Foundation slabs bending model with variable stiffness ratio rested on elastic foundation

Abstract

The study addresses the problem of designing slabs with variable stiffness to meet such requirements as reducing material consumption, ensuring reliability, durability and cost-effectiveness. The paper offers a solution of the spatial task of contact interaction of orthotropic slabs with elastic foundations. The system of integral−differential equations, which the task is reduced to, is solved numerically by a combination of the finite-difference method and the boundary elements method. The finite-differential scheme is considered to be a shock-capturing type, characterised by the fact that the boundaries of the areas with different mechanical properties are not explicitly highlighted, and in grid nodes the smoothing principle was applied. As the soil foundation models, the elastic linear-strain space and elastically compressional wedge were used. The contact pressure distributions, bending moments and deflections of rectangular slabs of variable stiffness fully adjacent to the base were found. The impact on slabs’ stress−strain behaviour, the degree of soil thickness uneven compressibility and its material orthotropic properties change were analysed. The developed method effectively simulates behaviour of slab-based foundation structures in complex geological conditions where it is necessary to take into account the heterogeneity of soil thickness compressed by a building or a facility.