Inadequate rock cover

Geofrost provides ground improvement above the rock surface which can be established from the tunnel face or from the ground surface. The soils are frozen to a strong and impermeable temporary supporting structure. By freezing from ground surface the tunnel excavation can continue without stop, either by traditional drilling and blasting or by tunnel bore machine. We install freezing pipes around the whole tunnel, or part of the tunnel circumference, depending on the situation. Often the whole circumference must be frozen when sealing against water ingress or pore pressure reduction. In cases of local support against break in of blocks or poor ground it may be sufficient to freeze a smaller arch, for example above the crown or on one side. Our website