Dynamic Risk Assessment of Karst Tunnel Collapse Based on Fuzzy-AHP: A Case Study of the LianHuaShan Tunnel, China

Table 8

Classification of various factors.

Classification of factors		I	II	III	IV	V
Grade of surrounding rock	C111	I, II	III	IV	V	VI
Bias	C112	≤10°	10°–20°	20°–30°	30°–40°	≥40°
Unfavorable geology	B12	No fault layer	Small faults	Medium faults	Structural plane is developed	Structural plane is developed strongly
Scale of karst caves	C131	No cave	Small	Medium	Medium-large	Large
Location of karst caves	C132	Bottom of tunnel	Bottom-side wall of tunnel	Side wall of tunnel	Side wall-arch of tunnel	Arch of tunnel
Thickness of rock plate	C133	Thick	Medium	Thin	Intrude into the tunnel contour partly	Cave intrude into tunnel contour
Groundwater	C141	Undeveloped	Weak developed	Development	Abundant	Very rich
Water seepage on the face	C142	No water seepage	The face is wet	Dropwise seepage	Femoral seepage	To gush or eject
Tunnel depth	B21	>40 m	20 m–40 m	10 m–20 m	5 m–10 m	<5 m
Tunnel width	B22	<7 m	7 m–10.5 m	10.5 m–14 m	14 m–17.5 m	>17.5 m
Excavation method	C311	Very reasonable	Reasonable	Basically reasonable	Less reasonable	Unreasonable
Advance support	C312	Very reasonable	Reasonable	Basically reasonable	Less reasonable	Unreasonable
Grouting	C313	Excellent	Good	Average	Weak	Insufficient
Blasting disturbance	C314	Negligible	Weak	Moderate	Large	Huge
Construction machines and equipments	C321	Excellent	Good	Average	Insufficient	Poor
Quality of constructors	C322	Excellent skills	High skills	Average skills	Lack skills	Poor skills
Management level	C323	Rich experience	Strong experience	General experience	Lack experience	Poor experience
Advanced geological prediction method	B41	Excellent	Good	Average	Weak	Insufficient
Reliability and analysis of data	B42	Excellent	Good	Basically reliable	In doubt	Insufficient or unreliable
Information feedback	B43	Excellent	Good	Average	Weak	Poor