Effects of Water Inrush from Tunnel Excavation Face on the Deformation and Mechanical Performance of Shield Tunnel Segment Joints

Table 3

Pore pressure and the corresponding water head difference at the excavation face.

Pore water pressure at excavation face (kPa)	0	20	40	70	100	130	160	No pore
Reduction of water head difference at excavation face (m)	18.2	16.2	14.2	11.2	8.2	5.2	2.2	0