Direct Shear Test on Coarse Gap-Graded Fill: Plate Opening Size and Its Effect on Measured Shear Strength

Table 2

Peak and residual internal friction angle (φ) and cohesion (C) obtained by direct shear tests on G3 with six different plate opening sizes.

Opening size/(mm)	Peak values		Residual values
	5.0	53.3	160.0	51.56	38.65
10.0	39.1	66.5	27.28	16.49
15.0	37.0	59.5	26.30	22.13
20.0	38.3	51.5	29.79	17.48
25.0	34.1	43.3	25.88	0.00
30.0	27.8	51.3	20.52	5.30