The improvement of the slab-ring foundation design with an under-silo gallery of a cylindrical steel silo on the grounds of the computer simulation results and those of field observations

Abstract

Abstract Over the last two decades, steel silos have become quite common in the agro-industrial complex of Ukraine and replaced the reinforced concrete silos due to their more economical design. An urgent problem of the steel silos design is an insufficient bearing capacity of the base and its excessive deformability. For a newly built silo, the vertical settlement of the base and foundation was monitored with geodetic instruments. The absolute deformations of the monolithic reinforced concrete foundation of the silo were measured. A three-dimensional finite-element model of a silo, a foundation, and a base was developed using computer simulation methods. When simulating the behavior of the foundation concrete, the non-linear deformation-force theory of reinforced concrete was used. The basis of the silo is layered and it is composed of settlement soils that do not have sufficient bearing capacity and cause an excessive settlement. Therefore, a ring foundation is provided on a soil base reinforced with soil-cement elements under the perimeter wall of the foundation. The results of numerical simulations and field measurements of vertical settlements and stresses in the concrete of a silo foundation were compared. The difference in vertical subsidence was 60%. The efficiency of the hinged joint of the plate connecting with the perimeter wall has been proven by distribution of contact stresses under the sole of the foundation. In further design practice, it is recommended to use a hinged joint for connecting a slab with a perimeter wall due to the operational reliability of silos.