Observed Ground Pressure Acting on the Lining of a Large-Diameter Shield Tunnel in Sandy Stratum under High Water Pressure

Table 3

Observed total earth pressure acting on the lining on the crown and the theoretical calculations.

Section	Section-a (ring 479)	Section-b (ring 1094)	Section-c (ring 1210)	Section-d (ring 1384)
Overburden soil depth over tunnel outer diameter	3.04	1.34	1.15	1.11
Calculated by full total overburden ground pressure (kPa)	632.53	561.81	494.06	414.53
Terzaghi’s reduced pressure plus hydrostatic pressure (kPa)	457.35	511.54	450.66	372.13
Observed vertical total earth pressure (kPa)	548.92	465.73	396.94	323.84
Observed vertical total earth pressure over full overburden ground pressure	0.87	0.83	0.80	0.78
Observed vertical total earth pressure over calculated Terzaghi’s reduced pressure plus hydrostatic pressure	1.20	0.91	0.88	0.87
Observed vertical total earth pressure over theoretical hydrostatic	1.79	1.10	1.06	1.09