The Fire tank in Seismic zone is considered to be in category III or IV depending on the case. It is therefore subject to the calculation codes. The impact on the structure of the tank due to seismic action is very important.
The tanks consist of hulls assembled together by bolting.
Eurocodes distinguish 2 types of tanks:
- so-called flexible tanks (metallic coating)
- rigid tanks (concrete coating)
The hulls of the (flexible) metal tanks are so-called thin elements, therefore subjected to very severe stresses induced by the oscillating water mass:
- The resulting forces are very significant at each shell of the tank
- A buckling check of each shell is performed according to the calculation codes
- The shells of the tank are checked under induced hydrodynamic actions
Load lowering on the tank support floor
Apart from the weight of the tank's own water mass, the seismic action generates hydrodynamic pressures on the bottom of the tank. Force that must be applied to the hydrostatic pressure.
Each work is studied on a case-by-case basis: calculation of the forces on the anchors,...
A GC guide plan for the design of the base is communicated to the customer taking into account all the distributions of loads described above.