Tunnel Waterproofing Systems
The choice of tunnel waterproofing system is reliant on a number of factors
- the type and construction of the tunnel.
- expected exposure to water in the location.
- Above water table or below
Such tunnels through rock or other strata may only have to cope with seepage through the rock. Where there is no hydrostatic pressure present, and ground water level below the tunnel footing. Tunnels waterproofing in such tunnels has waterproofing applied only to the top and sides.
Tunnels constructed in loose rock, below the water table, under a river on the ocean floor (eg Sydney Harbour Tunnel), or where springs and water streams are found running through the strata. These tunnel construction conditions, mean the tunnel waterproofing membrane requirements are such that it is necessary to fully wrap the tunnel with waterproofing material which is designed to withstand the expected hydrostatic pressure.