Investigation on Dynamic Stability of Cement-Stabilized Expansive Soil Subgrades Subjected to Repeated Heavy-Haul Train Loads

Table 5

Critical dynamic stress.

Category	σd (kPa)	Frequency (Hz)	Critical dynamic stress (kPa)	Mean value (kPa)
Virgin expansive soil	30	1	22.3–31.5	26.90
	60	1	28.6–34.9	31.75
	30	5	21.6–30.8	26.20
	60	5	27.2–33.7	30.45
Expansive soil improved with 3% cement content	15	1	151.2–185.7	168.45
	30	1	157.5–203.5	180.50
	60	1	182.3–233.1	207.70
	15	5	148.8–181.4	165.10
	30	5	152.3–200.1	176.20
	60	5	180.6–229.6	205.10
Expansive soil improved with 5% cement content	15	1	142.5–208.1	175.30
	30	1	148.3–233.5	190.90
	60	1	202.5–249.7	226.10
	15	5	147.8–199.6	173.70
	30	5	145.6–231.7	188.65
	60	5	201.5–246.2	223.85
Group A filling	15	1	100.0–125.2	112.6
	30	1	100.1–125.2	112.7
	60	1	125.1–150.6	137.9