PEER has just published Report No. 2018/06: “Estimation of Shear Demands on Rock Socketed Drilled Shafts subjected to Lateral Loading.” It was authored by Pedro Arduino, Long Chen, Christopher R. McGann.
This report presents results of an evaluation study on the applicability of current design procedures (based on p-y curves) to the analysis of large-diameter shafts socketed in rock, and the identification of enhanced moment transfer mechanisms not considered in current design methodologies. For this purpose simplified models, and possible three-dimensional (3D) finite-element method (FEM) models are studied to shed some light on the response of drilled shafts socketed in rock. A parametric study using p-y and considering a wide range of rock properties and rock-socket depths, different criteria to define the soil and rock p-y curves, different beam theories, and different interface frictional resistances are presented and compared with 3D FEM simulations. A new element is discussed to account for the shaft toe and underlain rock interaction, which could provide benefit to reduce shear demands when the socket is shallow.