Base Isolation Benefits of 3‐D Rocking and Uplift. II: Numerical Example

Abstract

Block objects, standing on a shaking foundation, will tend to rock and possibly uplift. Rocking of buildings in earthquakes are of particular interest because human lives and high costs are at stake. Most previous studies on rocking are limited to two‐dimensional motion for simplicity. The theory of a new model, which includes three‐dimensional rocking, rolling, and uplift of a rigid cylinder subjected to ground motion, is put forth in the companion paper. This paper describes a numerical example of the new model. Computer simulations show that 3‐D motion is significant under earthquake‐like excitations. When rocking is predominantly 2‐D, high spikes in accelerations and internal stresses are produced in the structure. The model that allows uplift is compared with the model that does not allow uplift. It is determined that restricting uplift can introduce higher stresses and accelerations inside the structure.