Formation of stress-strain state in the founda-tions of grain drying complexes when chang-ing soil parameters

Abstract

The work of the pile foundation of the grain drying complex when changing the parameters of soils determined by laboratory and field methods has been studied. Two variants of calculations with the help of numerical modeling by the finite element method were carried out: 1) using the characteristics of soils, which were determined by laboratory methods; 2) using the characteristics of soils, which are determined by field methods. The stress-strain state of the foundation structures of the grain drying complex is analyzed in the work, namely: redistribution of forces in the piles, subsidence of the foundation structures, bending moments and the area of working reinforcement in the foundation slab.
 The paper emphasizes the use of pile foundations for grain drying complexes due to the emergence of many negative factors in the installation of slab foundations. The main ones are: low soil indicators in the upper zone of the soil massif; construction of several silos next to each other, which determines their interaction; uneven loading - unloading of silos; the choice of calculation method, which correctly describes the parameters of the soil and the stages of loading and unloading of silos. The paper also presents problematic issues in the design of pile foundations for grain dryers. The results of the study of the formation of the stress-strain state of the foundation structures at different soil parameters are presented.
 The study was conducted in clay soils of solid and semi-solid consistency. The pile foundation is based on hard sandy loams and soft-plastic loams.
 The paper shows that with increasing soil parameters of the base decreases the subsidence of the foundation slab. The redistribution of forces between the piles has a similar character, but due to the increased rigidity of the base, the foundation plate transfers the load to the base, so almost all piles are unloaded within 5… 10%. At the same time bending moments in the base plate are reduced that demands reduction of reinforcement by working armature. This allows you to design reliable and economical solutions for pile foundations of grain dryers.