Duxseal boundary effects on static and dynamic responses in numerical models validated against small-amplitude dynamic centrifuge tests

Abstract

The effect of natural or man-made dynamic events on people is an important topic, in particular disturbance caused by construction activities or infrastructure systems. Centrifuge modelling has provided valuable insights and data for understanding the propagation of waves within the ground, as well as their interaction with surface and buried structures. Wave absorbing materials, such as Duxseal, have been widely employed within dynamic centrifuge tests due to their ability to reduce the impact of reflected waves at container boundaries. Despite their beneficial wave absorbing characteristics, the use of these materials at the walls of centrifuge model containers may also have negative consequences, potentially altering the actual dynamic response of the soil due to the compressibility of the wave absorbing materials. The extent of these effects and their contributing parameters (e.g. wave absorbing material properties, location, and thickness) is an area of uncertainty, which becomes problematic when attempting to validate analytical or numerical methods using the obtained centrifuge test data. With the aim of advancing the understanding of the effects of wave absorbing materials on dynamic centrifuge tests and providing guidance on how these effects can be appropriately considered within numerical models, this paper presents results from geotechnical centrifuge tests on ground-borne vibrations generated from the vertical oscillation of a single pile in sand with Duxseal boundaries, with a parametric study performed to calibrate a corresponding numerical model based on the results obtained from the centrifuge tests. The calibrated numerical model is then employed to extend the knowledge obtained from the centrifuge tests, and to explore the effects of Duxseal on physical modelling results. The presence of Duxseal is shown to affect the initial earth pressure coefficient $K_0$, in particular near the ground surface. The insights presented will benefit the analysis of future dynamic centrifuge tests involving wave-absorbing boundaries, in particular where the impact of this boundary on test outcomes is important (e.g. where the focus of analysis relates to a near-surface buried structure) and where numerical modelling is used to replicate centrifuge tests.