Sink vs. tilt penetration into shaken dry granular matter: the role of foundation

TL;DR

This study investigates how cylindrical objects with different bottom designs sink into shaken dry granular beds, revealing that foundations influence sinking behavior and tilting under strong lateral vibrations, supported by experiments and simulations.

Contribution

It demonstrates that the presence of a foundation causes tilting during sinking in shaken granular media, a behavior confirmed by experiments and numerical simulations.

Findings

Flat-bottom cylinders sink vertically without tilting.

Foundations induce tilting during sinking under strong vibrations.

Numerical simulations accurately reproduce observed behaviors.

Abstract

We study the behavior of cylindrical objects as they sink into a dry granular bed fluidized due to lateral oscillations, in order to shed light on human constructions and other objects. Somewhat unexpectedly, we have found that, within a large range of lateral shaking powers, cylinders with flat bottoms sink vertically, while those with a "foundation" consisting in a shallow ring attached to their bottom, tilt besides sinking. The latter scenario seems to dominate independently from the nature of the foundation when strong enough lateral vibrations are applied. We are able to reproduce the observed behavior by quasi-2D numerical simulations, and the vertical sink dynamics with the help of a Newtonian equation of motion for the intruder.