Non-Displacement Pileの先端支持力推定のための地盤の「平均N値」に関する解析的一考察

抄録

Estimation of end bearing capacity of non-displacement piles is usually based on the equivalent SPT N-value around the pile toe However, there is on-going discussion about how the equivalent SPT N-value should be calculated In this paper, the load-settlement relation and end bearing capacity of non-displacement piles installed in ground layers with varying SPT N-values is investigated by numerical analysis based on finite element method The results indicate that the bearing capacity ls practically not affected by the soil above the pile toe level, while the soil within th range 2D (D pile diameter) below the pile toe level has large influence. Optimization program is utilized to propose the weighted average method of calculating the equivalent SPT N-values.