Water stopping of water ingress into construction Shafts
There are a number of methods for the construction of shafts, the most common being: The use of sheet piles, diaphragm walls or bored piles to construct a cylindrical, square, or rectangular braced shaft. The use of segmental lining installed by underpinning or caisson sunk to form a circular shaft.
Often the shafts maximum depth will be below the local water table. If gaps are present in the shaft lining, water will ingress into the shaft often at multiple points. The volume and frequency of the water ingress will vary dependent on (i) seasonal raise and fall of the local water table, (ii) installation/placement accuracy of the shaft lining during construction, and (iii) the type of geology surrounding the shaft.
Sometimes consideration are made to waterproof the shaft. This can be achieved by the use of sealing strips, water bar profiles to seal and ensure the tight fit between the elements used in the shaft wall construction.
Equally, spray applied solutions may be considered, such as shotcrete or specialty spray applied membranes.
In any case, if water ingress does occur in a shaft there are methods with which to stop the water stop the water ingress, permanently or temporarily.
Those methods can be utilized as such:
1. Temporary solutions for stopping of water seepage into shafts
2. Permanent solutions for stopping of low to medium volume/pressure water ingress into shafts
3. Permanent solutions for stopping of heavy volume/pressure water ingress into shafts