Bases and foundations for grain cylindrical silos

Abstract

The creation of grain storage and processing enterprises with thin-walled metal silos in Ukraine, in addition to the domestic manufacturers, involves the foreign ones, whose design preconditions for the metal silos structural engineering and designing are not generally available. During the silos operation, quite often the significant foundations settlements and tilts, which were not foreseen in design documents, occur. The features of the silos bases and foundations designing from metal structures are not sufficiently reflected in the current regulatory documents. Based on the calculations, the method of equivalent settlement layer in the cylindrical silo SMVU 220 foundations versions shows that in the case of a ring foundation, if the silo is not loaded with grain, its body floor disengages from the foundation. The geometric characteristics analysis shows that a circular foundation contributes to the foundation and silo body tilt reduction by 1.3 times compared to the ring foundation, and depending on the soil conditions the reduction can be even more tangible. The SMVU 220 silo foundation settlement calculation shows that, if a soft loam is present in the base, it is necessary to take measures to increase the foundation and soils rigidity with an analysis of the nearby silos mutual influence and the foundations and base joint work. The geological engineering surveys should include the mandatory laboratory tests of a soil deformation module with cyclic loading and dynamic impacts being taken into account. The foundations for cylindrical silos should be designed on a circular plate with the design strengthening of hoop reinforcement in the foundation upper zone and calculated as a "silo body - foundation - base" spatial system. The silo designs shall specify the permissible silo settlements and tilts, as well as the mode of silo initial operational loading and unloading.