Research Article

Evaluation of the Influence Caused by Tunnel Construction on Groundwater Environment: A Case Study of Tongluoshan Tunnel, China

Table 2

Criteria for assessment of the negative effects caused by tunnel excavation on groundwater environment [16].

Very weakWeakModerateStrongVery strong

[C11] average annual rainfall (mm)<600600~800800~10001000~1600>1600
[C12] average annual evaporation (mm)>800600~800500~600400~500<400
[C13] area of catchment zone (km2)<55~1010~3030~50>50
[C14] coefficient of rainfall infiltration<0.050.05~0.150.15~0.300.30~0.50>0.50
[C15] spatial relationship between the tunnel and geomorphologyOther (such as flat, protruding)Flat and basin-shapedAngular space and river crossingSide below the valley and river crossingRight below the valley and river crossing
[C16] capacities of reservoirs and lakes on the ground (m3)<11~1010~5050~300>300
[C17] flow of surface rivers (m3/s)<0.10.1~0.50.5~2.02.0~10.0>10.0
[C21] carbonate rocks exposure ratio (%)<3030~5050~7070~90>90
[C22] water yield property of aquifers<55~1010~1515~20>20
[C23] water pressure on the tunnel (Mpa)<0.50.5~1.01.0~3.03.0~5.0>5.0
[C24] development of foldsNo foldsFolds with undeveloped fissureFolds with moderately developed fissureFolds with developed fissureFolds with developed faults
[C25] development of fracture zonesRarely developedPoorly developedModerately developedDevelopedWell developed
[C26] formation lithologyMudstone, shale, or claySandstone or fine sandstoneGranite or igneous rockMetamorphic rockSoluble rocks including limestone, dolomite, and so forth
[C27] location of tunnel in horizontal and vertical hydrodynamic zoning of groundwaterRecharge area in horizontal and unsaturated zone in vertical zoningRecharge area in horizontal and seasonal fluctuation zone in vertical zoningRunoff area in horizontal and shallow saturation zone or deep circulation zone in vertical zoningRunoff area in horizontal and stressful saturation zone in vertical zoningDischarge area in horizontal zoning
[C31] length of tunnel (km)<1.01.0~3.03.0~10.010.0~30.0>30.0
[C32] area of disturbed range (m2)<5050~120120~250250~350>350
[C33] construction methodTunnel boring machine methodNew Austrian Tunneling MethodPartial excavation using drilling and blasting method Benching tunneling using drilling and blasting methodFull face excavation using drilling and blasting method
[C34] burial depth of tunnel (m)Extremely bad for water inflowBad for water inflowModerate for water inflowGood for water inflowExtremely good for water inflow
[C35] measures for prevention of groundwater flowing into tunnelComposite lining and pregroutingComposite lining and exterior waterproof (or postgrouting)Composite liningStructural self-waterproofDrainage