Development of a novel cylindrical cam shaking table for geotechnical centrifuge modelling

Abstract

The use of dynamic centrifuge modelling has substantially risen over the years for investigating failure mechanisms, studying the physics-based mechanics of soil structure systems, and validating numerical tools. Nevertheless, the primary issues associated with the use of servo-hydraulic actuators (presently the prevailing shaking table for a geotechnical centrifuge) are their exorbitant expense, intricate operation, and shaking control. This paper describes the development of a novel cylindrical cam shaker for the newly installed Mark III geotechnical centrifuge facility at Tokyo City University. The cylindrical cam mechanism is activated once the desired voltage is applied via the electrical slip rings. The rotation of the cylindrical cam is translated into the linear motion of the follower plate which then moves the shaker linearly back and forth. A stepwise procedure is developed to determine the voltage required to drive the shaker and achieve the desired earthquake characteristics for a given payload mass and centrifugal acceleration. The performance of the shaker was systematically assessed through a series of dynamic centrifuge experiments at different centrifugal accelerations and payload masses. Finally, the excellent capabilities of the developed mechanical shaker in terms of the repeatability of the base motions were demonstrated using a model example.