Sustainability of discontinuously supported slopes in temporary shallow excavations for building construction: a stability analysis procedure

Resumen

Sustainable building construction requires a design process that ensures long-term structural durability and minimizes risks of failure or damage during construction and throughout the structure's service life. One critical aspect of this process is the excavation of simple basements, which often requires discontinuously supported excavation (shielding) when soil stability is compromised, or nearby buildings or infrastructure are at risk. Despite the apparent simplicity of this technique, the lack of a standardized procedure to verify the safety of excavated slopes frequently leads to accidents and damage to adjacent structures. This research introduces a methodology for assessing the safety of discontinuously supported excavations. The proposed method involves a series of calculations based on the Finite Element Method (FEM) to develop a stability chart. Currently, no established approach exists to address this complex three-dimensional problem. The models used are characterized by the slope height and the width between supports. The soil is modeled as elastoplastic, following the Mohr-Coulomb failure criterion, with parameters including the friction angle and the cohesive strength. A comprehensive set of simulations is conducted for various heights, widths, and friction angles to determine the minimum cohesive strength required to achieve a specific safety factor. All results are appropriately non-dimensionalized to generate stability charts, which provide an accessible tool for assessing the stability of discontinuously supported slope configurations with a given width between shields.