NONLINEAR SOIL MODELS FOR IRREGULAR CYCLIC LOADINGS

This paper contains two discussions of a paper pretaining to soil stress-strain models as well as a closure by the author of that paper, which is a response to the discussions. The first writer discusses the cyclic loading behavior of another type of soil stress-strain model, which has two basic starting points: the framework of critical state soil mechanics and the mathematical framework provided by work hardening plasticity. The model requires four parameters to enable a wide range of behavior to be modelled; and with the inclusion of a fifth parameter, the small strain amplitude elastic shear modulus, the model gives a very good representation of the effect of strain amplitude on the apparent shear modulus and the equivalent viscous damping ratio for steady state loading between fixed limits. In the second discussion, the writer mentions that the author misunderstood his past uses of the Ramberg- Osgood curves to represent soil behavior. He decribes as incorrect the author's statement that "A third solution, used by Richart (20) consists of simply limiting the shear stress that can be developed at any time to a value no greater than the shear strength as shown by Path C in Fig. 4." In the closure, the writer expresses some skepticism about the first discusser's model's ability to track soil behavior under more complex, cyclic loading conditions under which, for instance, loading history dependent volume changes or pore pressure changes occur; and he acknowledges and expresses regret that he misunderstood the second discusser's representation of the Ramberg-Osgood Curves.

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  • Accession Number: 00324519
  • Record Type: Publication
  • Report/Paper Numbers: ASCE 15829
  • Files: TRIS
  • Created Date: May 21 1981 12:00AM