Here at Franklin Hodge, we have a long experience in the design and installation of tanks in earthquake (seismic) prone areas of the world. As an example of a typical project carried out by our design, contracts and installation teams, some photographs can be seen below of a project that has recently been completed in a region of Southern Europe that is classified as a zone of seismic activity.
In this case, the tank featured a 9.17m diameter by 6.07m high, galvanised steel Factory Mutual* approved Firestore®. Specially designed and approved holding down bolts and anchors have been provided around the tank base perimeter, as can be seen in the photographs. In the event of an earthquake, the water stored in the tank will be ‘accelerated’ as a wave, through the seismic ‘shock’. This wave will then move back and forth within the tank, creating uneven or asymmetric loads on the tank shell. For a tank that is not adequately designed for this effect and in particular that is not anchored properly, the effect would be to tear it from its foundations. Properly designed foundation anchors, as well as a strengthened tank shell, appropriate for the anticipated seismic loads likely to be encountered, will minimise the damaging effect of the ‘accelerated’ stored water.
*Note: We offer a range of fire water storage tanks designed and approved by Factory Mutual Approvals (part of Factory Mutual Global Group Insurance). Design approval includes specific tank sizes and capacities for a range of seismic ‘zones’, as classified by Factory Mutual.