Uncertainty Analysis on Risk Assessment of Water Inrush in Karst Tunnels

Table 4

Parameters of probabilistic distribution for index .

		Mean	Standard deviation σ
Formation lithology		75	1.5
Unfavorable geological conditions		60	1.5
Groundwater level (m)		>75	1.5
Landform and physiognomy (proportion of negative landform area)		40	1.5
Modified strata inclination (°)		16	1.5
Contact zones of dissolvable and insoluble rock		70	1.5
Layer and interlayer fissures		65	1.5