Settlement Computation of Homogeneous Base

Purpose of reseach. This article proposes the development of a new methodology for determining the settlement of a homogeneous foundation base on the basis of the layer-by-layer summation method, which reduces the amount of calculations performed.

Methods. The boundary of the compressible stratum can be determined graphically from the condition that the additional stresses are equal to half the natural stresses. Knowing the value of the depth of the compressible stratum, we can determine the total value of the coefficients included in the well-known formula for calculating the settlement of the base by the method of layer-by-layer summation. Having determined the value of the specified coefficient in the layer located directly below the base of the foundation, we introduce the coefficient Kα, which reflects the proportion of sediment in the layer under consideration.

Results. The application of the developed coefficient Kα allows determining the base settlement by calculating the deformations of one soil layer located directly below the base of the foundation, which greatly simplifies the design of underground structures. As an example, we consider a foundation, the average pressure under the sole of which is 1200 kPa, the laying depth d = 2 m, the base is homogeneous with a deformation modulus of 20 MPa and a specific gravity of γ = 18 kN / m3. The settlement of the building-basement system was calculated by the method of layer-bylayer summation and the critical analysis of the results was performed. When calculating precipitation by the method of layer-by-layer summation according to the known formulas given in SP 22.13330. 2016 “Foundations of buildings and structures”, it was obtained a draft value of 9 cm. When calculating the base deformations according to the proposed method, the boundary of the compressible thickness Hc = 5.7 m was graphically determined. The coefficient value was 0.203, and the draft was 9 cm.

Conclusion. The settlement values determined in accordance with current regulatory documents and the developed methodology are the same, which allows us to conclude that the proposed method has a sufficient degree of reliability and can significantly facilitate the process of determining the deformations of the base of buildings and structures.

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