Experimental Study on Measurement of Drag Coefficient of Sandy Soil Nonlinear Vadose

Table 6

Comparison of the fitting accuracy between the modified empirical formula and the empirical formula

Particle size range (mm)	Dry density (g/cm^3)	CU	CC	Fitting accuracy comparison ()
				0.1–0.25	1.446	1.00	1.00	0.9818	0.9818
1.461	1.00	1.00	0.9781		0.9781
1.640	1.00	1.00	0.9434		0.9434
0.25–0.5	1.640	1.00	1.00	0.4036	0.053
	1.585	1.00	1.00	0.5895	0.333
	1.599	1.00	1.00	0.2194	0.005
0.5–1	1.694	1.00	1.00	−4.6715	0.189
	1.660	1.00	1.00	−0.1573	0.966
	1.640	1.00	1.00	−2.1310	0.629
1–2	1.693	1.00	1.00	0.1536	0.902
	1.729	1.00	1.00	0.0296	0.894
	1.767	1.00	1.00	−0.0111	0.904
2–5	1.640	1.00	1.00	−0.1340	0.819
	1.715	1.00	1.00	−0.0113	0.820
	1.738	1.00	1.00	−0.2129	0.853
0.1–5	1.8190	6.00	0.75	−1.9065	0.929
	1.8190	6.00	1.00	−1.5727	0.909
	1.8190	6.00	1.00	−2.1685	0.952
	1.8190	6.25	1.00	−2.1786	0.951
	1.8190	5.50	1.00	−2.0925	0.963