Estimation of Soil Expansion Force in Static Pipe Bursting: Comparison between Numerical and Analytical Solutions

Abstract

Pull-force estimation is important for the design of static pipe-bursting projects. Among the three components of the pull force, soil expansion force has a significant impact. In this study, a numerical model was employed to determine the soil expansion pressures acting on the expander during pipe bursting. The expansion pressures were used to calculate soil expansion forces, which were then compared to those calculated on the basis of a large-strain analytical cavity expansion solution and those measured from laboratory experiments. Additionally, a parametric study, using numerical modeling and the analytical solution, was conducted to examine the influence of depth of cover on the calculated expansion forces. Typical pipe geometries and soil properties in Edmonton, Alberta, Canada, were used for the parametric study. The results reveal that although the soil expansion force obtained from the analytical solution was higher than that from numerical modeling, the difference decreased when the depth of cover increased. The analytical solution can provide a conservative estimation with a maximum discrepancy of 30%.