Sink versus tilt penetration into shaken dry granular matter: The role of the foundation

TL;DR

This study investigates how cylindrical objects sink into shaken dry granular beds, revealing that foundation design influences sinking behavior and tilting, with implications for understanding structural responses during earthquakes.

Contribution

The paper demonstrates that foundation shape affects sinking and tilting in shaken granular media, supported by experiments and simulations, providing insights into earthquake-related structural stability.

Findings

Flat-bottom cylinders sink vertically under shaking.

Foundation rings induce tilting during sinking.

Aspect ratio influences sinking dynamics.

Abstract

We study the behavior of cylindrical objects as they sink into a drygranular bed fluidized due to lateral oscillations. 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 ashallow ring attached to their bottom, tilt besides sinking. Thelatter scenario seems to dominate independently from the nature ofthe foundation when strong enough lateral vibrations are applied. Weare able to explain the observed behavior by quasi-2D numericalsimulations, which also demonstrate the influence of the intruder's aspect ratio. The vertical sink dynamics is explained with the help of a Newtonian equation of motion for the intruder. Our findings may shed light on the behavior of buildings and other man-made constructions during earthquakes.