9304506 Muhunthan During an earthquake, the motion of the ground inputs both kinetic and potential energy into a soil mass or structure. The ability of these systems to dissipate this energy when subject to vibration is a key factor in the design of earthquake-resistant systems. Energy principle have traditionally provided methods for the design of earthquake- resistant structures, but for soil dynamics, the approach has been to concentrate on stress-strain based formulations. Thus, this project is motivated to examine the response of soil structures to earthquake loading using energy principles to quantify soil performance up to failure. The objective of this research project is to identify and develop the relationships between relevant energy characteristics in monotonic and cyclic loading leading up to failure and soil liquefaction, and to use the state boundary surface as an energy envelope that provides a unifying link between monotonic and cyclic loading. As part of this development, it is necessary to examine the question of uniqueness of the state boundary surface. The main objectives are: 1. Establish an energy envelope for monotonic soil behavior and its relationship to the state boundary surface. 2. Investigate the hypothesis that liquefaction initiates when the input energy level exceeds the dissipation energy in cyclic loading. 3. Develop a framework to analyze soil failure due to liquefaction, based on energy principles. This is a collaborative research project involving Washington State University and the Georgia Institute of Technology. ***
