Stability Analysis of Shield Excavation Face Based on Particle Flow in Different Depths of Sandy Gravel Stratum

Table 1

Testing mesoscopic parameters.

Poisson ratio (test)	Cohesion (test)	Internal friction angle (test)	Equivalent modulus	Coefficient of friction	Porosity	Stiffness ratio	Normal contact stiffness
Parameters (unit)	c (kPa)	Φ (°)	Ec (Pa)	c		Kn  Ks^−1	Kn (Pa)
0.3	143.9	35.9	2.85e7	0.24	0.28	3	3.5e6