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Research on Effective Stress Constitutive Relation of Structural Loess under Coupling of Stress and Moisture

Author: CaoChengMing
Tutor: ChenCunLi
School: Xi'an University of Technology
Course: Geotechnical Engineering
Keywords: structural loess equivalent stress of structure fluid equivalent partial stress of structure fluid equivalent ball stress of structure fluid constitutive relation coupling of saturation and stress
CLC: TU444
Type: Master's thesis
Year: 2010
Downloads: 56
Quote: 0
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Abstract

Building transmission load couple with the water content of the loess changes which causes by changing groundwater levels、precipitation infiltration or living and production water excretion, this will inevitably lead to strength reduced and deformation increase of loess, affect the normal use of the buildings. So, the loess under coupling of saturation and stress constitutive relation and other hot issues of loess should be made more in-depth studies, so it lay a theoretical foundation for the the change from the greatest amount of design collapsibility to the possible, improve the design method of loess foundation, it will have important theoretical and practical significance. Therefore, in this paper, on the basis of a careful analysis of existing research results of structural loess, established effective stress constitutive relation and stress of structural loess under coupling of saturation and stress as a research goal of this article.First, through the compression tests on intact, remolded and manpower structural loess with different initial humidity,analyzing the difference on compression characteristics of unsaturated loess and saturated loess with different water content based on the principle of equivalent deformation, according to the principle of deformation equivalence, with the same void ratio of unsaturated loess under the same dry density and compressive stress the difference between saturated loess defines the structure of fluid equivalent stress pw, made effective stress expressions of unsaturated loess and can reflect the structural fluid equivalent stress expression pw of structure loess under stress and humidity coupled fluid under the condition of compressive stress,studies the expression changes of parameters with the characteristics of a variety of factors, meanwhile, based on unsaturated loess principle of effective stress introduction compressed fluid structure in saturated loess compression curves, establishes compression curves model of structural loess, and verified the rationality of this model. Secondly, through the isotropic compression and conventional triaxial test on intact, remolded and manpower structural loess with different initial water content, analyzing the difference on shear properties of unsaturated loess and saturated loess with different humility, according to the principle of deformation equivalence, with the same partial strain of unsaturated loess under the same dry density and partial stress the difference between saturated loess and with the same void ratio of unsaturated loess under the same dry density and ball stress the difference between saturated loess define the structure of fluid equivalent partial stress qw and the structure of fluid equivalent partial stress pw, made effective stress expressions of unsaturated loess and can reflect the structural fluid equivalent partial stress expression pw and the structural fluid equivalent ball stress expression pw of structure loess under stress and humidity coupled fluid under the condition of triaxial stress,studies the expression changes of parameters with the characteristics of a variety of factors.Finally, According to non-saturated loess principle of effective stress, In the triaxial stress conditions, the structural fluid equivalent partial stress expression and the structural fluid equivalent ball stress expression introduce saturated loess constitutive relation and saturated loess effective stress shear strength of expression,made the effective stress constitutive relationship and effective stress shear strength of expression on structural loess under the coupling of stress and moisture.,based on which, the stress-strain curve of intact loess is calculated, and the results are accord with the test tesults.

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CLC: > Industrial Technology > Building Science > Soil mechanics,foundation engineering > Various types of soil and foundation > Loess and foundation
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