Numerical simulation and parametric analysis of multi-anchor walls using the finite element method

The paper describes the first reported attempt to numerically simulate the performance of full-scale steel multi-anchor reinforced soil walls (MAWs) during construction using a commercially available two-dimensional finite element method (FEM) model. The numerical simulation results are compared to the measurements taken from three 6 m-high MAW structures that were constructed under carefully controlled in-door laboratory conditions. The walls were nominally identical but constructed with three different sandy soils varying with respect to soil stiffness and shear strength. Earth pressures and anchor loads were monitored during construction and in-situ anchor pullout tests were also performed. Numerical predictions are judged to be in reasonable agreement with most physical measurements. A novel technique was the use of in-situ anchor plate pullout test results to back-calculate initial elastic modulus values for the hyperbolic constitutive soil model used in the study. The physical and numerical results are extended by considering a wider range of wall parameters (initial soil stiffness, shear strength, anchor length and wall height) using the same FEM model. The results of this parametric analysis provide further insight into the influence of the magnitude of different input parameters including wall height on wall performance. The main objective of this study was to generate a satisfactory definition of end-of-construction conditions. The paper also reports the results of a series of case studies that can be used by design engineers to benchmark-test FEM models proposed for MAW projects that are too complicated for analysis and design using conventional simple strength-based internal stability methods and where performance-based design requires estimates of wall deformations.