A micromechanical model of collapsing quicksand

TL;DR

This paper introduces a micromechanical contact dynamics model that simulates the collapse behavior of quicksand, capturing the physical processes and penetration dynamics of loose granular soils, including a novel 'living quicksand' type.

Contribution

The study develops a modified contact dynamics model specifically tailored to simulate quicksand behavior, including cohesive effects and collapse dynamics, which was not previously modeled in detail.

Findings

Penetration force follows a power law with velocity, with an exponent of 1/2.

The model successfully reproduces the collapse and penetration behavior of loose soil systems.

The approach captures the physical processes underlying quicksand dynamics.

Abstract

The discrete element method constitutes a general class of modeling techniques to simulate the microscopic behavior (i.e. at the particle scale) of granular/soil materials. We present a contact dynamics method, accounting for the cohesive nature of fine powders and soils. A modification of the model adjusted to capture the essential physical processes underlying the dynamics of generation and collapse of loose systems is able to simulate "quicksand" behavior of a collapsing soil material, in particular of a specific type, which we call "living quicksand". We investigate the penetration behavior of an object for varying density of the material. We also investigate the dynamics of the penetration process, by measuring the relation between the driving force and the resulting velocity of the intruder, leading to a "power law" behavior with exponent 1/2, i.e. a quadratic velocity dependence of the drag force on the intruder.