Finite element simulations of seismic effects on retaining walls with liquefiable backfills
Dewoolkar, MM and Chan, AHC and Ko, H-Y and Pak, RYS, Finite element simulations of seismic effects on retaining walls with liquefiable backfills, International Journal for Numerical and Analytical Methods in Geomechanics, 33, (6) pp. 791-816. ISSN 0363-9061 (2009) [Refereed Article]
Finite element simulations of two centrifuge tests on the same cantilever retaining wall model holding
liquefiable backfill were conducted using the Biot formulation-based program DIANA–SWANDYNE II.
To demonstrate the effects due to different pore fluids in seismic centrifuge experiments, water was used
as the pore fluid in one experiment whereas a substitute pore fluid was used in the second experiment.
The cantilever wall model parameters were determined by comparing simulations with measurements
from free-vibration tests performed on the model wall without backfill. The initial stress conditions for
dynamic analysis for the soil backfill were obtained by simulating static loads on the retaining wall from
the soil backfill. Level-ground centrifuge model results were used to select the parameters of the Pastor–
Zienkiewicz mark III constitutive model used in the dynamic simulations of the soil. The effects due
to different pore fluids were captured well by the simulations. The magnitudes of excess pore pressures
in the soil, lateral thrust and its line of action on the wall, and wall bending strains, deflections, and
accelerations were predicted well. Predictions of settlements and accelerations in the backfill were less
satisfactory. Relatively high levels of Rayleigh damping were needed to be used in the retaining wall
simulations in order to obtain numerically stable results, which is one of the shortcomings of the model.
The procedure may be used for engineering purpose dealing with seismic analysis of flexible retaining
walls where lateral pressures, bending strains and deflections in the wall are typically of importance.