DESIGN OF REINFORCED CONCRETE DRILLED SHAFTS IN POOR SOILS: CASE STUDIES

摘要

The purpose of this paper is to discuss some of the challenges encountered during the design of two reinforced concrete drilled shafts situated in poor soils and subject to very large reactions. These difficulties include conforming to limitations on deflections, shaft top projections, effects of frost depths, evaluation of skin friction contribution to axial resistance and rebar arrangement. Two recent designs, where permanent steel casings are used to encompass the drilled shafts, are presented. Suggestions for the future include performing geotechnical investigation well in advance to avoid later-stage problems and to include skin friction while estimating axial or vertical load resistance.