Experiments on Reducing Negative Skin Friction of Piles

Table 3

Model 2.

Moisture content (%)	Vertical force (kN)	Compressive stress (kPa)	Horizontal force (kN)	Friction strength (kPa)	Friction coefficient	Average friction coefficient
21	10	47.26	1.49	7.04	0.149	0.15
	20	94.52	2.80	13.23	0.140
	30	141.78	4.42	20.89	0.147
19	10	47.26	2.58	12.19	0.258	0.23
	20	94.52	4.44	20.98	0.222
	30	141.78	6.03	28.50	0.201
17	10	47.26	2.83	13.37	0.283	0.27
	20	94.52	5.84	27.60	0.292
	30	141.78	7.13	33.70	0.238
15	10	47.26	2.93	13.85	0.293	0.29
	20	94.52	5.79	27.36	0.290
	30	141.78	8.72	41.21	0.291
13	10	47.26	2.60	12.29	0.260	0.23
	20	94.52	4.35	20.56	0.217
	30	141.78	6.15	29.06	0.205