Stochastic Failure of a Double Eccentricity Footing Settlement on Cohesive Soils with a Modified Cam Clay Yield Surface

Author(s):  
Ambrosios A. Savvides
2011 ◽  
Vol 71-78 ◽  
pp. 1073-1078
Author(s):  
Xiao Xia Guo ◽  
Bo Ya Zhao

In order to construct a constitutive model taking into the effect of both the fabric tensors and their evolution modes, this paper links modern ideas of thermomechanics opinion to the theory of fabric tensors. The anisotropic dissipation incremental function of modified Cam-clay constitutive model considering the effect of fabric characteristic can be obtained by establishing the relation between microstructure and plastic volume strain. After discussing the yield surfaces in the dissipative and the true stress space from the viewpoint of the evolution mode of the fabric tensors, the results indicate that the slope of the normal consolidation line and the critical state line will be governed by changes of void fabric. The model successfully captures most salient behaviors of granular materials related to fabric issues. In the dissipative stress space, the void of granular materials can rearrange and show more anisotropic. In the true stress space, fabric not only affects the deflection of the yield surface, but also affects the hardening rule.


2004 ◽  
Vol 41 (6) ◽  
pp. 1250-1258 ◽  
Author(s):  
J -C Chai ◽  
N Miura ◽  
H -H Zhu ◽  
Yudhbir

The compression and consolidation behavior of some structured natural clays are discussed. It is shown that for some structured natural clays, the relation between void ratio (e) and mean effective stress (p′) is more linear in a ln(e + ec) – ln(p′) plot (where ec is a soil parameter) than in an e – ln(p′) plot. It is proposed that for structured natural clay with a sensitivity value greater than 4, a linear ln(e + ec) – ln(p′) relation can be used in settlement and consolidation calculation. The effect of introducing a linear ln(e + ec) – ln(p′) relation on the calculated load–settlement curve and consolidation behavior of structured clays is discussed. The linear ln(e + ec) – ln(p′) relation was incorporated into the modified Cam–clay model by modifying the hardening law of the model. It is shown that using the linear ln(e + ec) – ln(p′) relation simulated the consolidation behavior of the structured natural clays better than using the linear e – ln(p′) relation.Key words: structured natural clay, compression, consolidation, constitutive model, numerical analysis.


2016 ◽  
Vol 837 ◽  
pp. 68-74
Author(s):  
Rafal Uliniarz

The paper presents a reasonably advanced constitutive law for soil – a hybrid of the Modified Cam Clay and a new RU development. The Modified Cam Clay model is an isotropic hardening elasto – plastic model originated by Burland in 1967 [1] within the critical state soil mechanics. This model describes realistically mechanical soil behaviour in normal consolidation states. The other one is designed to ensure more adequate soil responses to reloading paths, particularly in the range of small strains. The RU+MCC model has been implemented in the FEM computer code Z_SOIL.pc. To test the influence of the small strain nonlinearity on soil – structure interaction as well as to exhibit the ability of the proposed model to simulate realistically this effect, a comparative study based on the FEM solution has been carried out. As a benchmark a trial loading test of strip footing was used.


Author(s):  
Aleksandar D. Spasojević ◽  
Dejan M. Divac ◽  
Nenad M. Šušić

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