Dynamic Centrifugal Modeling of a Horizontal Dry Sand Layer

Abstract

The dynamic response of a 10.7 m (35 ft) thick dry sand layer was modeled on the Cambridge University centrifuge at scale factors of 35 and 80. A stack of teflon‐coated aluminum rings and a latex membrane confined a cylindrically shaped sand model that had a height‐to‐diameter ratio equal to 1. During the scaled sinusoidal base shaking, electronic transducers measured accelerations, transient horizontal displacements and surface settlements. While sensors measuring accelerations and surface settlements worked well, the DC LVDT's used to measure transient horizontal displacements were influenced by frequency‐dependent behavior. Measured results were used to evaluate scaling laws governing dynamic centrifugal modeling and to test for consistency with results of numerical methods and laboratory tests reported in the literature. The results of the test program indicate that a simple sand layer can be effectively modeled aboard a centrifuge and that horizontal accelerations, cyclic shear strains, and settlements follow the scaling laws that govern dynamic centrifugal modeling.