Two-Dimensional Consolidation of Raft Foundation Subsoil Considering Soil Permeability Anisotropy

This paper evaluates the accuracy of Terzaghi’s one-dimensional consolidation theory for time-dependent settlement prediction of large-area raft foundations. At the raft foundation significant size and significant anisotropy of subsoil filtration properties (k_x/k_y>>1), the consolidation process acquires a manifested two-dimensional character due to pore water lateral outflow outside the loaded area. A parametric finite element study was carried out using Plaxis 2D for an axisymmetric model of the raft foundation on a clay stratum. The raft radius (R=10, 20, 30 m), clay layer thickness (H=5, 10, 20 m), and permeability anisotropy ratio (k_x/k_y=1, 2, 5, 10) were varied. It was found that at low R/H ratios (R/H = 0.5), increasing the anisotropy coefficient from 1 to 10 accelerates consolidation by the factor of 2.6, whereas at R/H=6, the effect of anisotropy is negligible. The limits of applicability of the one-dimensional approach were established as a function of R/H and permeability anisotropy.

A.Z. TER-MARTIROSYAN, Doctor of Sciences (Engineering), Associate Professor (This email address is being protected from spambots. You need JavaScript enabled to view it.),
V.V. RUD, Candidate of Sciences (Engineering) (This email address is being protected from spambots. You need JavaScript enabled to view it.),
P.V. SHISHKINA, Student (This email address is being protected from spambots. You need JavaScript enabled to view it.),
A.M. VAROSYAN, Student (This email address is being protected from spambots. You need JavaScript enabled to view it.)

National Research Moscow State University of Civil Engineering (26, Yaroslavskoe Highway, Moscow, 129337, Russian Federation)

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