MPM Investigation of Soil Fluidization Mechanism Around a Pressurized Leaking Pipe
Keywords: Soil fluidization, Material Point Mrthod, pipe leakage
TL;DR: This paper uses the advanced two-phase double-point material point method (MPM) technique to capture the initiation and evolution of soil fluidization induced by a leaking pipe.
Abstract: Leakage in underground buried pipes can trigger soil fluidization leading to severe ground failure. Soil fluidization refers to the transformation of soil particles from a solid-like to a liquid-like state, which can result in the collapse of the underlying ground and damage to buried utilities. In this research, an advanced two-phase double-point material point method (MPM) is employed to investigate the process of soil fluidization around a leaking pressurized water pipe buried in fully saturated soil. Additionally, in/outflow boundary conditions (BCs) are implemented to prescribe constant velocity inflow of material points into the region. The MPM model is utilized to identify the inflow water velocity leading to the initiation and development of soil fluidization around the leaking pipe based on the changes in soil porosity and expansion of the soil bed. The research demonstrates that the MPM findings are consistent with previously published experimental studies. Parametric analyses are conducted to explore the effect of various factors, such as orifice size, bed height, and soil porosity on soil-leakage interaction. The results indicate that as the orifice size and soil porosity increase, the inflow velocity needed for the initiation and progression of fluidization decreases. Conversely, greater bed height enhances the soil bed's resistance to fluidization. The double-point MPM formulation is demonstrated to be a valuable and promising approach for examining the soil-water interaction caused by a pipe leak. The model developed in this research has the potential to serve as a predictive tool for assessing the extent and advancement of the fluidization zone, as well as for identifying the critical conditions that result in ground failure. Such a tool would be of considerable importance for asset managers responsible for the maintenance of underground pipes and the stability of the supporting ground.
Submission Number: 16
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