Model Test on the Vibration Reduction Characteristics of a Composite Foundation with Gravel Cushion under Different Seismic Wave Amplitudes

Table 2

Physical properties of three gravel aggregates of different gradations.

Aggregate gradation	Particle size (mm)	Minimum dry density (g/cm^3)	Maximum dry density (g/cm^3)	Coefficient of uniformity	Coefficient of curvature
Single-sized	2–5	1.32	1.58
Two-sized	2–10	1.35	1.66
Continuously grade	0–10	1.36	1.68	5.02	1.86