Risk Identification and Assessment during the Excavation of the Deep Foundation Pit

Table 2

Criteria for risk levels.

Level	1	2	3	4	5
Possibility	Frequent	Possible	Unmeant	Infrequent	Impossible
Probability	>0.1	0.01∼0.1	0.001∼0.01	0.0001∼0.001	<0.0001