Experiments on Reducing Negative Skin Friction of Piles

Table 7

Neutral point depth.

Force layer properties	Clay, powder soil	Sand above medium density	Self-weight collapsible loess	Gravel, pebble	Bedrock
Depth ratio of neutral point Ln/L0	0.5–0.6	0.7–0.8	0.77–0.8	0.9	1.0

Note. L_n and L₀ are the depth of the neutral point and the lower limit depth of the settlement and the deformation soil layer in the area surrounding the pile, respectively.