scholarly journals One-Dimensional Nonlinear Consolidation Analysis Using Hansbo’s Flow Model and Rebound-Recompression Characteristics of Soil under Cyclic Loading

2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Banghua Zhu ◽  
Gang Shi ◽  
Zihe Wei
Keyword(s):  
Cyclic Loading ◽  
Effective Stress ◽  
Void Ratio ◽  
Flow Model ◽  
Soft Clay ◽  
Real Life ◽  
Excess Pore Pressure ◽  
One Dimensional ◽  
Consolidation Degree ◽  
Consolidation Analysis

Hansbo’s flow model for one-dimensional consolidation analysis of saturated clay has been widely recognized as being the most representative for soft soils. Many studies have used the model to examine the characteristics of soil under various conditions. However, very few studies have considered soil under cyclic loading. In this study, using a Hansbo’s flow model and assuming known characteristics for soft clay deformation and rebound and recompression of soil, the one-dimensional consolidation model of soft clay under cyclic loading is established. A FlexPDE solution scheme with excess pore pressure u and void ratio e as variables is also given. The reliability of the proposed method is verified by comparing the obtained results with existing results. On this basis, the consolidation characteristics of soft clay foundations under unilateral drainage and cyclic loading are studied. The effects of soil rebound and recompression characteristics, Hansbo’s flow parameters, cyclic loading period, and cyclic loading form on the consolidation characteristics of soft clay foundation are analyzed. The results show that under cyclic loading, the effective stress, void ratio, and average consolidation degree of the foundation all present a cyclic state and gradually enter a stable cyclic state with the increase in cycles. The peak of effective stress lags behind the peak of cyclic load. The rebound and recompression characteristics of soil have little effect on the effective stress of soil but a great effect on the void ratio. In contrast to its characteristic under linear loading, the average consolidation degree of the foundation under cyclic loading finally enters a stable cyclic state. The results of the analysis can be used as a reference in the analysis of real life highways, railways, subway tunnels built on soft soil foundations subjected to periodic cyclic loading.

Uncertainty of One-Dimensional Consolidation of Multi-Layered Soft Clay Soils

2011 ◽  
Vol 250-253 ◽  
pp. 1838-1841
Author(s):  
Xiao Yong Li
Keyword(s):  
Soft Clay ◽  
Compression Modulus ◽  
Probability Characteristic ◽  
Coefficient Of Consolidation ◽  
One Dimensional ◽  
The Monte Carlo Method ◽  
Consolidation Coefficient ◽  
Characteristic Values ◽  
Consolidation Degree ◽  
Substantial Degree

The measured coefficient of consolidation can have a substantial degree of variation even in a uniform clay layer. The probability characteristic values for such parameters as consolidation coefficient and compression modulus are analyzed from local engineering data. This paper, through a probabilistic analysis, examines the variability of one-dimensional consolidation solutions. The multilayer models are evaluated. Then the Monte Carlo method is used to develop solutions for one dimensional consolidation. It identified the influence of the parameter uncertainty on the probability characteristic of the consolidation degree. The uncertainty of consolidation coefficient has a great impact on the probabilistic characteristics of the consolidation degree, but for compression modulus it is opposite true. It proposed a simplification analysis method that considers only the uncertainty of consolidation coefficient without consideration of the uncertainty of compression modulus, and its erroneous precision can meet the engineering requirements.

scholarly journals One-dimensional large-strain thaw consolidation using nonlinear effective stress – void ratio – hydraulic conductivity relationships

2018 ◽  
Vol 55 (3) ◽  
pp. 414-426 ◽  
Author(s):  
Simon Dumais ◽  
Jean-Marie Konrad
Keyword(s):  
Heat Transfer ◽  
Hydraulic Conductivity ◽  
Effective Stress ◽  
Void Ratio ◽  
Moving Boundary ◽  
Initial Conditions ◽  
Large Strain ◽  
One Dimensional ◽  
Consolidation Theory ◽  
Thaw Consolidation

A one-dimensional model for the consolidation of thawing soils is formulated in terms of large-strain consolidation and heat-transfer equations. The model integrates heat transfer due to conduction, phase change, and advection. The hydromechanical behaviour is modelled by large-strain consolidation theory. The equations are coupled in a moving boundary scheme developed in Lagrangian coordinates. Finite strains are allowed and nonlinear effective stress – void ratio – hydraulic conductivity relationships are proposed to characterize the thawing soil properties. Initial conditions and boundary conditions are presented with special consideration for the moving boundary condition at the thaw front developed in terms of large-strain consolidation. The proposed model is applied and compared with small-strain thaw consolidation theory in a theoretical working example of a thawing fine-grained soil sample. The modelling results are presented in terms of temperature, thaw penetration, settlements, void ratio, and excess pore-water pressures.

Modelling the combined effect of strain rate and temperature on one-dimensional compression of soils

2008 ◽  
Vol 45 (12) ◽  
pp. 1765-1777 ◽  
Author(s):  
L. Laloui ◽  
S. Leroueil ◽  
S. Chalindar
Keyword(s):  
Strain Rate ◽  
Yield Stress ◽  
Effective Stress ◽  
Void Ratio ◽  
Coupled Model ◽  
One Dimensional ◽  
The Third ◽  
Proposed Model ◽  
Effects Of Temperature ◽  
Advanced Model

Strain rate and temperature have important effects on the behaviour of soils. The present paper enhances the thermoviscoplastic modelling of soils by taking advantage of the most recent understanding of the effects of temperature and strain rate on soils. In particular, modelling of the evolution of the vertical yield stress at any void ratio is made possible with the use of an advanced model for the dependence of vertical yield stress on temperature, as well as the use of the unique effective stress–strain – strain rate concept. The first part of the paper presents an overview of the experimental and constitutive theoretical works performed on the effects of strain rate and temperature. The second part describes a strain rate and temperature coupled model, and the third part deals with the numerical validation of the proposed model.

scholarly journals Behaviour of saturated railway track foundation materials during undrained cyclic loading

2018 ◽  
Vol 55 (5) ◽  
pp. 689-697 ◽  
Author(s):  
Anna Mamou ◽  
Jeffrey A. Priest ◽  
Christopher R.I. Clayton ◽  
William Powrie
Keyword(s):  
Shear Stress ◽  
Cyclic Loading ◽  
Pore Pressure ◽  
Void Ratio ◽  
Axial Strain ◽  
Railway Track ◽  
Excess Pore Pressure ◽  
Cyclic Shear ◽  
Stress Threshold ◽  
Excess Pore

This paper presents results of a series of hollow cylinder tests carried out to investigate the undrained behaviour of saturated railway track foundation materials during cyclic loading involving principal stress rotation. Four sand–clay mixes representative of real railway track foundation materials were investigated. It was found that moderate additions of clay (up to ∼14% by weight) increased the cyclic shear stress threshold at which significant excess pore pressures started to accumulate. After the cyclic shear stress threshold had been exceeded, the rate of pore pressure increase with the logarithm of axial strain was greatest for the material having a clay content of 11%. Excess pore pressure generation reduced with increasing intergranular and global void ratio, with the global void ratio being perhaps the more useful indicator because of the reduced amount of scatter and higher correlation of the idealized relationship.

A ONE-DIMENSIONAL TWO-PHASE FLOW MODEL AND EXPERIMENTAL VALIDATION FOR A FLASHING VISCOUS LIQUID IN A SPLASH PLATE NOZZLE

2015 ◽  
Vol 25 (9) ◽  
pp. 795-817 ◽  
Author(s):  
Mika P. Jarvinen ◽  
A. E. P. Kankkunen ◽  
R. Virtanen ◽  
P. H. Miikkulainen ◽  
V. P. Heikkila
Keyword(s):  
Viscous Liquid ◽  
Experimental Validation ◽  
Flow Model ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Two Phase ◽  
One Dimensional
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