16 - Barodesy

Summary

Barodesy is developed on the basis of the relation between proportional strain paths and proportional stress paths and of the fading memory of soil. This relation is mathematically described by means of a matrix exponential. The fine tuning of barodesy is obtained by consideration of limit states and the dilatancy prevailing there. A new approach to critical states is presented which leaves the hitherto considered critical state line unchanged but introduces an evolution equation for the critical void ratio at non-critical states. It is shown that barodesy includes basic and well-known concepts of soil behaviour. It is shown that the same equation of barodesy holds for sand and clay. Simulations of element tests, oedometric, triaxial drained and undrained ones, show that barodesy is capable of describing them in a satisfactory way, though using equations of outstanding simplicity. In addition, the simulations of cyclic tests exhibiting liquefaction and cyclic mobility are satisfactory.