Particle Flow Code Method-Based Meso-scale Identification for Seepage Failure of Soil Levee

Abstract

The long-term action of internal and external factors leads constantly to seepage failures of soil levee engineering such as soil flow failure and piping failure. It is very disadvantageous to the service safety of levee engineering. Most of disastrous accidents are induced directly or indirectly by seepage. It has been known that the water–soil interaction with particle migration determines the occurrence and development of seepage failure. In this paper, a particle flow code (PFC)-based approach is introduced to implement the numerical simulation for seepage behavior in soil levee and investigate the meso-scale seepage failures. Firstly, according to the granular properties and particle migration characteristics of soil levee, an implementation process is presented to construct the meso-scale soil particle model and analyze the levee failure. Then, considering the coupling action of soil and water, a numerical method combining PFC with computation fluid dynamics is developed to simulate the seepage failure of soil levee. The corresponding criteria on seepage failures of soil levee are given. Lastly, one actual levee engineering is taken as an example. The movements of soil and water in the soil flow and piping processes are investigated with meso-scale soil particle model of selected levee. The meso-scale mechanism of seepage failures is analyzed, and the seepage stability is evaluated. It is indicated that the proposed PFC-based approach can fulfill the real-time observation for the movement status of soil particles and water during seepage failure of soil levee. The seepage stability identification with the introduced meso-scale criteria shows good agreement with the experimental result.