Comparison of SPT-based design methods for vertical capacity of piles installed by Rotary Cutting Press-in

The applicability of the Press-in Method to hard grounds has been significantly improved by the development of Rotary Cutting Press-in (RCP), where vertical and rotational forces are simultaneously applied to a pile with base cutting teeth. Although RCP piles are usually used for retaining walls, there have been some cases where they are used for foundations. Several SPT-based design methods for RCP piles have been prepared so far. Some of these are based on existing design codes in Japan for piles installed by other piling methods, which are intended for specific construction fields (roads and railways). This paper overviews these existing SPT-based design methods for RCP piles, and proposes another method by making adjustments on the existing design method for the field of buildings in Japan, based on the results of five static load tests on RCP piles.