GGU-RETAIN: Utilisation factor (hydraulic heave) using partial safety factors

Using the partial safety factor concept the following must be verified:

• S'_k = characteristic flow force on the percolated soil mass

• γ_H = partial factor for the flow force in favourable or unfavourable subsoil in the
  HYD (EC 7) limit state

• G'_k = characteristic dead load of the buoyant percolated soil mass

• γ_g,stb = partial factor for stabilising permanent actions in the
  HYD (EC 7) limit state

• Layer 1 (i = 1) is the uppermost layer

The so-called utilisation factor µ can also be calculated from this relationship.

• µ_N = utilisation factor of layer N

Utilisation factors ≤ 1.0 mean that sufficient safety is given.