Finite element analysis of a deep excavation supported using a secant pile wall: a case study

Abstract

Accurate finite element modeling (FEM) of deep excavations is a difficult task due to the lack of availability of details about the soil strata below ground level. This study proposes a method to select the appropriate parameters and correct modeling procedures in the FEM of deep excavation using measured field test data using two-dimensional analysis. Some studies indicate that the elastic modulus (E50) of soil can be increased by several times to obtain the unloading-reloading modulus (Eur) of the soil. The back analysis technique was used to calibrate the elastic modulus of the soil by comparing the lateral wall deformation profile obtained from the FEM analysis with the inclinometer readings acquired from the excavation site. The numerical model was validated using the behavior of a retaining wall at various excavation depths and analyzed through numerical simulations. Prop forces obtained from the numerical analysis were compared with those obtained from different empirical methods commonly used to estimate prop forces on multi-propped retaining structures. The study highlights that the elastic modulus of the soil can be increased between 2 and 4 times to obtain the unloading-reloading modulus of the soil.