Modeling suffusion of ideally gap‐graded soil

Abstract

A novel framework for describing suffusion in cohesionless soil, incorporating ideally gap-graded soil, is presented in this paper. The key assumption of the proposed simulation is that an erodible particle flow is induced primarily by drag force. The multiphase flow simulation for seepage-soil particle flow phenomena is conducted based on the proposed framework. The validity of the proposed method is checked through a simulation of past laboratory experiments, in which the variation in grain size distributions is grasped by a sieve analysis. The primary results show cumulative fines loss; therefore, a comparison of the cumulative fines loss is mainly discussed in this research. In addition, a discussion is given on the two different parameters affecting the erosion behavior, namely the 𝑝−𝑣𝑎𝑙𝑢𝑒 in the tortuosity function, 𝑇(∅) , and the clogging relaxation time, 𝛽𝑐𝑙𝑜𝑔 . The tortuosity is the ratio of the actual flow path and the distance between its ends, while clogging relaxation time is the parameter that considers the particle flow through the bottleneck. The results show that the numerical simulation provides a good correlation with the experiment, while the 𝑝−𝑣𝑎𝑙𝑢𝑒 is 3 which is the highest value for a geo-material. Moreover, the simulation results of the cumulative fines loss for each particle size also confirm that smaller particles will be fully eroded earlier than larger ones, and that larger particles will slowly become detached from the soil mass.