Upper bound stability analysis of single-layered slurry trenches in clay using the perturbation method

This study systematically analyzed the stability of slurry trenches in clayey soils. The analysis focused on non-homogeneous clays with a linear increase in undrained shear strength. The perturbation procedures based on three-dimensional rigid translational moving elements are established and employed in the analysis. The findings of this study provide lower upper-bound solutions than the existing solutions and demonstrate the potential of the perturbation method in delivering precise upper-bound solutions. The study offers a comprehensive understanding of the factors affecting trench stability, including the dimensions of the trench (width, length, and depth), the properties of the slurry (unit weight and filling level), and the properties of the clay (unit weight, the undrained shear strength at the ground, and undrained strength gradient). The analysis is investigated by considering the dimensionless quantities associated with previous factors. Finally, a novel design equation is presented through nonlinear regression analysis of computed upper-bound solutions.