Possibilities and Limitations of ALE Large Deformations Analyses in Geotechnical Engineering

A number of geotechnical engineering problems involve large deformations in the soil. While small deformation geotechnical problems can be adequately analyzed by means of conventional Lagrangian FEM, such an approach exhibits considerable shortcomings when the soil undergoes significant deformation. Hence methods have been developed which overcome these shortcomings. Among the methods using a computational mesh, the most promising approaches include the ALE methods: Coupled Eulerian-Lagrangian (CEL) method, the Simplified or Single-Material Arbitrary Lagrangian-Eulerian (SALE) method, and the Multi-Material Arbitrary Lagrangian-Eulerian (MMALE) method. In this contribution the possible advantages and limitations of ALE in comparison to other numerical approaches are presented. The performance of ALE methods is evaluated by means of two application examples. First the vibratory driven installation of open-ended tubular steel piles in sand is modeled and local large deformation due to initial pile imperfections and soil heterogeneity is analyzed. Second the sand column collapse problem is simulated using different modeling approaches and soil models as well. Simulation results assess the feasibility of ALE methods in geotechnical large deformation problems. It can be concluded that the ALE method could be considered as a promising framework for solving complex large deformation problems in geotechnical engineering.