Dispersant for Reducing Mud Cakes of Slurry Shield Tunnel Boring Machine in Sticky Ground

Table 1

Slurry properties.

Slurry	Seepage discharge (g)		Segregation ratio (%)
	60 s	30 min	2 h	24 h
Pure bentonite slurry	2.34	14.05	0.00	0.00
Slurry with 4% dispersant	1.17	7.27	0.00	1.60
Slurry with 6% dispersant	1.23	7.58	0.00	1.00
Slurry with 8% dispersant	1.38	8.84	0.00	0.96
Slurry with 10% dispersant	1.58	9.82	0.00	0.88