Influence of leakage direction and pipe depth on the soil fluidisation using the MPM




Influence of leakage direction and pipe depth on the soil fluidisation using the MPM


Soil fluidisation induced by a defective pressurised pipe could generate an underground cavity leading to severe ground collapse. Pipe leakage may fluidise the surrounding soil if sufficient leakage is presented. This study provides insights into the significance of the fluidisation mechanism triggered by a defective pressurised pipe and identifies the critical state that causes the ground subsidence. A two-phase double-point Material Point Method (MPM) model is developed to simulate the behaviour of a soil bed subjected to leakage from a buried pressurised pipe. Additionally, in/outflow boundary conditions (BCs) are applied to prescribe constant velocity inflow of material points into the region. The MPM model is used to study the soil fluidisation mechanism, which involves a change in soil porosity and expansion of the soil bed. Parametric analyses are conducted to investigate the effect of the leakage direction and the buried depth of the pipe on soil-leakage interaction. The results indicate that lateral leakage requires a higher leakage velocity to trigger soil fluidisation than upward leakage. The shallower the pipe depth, the lower the inflow velocity required for the onset and development of fluidisation, but the greater the ground displacement. 



Ali Monzer; Asaad Faramarzi; A. Yerro; D. N. Chapman


10th European Conference on Numerical Methods in Geotechnical Engineering (NUMGE2023)



2. Finite element, finite difference, discrete element, material point and other methods



https://doi.org/10.53243/NUMGE2023-50