Proposed point bearing load transfer function in jointed rock-socketed drilled shafts

The point bearing behavior of rock-socketed drilled shafts under axial loading is investigated by numerical analysis and a load transfer approach (q–w). A numerical analysis using the distinct element method (DEM) is carried out to investigate the effects of pile diameter and the elastic modulus, discontinuity spacing and the inclination of rock mass on the point bearing behavior. The emphasis is quantifying the point bearing mechanism by taking rock discontinuity into consideration based on field loading tests performed on 39 instrumented piles. A new hyperbolic q–w function is proposed considering the point bearing resistance influence factors, including rock mass discontinuity. Through comparisons with other field data, the proposed q–w function represents a significant improvement in the prediction of the point bearing load transfer characteristics of jointed rock-socketed drilled shafts.