<論文>過圧密粘土のひずみ速度効果

概要

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In the consolidated undrained triaxial test for clays, the strain controlled test is commonly used in a laboratory. The embankment work on soft grounds, however, is not controlled by the strain rate and approximated by the stress controlled condition. The strain rate or loading rate in a laboratory test is relatively higher than that of the field. It is well known that the undrained stress-strain relation of saturated clays can be significantly affected by the applied loading rate. This effect has been studied and almost research subjects were concerned with secondary compression of normally consolidated clays. In these studies, it seems that little attention has been paid to overconsolidated clays because of the typical elastic behavior. It is the purpose of this paper to clarify the influence of secondary compression on strain rate effect by using an elasto-viscoplastic constitutive model and to evaluate experimentally time dependent undrained behavior of saturated overconsolidated clays. The results showed that undrained strength of isotropic overconsolidated, K_0 normally and overconsolidated clay were almost insensitive to the strain rate. The K_0 normally consolidated clay in the field is subjected to long term secondary compression and may be almost quasi pre-consolidated state. It can be expected that quasi overconsolidated clays are rate independent as well as overconsolidated clays.
東海大学の論文
2002-09-30