Seismic Analysis of a Large Oil Tank With Floating Roof

Seismic qualification of the large oil tanks requires consideration of a lot of specific failure modes. One of them is the failure induced by dynamic behaviour of the floating roofs or pontoons: a collision between floating steel roof and tank wall during an earthquake can lead to the post crash fire with severe system fault. Seismic behaviour of a 50000 m³ tank with floating pontoon has been investigated in a numeric study. Seismic safety limits of the considered tank including floating roof movement are presented. A validation study using numerical experiments of the tank with floating pontoon has been performed in order to verify the analytical approach. An influence of the tank anchorage on the tank seismic behaviour and specific failure modes connected with tank bottom uplift has been also investigated.