Experiments on Reducing Negative Skin Friction of Piles

Table 4

Model 3.

Moisture content (%)	Vertical force (kN)	Compressive stress (kPa)	Horizontal force (kN)	Friction strength (kPa)	Friction coefficient	Average friction coefficient
21	10	47.26	1.17	5.53	0.117	0.13
	20	94.52	2.84	13.42	0.142
	30	141.78	4.28	20.23	0.143
19	10	47.26	2.71	12.81	0.271	0.25
	20	94.52	4.73	22.35	0.237
	30	141.78	6.85	32.37	0.228
17	10	47.26	4.09	19.33	0.409	0.39
	20	94.52	7.72	36.48	0.386
	30	141.78	11.12	52.55	0.371
15	10	47.26	5.06	23.91	0.506	0.51
	20	94.52	10.40	49.15	0.520
	30	141.78	15.02	70.98	0.501
13	10	47.26	5.30	25.05	0.530	0.53
	20	94.52	10.57	49.95	0.529
	30	141.78	15.76	74.48	0.525