Analysis at the ultimate limit state of a R/C slab supporting desiccated-sludge silos

A rather thin R/C slab resting on six square columns is studied in this paper, under the loads due to two large silos, each containing roughly 60 tons of desiccated sludge. Limit analysis according to the Yield-Line Method is applied to identify the weakest resistant mechanism among the several global and local mechanisms, that are kinematically admissible for the given restraints, loads and cut-outs of the slab. This application demonstrates once more how powerful and handy the Yield-Line Method is, in a case where the setting is particularly favorable to the use of this flexural approach, since the membrane forces developed along the boundary are negligible and the ultimate behavior of the slab is controlled by bending.