Calculating methodology of large base slabs: compressible strata capacity and foundation settlement

Abstract

The paper focuses on determining foundation active zones and calculating foundation settlement which is the question of great scientific and practical interest. According to existing methodologies, researchers apply the theory of homogeneous isotropic linear-deformable medium to determine the deformation of soil foundations. In this study the authors propose to use the theory of soils compression seal and its one-dimensional problem solution to calculate the sediment of large base slabs. To justify this methodology, the authors specify the minimum size of foundation slabs. They analyze the Boussinesq's Formula and prove that compacting pressure is evenly distributed throughout the area of the slab bottom. The researchers delimit concepts of the active zone and the compressible strata. It is assumed that the compressible strata is a part of the active zone. The existing methods on calculating compressible strata capacity introduced by N.A. Tsytovich and K.E. Egorov (SP 22.13330.2016) are also analyzed in the paper. Besides, formulas of determining compressible strata capacity and of calculating slab foundation settlement are presented. Calculation results of this methodology and the method suggested in the existing code specification (CS) are produced and compared. The researches come to the conclusion that, according to CS, compressible strata capacity increases with the increase of foundation space under the same load. This corresponds to the theory of linear-deformable half-space. The authors believe that the size of slab foundation settlement depends only on the compacting pressure capacity (which coincides with the Winkler's hypothesis), and on the properties of foundation soils. The authors assign the application area of the spatial problem solution for calculating foundation settlement.