Estimating the axial side shear resistance of drilled shaft rock sockets is directly related to the unconfined compressive strength of the bedrock. Typically, the average unconfined compressive strength value is calculated from a range of laboratory test results and is used to estimate the side shear of the bedrock.

Measurements

This paper illustrates the results from a full-scale axial load test performed on an 8.5-foot-diameter drilled shaft rock socket.  The authors further compare measured side shear values to estimated values for two different rock strata.

This geotechnical effort is part of a project involving replacement of the existing structure that carries S.R. 0040 over the Youghiogheny Reservoir in Fayette and Somerset Counties, PA. 

Borings

Subsurface conditions are also discussed, in addition to designing the drilled shaft rock sockets for axial and lateral resistance. Gannett Fleming performed 15 soil borings to investigate the subsurface conditions at the proposed pier locations for the alternate eight-span structure.
 

^ Diameter shaft  reinforcement cage.	^ Completed shafts for pier bent.