We have been developing a computer code for the prediction of the onset of Liquefaction from Seismic shaking. The code is based on early developments by Biot and more recent ones by De Boer and Ehlers. Some of the features of the code were originally developed at the University of Colorado at Boulder, Abifadel and Sture. Results of the code performance with Closed Form Elastic Solutions have been presented at the 11th Engineering Mechanics Conference, ASCE, Fort Lauderdale, Florida, May, 1996. The Mechanics of Granular Materials Behavior of Granular Materials Under Low Effective Stresses and Reduced Gravity Environment View image of MGM Experiment at 0.007 psi Effective Confining Pressure, Astronaut Jay Apt View image of MGM Experiment at 0.007 psi Effective Confining Pressure, Astronaut Carl Walz Granular materials are a form of matter that we encounter every day, yet we often fail to appreciate their many faces in nature.
Sand is an excellent example.
On an average day at the beach, we can build a sandcastle, a seemingly solid structure, yet also pour sand from one bucket to another as easily as we pour a glass of water. It can act on one hand like a solid, yet on the other like a liquid. If the material is forced together, it becomes very stiff. For instance, coffee, which is also a granular material, becomes stiff like a brick when packaged under vacuum. Conversely, if the material is only loosely held together, it can be soft, weak, and can even display properties found in liquids such as flow.