sensitivity and vulnerability of urban water systems in Arizona reveals that managers are more concerned about factors such as population growth projections, economic trends, and revenue flows. Reliance on groundwater resources in many cases obscures recognition of any direct impact of precipitation on water supply. Given the low level of perceived climate risk among many providers interviewed for this study, it would seem unlikely that climate information would be needed. However, pockets of sensitivity and vulnerability to climatic impacts do exist in the four study areas covered in this study.