The study reported here was designed to examine the impact of background meteorological conditions on the propagation of noise from urban freeways in the Phoenix area. The aim was to understand and predict how sound waves emanating from highways respond to the vertical profiles of atmospheric temperature gradients and velocity shear, so that sound measurements can be interpreted with regard to the environmental variability.

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.