Excess Pore Water Pressure and Ground Consolidation Settlement Caused by Grouting of Shield Tunnelling

Table 1

The empirical values of A (Skempton [19]).

Types of clay	A
Highly sensitive cohesive soil	0.75–1.5
Normally consolidated clay	0.5–1
Compacted sandy clay	0.25–0.75
Slightly overconsolidated clay	0.2–0.5
General overconsolidated clay	0–0.2
Highly overconsolidated clay	–0.5 to 0