Advanced 3D finite element limit analysis for assessing blowout stability in water main bursts

The increasing occurrence of sinkholes caused by water main bursts has attracted significant research attention in recent years. This study addresses the gap in evaluating soil blowout stability resulting from water main failures by investigating the three-dimensional stability of blowouts with circular, hemispherical, and spherical openings. Advanced finite element limit analysis (FELA) combined with adaptive meshing is employed to analyze critical factors, including soil cover depth, surcharge pressure, and internal water pressure, that contribute to blowout failure. In addition, dimensionless ratios are used throughout the paper to assess the influence of these factors. Numerical findings are rigorously validated, ensuring reliability and accuracy. Practical design charts are provided to accommodate a wide range of design scenarios, offering valuable guidance for engineers. This study introduces a pioneering sinkhole simulation methodology, leading to the understanding of three-dimensional blowout stability mechanisms.