Centrifuge modeling is a useful technique for studying a wide variety of geotechnical earthquake engineering problems. Centrifuge models of geotechnical structures can be carefully instrumented and subjected to extreme - that is, design level - loading conditions in a repeatable and realistic manner. Specifically, they can be subjected to simulated large earthquakes. This has the potential to provide data that are extremely difficult - and rarely possible - to obtain from full-scale geotechnical structures subjected to naturally occurring large earthquakes. This earthquake simulation capability is already available at five academic institutions in the U.S., but to date only small geotechnical models can be subjected to simulated earthquakes. Researchers at the Rensselaer Polytechnic Institute are currently designing a shaker which will permit the use of intermediate-sized models on the intermediate- sized centrifuge at that institution. This action is to support design studies for an earthquake simulator for the large geotechnical centrifuge at the University of California at Davis. This simulator would have the capacity to subject large models to simulated earthquakes. The unique feature of this centrifuge is its bucket size (6 feet by 7 feet in plan), which permits experiments to be conducted on large models. The large models that can be tested permit: (1) use of more instrumentation while minimizing the influence of instrumentation on model behavior; (2) fine details can be included in the model; and (3) the possibility of conducting tests at lower scale factors to minimize scale effects and to extend the range of modeling of models (a technique to verify that small-scale models are capable of modeling accurately the full-scale behavior). This design study is monitored by an Oversight Committee composed of experts from other institutions. The Oversight Committee will undertake separate design studies; which, when combined with those supported by this award, are expected to address effectively the extremely challenging problems associated with the design of a large centrifuge earthquake simulation facility.
