This action is to support the upgrading of the control system for a sophisticated soil testing apparatus in the Civil Engineering Department of the University of California at Los Angeles . This apparatus is used for teaching as well as for research. The upgraded control system provides the precision of testing and the resulting accuracy of data measurement that is needed in the development of models for the mechanical response of soils under conditions of cyclic loading. These analytical and computational models are being developed from experimental evidence for the behavior of cohesionless soils during large three-dimensional cyclic stress changes, such as those that soil masses experience during the strong ground shaking induced by large earthquakes. The results from the upgraded soil testing apparatus provide the basis for improvements in earthquake hazard mitigation.
