Comparison of Coupled and Uncoupled Consolidation Equations Using Finite Element Method in Plane-Strain Condition
Abstract: In the current
paper, the consolidation settlement of a strip footing over a finite layer of
saturated soil has been studied using the finite element method. In Biot’s
coupled consolidation equations, the soil deformation and excess pore pressure
are determined simultaneously in every time step which refers to the
hydro-mechanical coupling. By considering a constant total stress throughout
the time and by assuming that volume strain is a function of isotropic
effective stress, uncoupled consolidation equations can be obtained using
coupled consolidation equations. In these uncoupled equations, excess pore
pressure and deformation are determined separately. In this approach, the
excess pore pressure can be identified in the first stage. Using the calculated
excess pore pressure, the soil deformation is determined through effective
stress-strain analyses. A computer code was developed based on coupled and
uncoupled equations that are capable of performing consolidation analyses. To
verify the accuracy of these analyses, the obtained results have been compared
with the precise solution of Terzaghi’s one-dimensional consolidation theory.
The capability of these two approaches in estimation of pore water pressure and
settlement and to show Mandel-Crayer’s effect in soil consolidation is
discussed. Then, the necessity of utilizing coupled analyses for evaluating
soil consolidation analysis was investigated by comparing the coupled and
uncoupled analyses results.
Keywords: Coupled
Consolidation Analysis; Uncoupled Consolidation Analysis; Finite Element
Method; Strip Footing; Excess Pore Pressure
Author: Mohamadtaqi Baqersad,
Abbas Eslami Haghighat, Mohammadali Rowshanzamir, Hamid Mortazavi Bak
Journal Code: jptsipilgg160045
