■掲載誌：日本建築学会技術報告集　No.1, pp.89-94
■発行所：日本建築学会
■発行：1995/12

Nodular precast piles have come a long way since the idea was perceived more than six decades ago as a means of enhancing shaft friction. Over the years, nodular piles of different cross-sectional shapes made of reinforced concrete and prestressed concrete have been in use. Recently, prestressed precast high strength concrete (PHO nodular piles have proved to be a favorable foundation option for low-rise to medium-rise buildings located at deep soft soil sites. These piles are unique in that the load bearing resistance is primarily derived from adhesion and friction along the pile shaft. A rational approach to the development of a reliable method for the design of PHC nodular piles considering readily available soil parameters is presented. Previous studies on model and full-scale tests have clarified the load bearing mechanism of nodular piles. However, the load bearing capacity is influenced by the method of installation. PHC nodular pile installed by inserting into a drilled hole and bonded to the ground by cement grout, often referred to as the bored pile, is considered in this study. Considering that the soil type and the standard penetration test (SPT) N-values constitute the basic information from site exploration records in Japan, attempt is made to develop a simple correlation between these parameters and the bearing capacity.