Study on the effects of bored precast pile toe shape on vertical bearing capacity
Study on the effects of bored precast pile toe shape on vertical bearing capacity
A bored precast pile is installed using a construction method that enhances vertical bearing capacity by forming an enlarged grouted base at the pile toe. This base is created through soil mixing with cement milk, effectively increasing the pile toe diameter and thereby enhancing the vertical bearing capacity. Therefore, the enlarged grouted base serves as a critical factor in improving the piles vertical bearing capacity.
The vertical bearing capacity of the pile is primarily influenced by the geometry and strength of the pile toe and the enlarged grouted base. In particular, a precast pile installation method with concurrent augering, where the pile is embedded while the surrounding soil is simultaneously excavated, is widely used in Japan. In this method, the pile toe shape significantly affects not only the vertical bearing capacity but also the constructability. However, limited research has been conducted on how pile toe geometry affects the vertical bearing capacity.
In this study, vertical loading tests using a pressurized tank were conducted on model steel pipe piles, with the pile toe shape set as a variable, in order to improve constructability. The effects of the pile toe shape on the vertical bearing capacity and the failure mode of the grouted base were investigated. The results clarified the relationship between the pile toe shape and the vertical bearing capacity.
Genki Yanagi; Shuichi Shimomura; Yuki Domyo
11th International Conference on Physical Modelling in Geotechnics (ICPMG2026)
Special Session 1: Physical modelling – from Practice/Industry to Academia
https://doi.org/10.53243/ICPMG2026-159