Influence of Particle Orientation on the Performance of Geogrid Reinforced Ballast

Table 1

Model parameters.

Category	Ballast	Geogrid
Particle density (kg/m^3)	2700	800
Porosity	0.45	—
Contact normal stiffness (kN/m)	0.52 × 10^5	1.77 × 10^4
Contact normal stiffness (kN/m)	0.52 × 10^5	0.88 × 10^4
Coefficient of friction	0.8	0.5
Parallel bond normal stiffness, knp (kN/m^3)	—	5.68 × 10^8
Parallel bond shear stiffness, ksp (kN/m^3)	—	5.68 × 10^8
Parallel bond normal strength, snp (kN/m^2)	—	4.56 × 10^5
Parallel bond shear strength, ssp (kN/m^2)	—	4.56 × 10^5
Parallel bond radius multiplier	—	0.5