Numerical Simulations of a Strip Footing on the Soil Slope with a Buried Pipe Using the Material Point Method

Given the prevalence of such scenarios worldwide, it is of the utmost importance for geotechnical practitioners to understand the behavior of a strip footing located over a pipe buried within a slope. This study focuses on investigating the failure mechanism of the footing-on-slope system, and a series of numerical simulations have been conducted using the material point method. The accuracy of the numerical model has been verified through comparisons with the results of model tests in the literature. The influence of the setback distance of the footing, burial depth of the pipe, and slope angle on the bearing capacity and failure modes has been analyzed in detail. The results demonstrate that the presence of the pipe reduces the bearing capacity of the strip footing. Meanwhile, the variations in the setback distance and slope angle may cause a reduction in the ultimate bearing capacity by 76% and 75%, respectively. The failure mode of the footing-on-slope system is determined by the pipe location, setback distance of the footing, and slope geometry. For shallow burial conditions, the pipe–soil interface can accelerate the development of failure surfaces. From the perspective of Mohr's circle, the principal stress deflects due to the applied pressure, resulting in different failure surface shapes. The schematic diagram of the failure mode can be used to predict the failure mechanism of the footing-on-slope system, thereby helping in the safe design of slopes with buried pipes.