Piping and Erosion

During skirt penetration, the water entrapped within the skirt compartments flows out through outlet valves. The acceptable rate of penetration is therefore governed by the capacity of the outlet valves. If the penetration is too fast, an excess water pressure will build up 

Soil pressure on domes at 0.3 m penetration depth for Stratfjord A Condeep structure. (From Hide, O. et al.. Marine Geotech., 3,315-368,1979a. Reprinted with permission. Copyright Taylor Francis Group.) 

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