Investigation on Dewatering of a Deep Shaft in Strong Permeable Sandy Pebble Strata on the Bank of the Yellow River

Table 3

Comparison of excavation depth and safe water table (m).

Excavation depth	Safe water table outside the shaft	Drawdown required
10	-10	0
20	-10	0
30	-10	0
31.20 (critical excavation depth)	-10	0
35	-16.7	6.7
40	-25.4	15.4
45.1	-34.2	24.2