Effect of soil microstructure on the compressibility of natural Singapore marine clay

2008 ◽  
Vol 45 (2) ◽  
pp. 161-176 ◽  
Author(s):  
Han-Eng Low ◽  
Kok-Kwang Phoon ◽  
Thiam-Soon Tan ◽  
Serge Leroueil
Keyword(s):  
Yield Stress ◽  
Void Ratio ◽  
Empirical Method ◽  
Marine Clay ◽  
High Quality ◽  
Compression Curve ◽  
One Dimensional ◽  
Soil Microstructure ◽  
Ratio Difference ◽  
Constant Rate

The effect of soil microstructure on the compressibility of natural Singapore marine clay is studied in this paper. It was found that natural Singapore marine clay can sustain higher void ratio than reconstituted Singapore marine clay at the same effective stress in one-dimensional compression. This difference is most noticeable between yield stress and two times the yield stress. This void ratio difference is commonly attributed to soil microstructure, and the decrease in this difference at higher stresses is attributed to progressive destructuration. As a consequence of progressive destructuration, the virgin compression curve is nonlinear and the compression index along the virgin compression range is variable, which is only noticeable during the constant rate of strain consolidation test on high-quality samples. In the absence of high-quality samples and constant rate of strain consolidation tests, an empirical method is proposed to obtain a first-order estimation of a nonlinear virgin compression curve using index properties and yield stress. This paper demonstrates that the proposed method works reasonably well with natural Singapore marine clay. The error bound for the predicted compression indices is approximately ±20% of the compression indices measured with constant rate of strain test on high-quality samples.

Effect of cementation on the compressibility of Singapore upper marine clay

2008 ◽  
Vol 45 (7) ◽  
pp. 1018-1024 ◽  
Author(s):  
Han-Eng Low ◽  
Kok-Kwang Phoon
Keyword(s):  
Ethylene Diamine Tetraacetic Acid ◽  
Amorphous Materials ◽  
Soil Samples ◽  
Ethylene Diamine ◽  
Clay Layer ◽  
Tetraacetic Acid ◽  
Marine Clay ◽  
High Quality ◽  
One Dimensional ◽  
Soil Microstructure

A series of one-dimensional consolidation tests were performed under varying pretreatments on high quality soil samples collected from a Singapore upper marine clay layer in an attempt to evaluate the effect of cementation by amorphous materials on its compressibility. The findings from this study seem to suggest that cementation by ethylene-diamine tetraacetic acid (EDTA) removable amorphous materials may only partially contribute to the development of soil microstructure and overconsolidation in Singapore upper marine clay.

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.

Influence of initial water content and strain rate on remolded yield stress in marine clay

2021 ◽  
pp. 1-8
Author(s):  
Xiaobing Li ◽  
Jianpeng Chen ◽  
Xiuqing Hu ◽  
Hongtao Fu ◽  
Jun Wang ◽  
...  
Keyword(s):  
Strain Rate ◽  
Water Content ◽  
Yield Stress ◽  
Initial Water Content ◽  
Marine Clay ◽  
Initial Water

scholarly journals High performance self-powered photodetector based on 1D Te-2D WS2 mixed-dimensional heterostructure

2021 ◽  
Author(s):  
Lixiang Han ◽  
Mengmeng Yang ◽  
Peiting Wen ◽  
Wei Gao ◽  
nengjie huo ◽  
...  
Keyword(s):  
High Performance ◽  
Van Der Waals ◽  
Sharp Interface ◽  
Two Dimensional ◽  
High Quality ◽  
One Dimensional ◽  
Self Powered

One dimensional (1D)-two dimensional (2D) van der Waals (vdWs) mixed-dimensional heterostructures with advantages of atomically sharp interface, high quality and good compatibility have attracted tremendous attention in recent years. The...

Numerical assessment on the performance of variable area single- and two-stage ejectors: A comparative study

2021 ◽  
pp. 095440892110331
Author(s):  
Anil Kumar ◽  
Virendra Kumar ◽  
PMV Subbarao ◽  
Surendra K Yadav ◽  
Gaurav Singhal
Keyword(s):  
Change Theory ◽  
Single Stage ◽  
Two Stage ◽  
Entrainment Ratio ◽  
Ansys Fluent ◽  
One Dimensional ◽  
Flow Parameters ◽  
Constant Rate ◽  
Numerical Assessment ◽  
The One

The two-stage ejector has been suggested to replace the single-stage ejector geometrical configuration better to utilize the discharge flow’s redundant momentum to induce secondary flow. In this study, the one-dimensional gas dynamic constant rate of momentum change theory has been utilized to model a two-stage ejector along with a single-stage ejector. The proposed theory has been utilized in the computation of geometry and flow parameters of both the ejectors. The commercial computational fluid dynamics tool ANSYS-Fluent 14.0 has been utilized to predict performance and visualize the flow. The performance in terms of entrainment ratio has been compared under on- design and off-design conditions. The result shows that the two-stage ejector configuration has improved (≈57%) entrainment capacity than the single-stage ejector under the on-design condition.

scholarly journals Post-liquefaction reconsolidation of sand

2016 ◽  
Vol 472 (2186) ◽  
pp. 20150745 ◽  
Author(s):  
O. Adamidis ◽  
G. S. P. Madabhushi
Keyword(s):  
Void Ratio ◽  
One Dimensional ◽  
Geotechnical Centrifuge ◽  
Significant Damage ◽  
Pore Water Pressures ◽  
The One ◽  
Crucial Parameter ◽  
Excess Pore ◽  
Good Agreement ◽  
Made In

Loosely packed sand that is saturated with water can liquefy during an earthquake, potentially causing significant damage. Once the shaking is over, the excess pore water pressures that developed during the earthquake gradually dissipate, while the surface of the soil settles, in a process called post-liquefaction reconsolidation. When examining reconsolidation, the soil is typically divided in liquefied and solidified parts, which are modelled separately. The aim of this paper is to show that this fragmentation is not necessary. By assuming that the hydraulic conductivity and the one-dimensional stiffness of liquefied sand have real, positive values, the equation of consolidation can be numerically solved throughout a reconsolidating layer. Predictions made in this manner show good agreement with geotechnical centrifuge experiments. It is shown that the variation of one-dimensional stiffness with effective stress and void ratio is the most crucial parameter in accurately capturing reconsolidation.

scholarly journals Research on Pseudorandom Number Generator Based on Several New Types of Piecewise Chaotic Maps

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Hongyan Zang ◽  
Yue Yuan ◽  
Xinyuan Wei
Keyword(s):  
Theoretical Basis ◽  
Chaotic Maps ◽  
Dynamic Properties ◽  
Chaotic Map ◽  
Pseudorandom Number ◽  
Pseudorandom Number Generator ◽  
Number Generator ◽  
High Quality ◽  
One Dimensional ◽  
Construction Methods

This paper proposes three types of one-dimensional piecewise chaotic maps and two types of symmetrical piecewise chaotic maps and presents five theorems. Furthermore, some examples that satisfy the theorems are constructed, and an analysis and model of the dynamic properties are discussed. The construction methods proposed in this paper have a certain generality and provide a theoretical basis for constructing a new discrete chaotic system. In addition, this paper designs a pseudorandom number generator based on piecewise chaotic map and studies its application in cryptography. Performance evaluation shows that the generator can generate high quality random sequences efficiently.

Building the Panoramic Image for Mobile Robot Localization

2013 ◽  
Vol 365-366 ◽  
pp. 967-970 ◽  
Author(s):  
Vladimir Popov ◽  
Anna Gorbenko
Keyword(s):  
Mobile Robot ◽  
Robot Navigation ◽  
String Matching ◽  
Mobile Robot Navigation ◽  
Robot Localization ◽  
Panoramic Image ◽  
High Quality ◽  
Visual Landmarks ◽  
One Dimensional ◽  
Mobile Robot Localization

Visual landmarks are extensively used in contemporary robotics. There are a large number of different systems of visual landmarks. In particular, fingerprints give us unique identifiers for visually distinct locations by recovering statistically significant features. Therefore, fingerprints can be used as visual landmarks for mobile robot navigation. To create fingerprints we need one-dimensional color panoramas of high quality. In this paper, we consider a method for building the panoramic image using string matching algorithms. In particular, we propose the shortest common ordered supersequence problem.

Yield stress evaluation of Finnish clays based on analytical piezocone penetration test (CPTu) models

2020 ◽  
Vol 57 (11) ◽  
pp. 1623-1638 ◽  
Author(s):  
Bruno Di Buò ◽  
Marco D’Ignazio ◽  
Juha Selänpää ◽  
Tim Länsivaara ◽  
Paul W. Mayne
Keyword(s):  
Yield Stress ◽  
Soil Mechanics ◽  
Friction Angle ◽  
Coefficient Of Determination ◽  
Soil Conditions ◽  
Piezocone Penetration Test ◽  
Bias Factor ◽  
Constant Rate ◽  
Target Values ◽  
Spherical Cavity Expansion

A well-established analytical model based on spherical cavity expansion and critical state soil mechanics theories is applied to piezocone soundings for profiling the yield stress and overconsolidation ratio of five soft sensitive test sites located in Finland. Yield stress is related to three piezocone parameters: net cone resistance, excess porewater pressure, and effective cone resistances. Input geoparameters include the effective stress friction angle, defined at both peak strength and at maximum obliquity, and the model directly provides the operational value of the undrained rigidity index. The piezocone-evaluated profiles compare favorably with results from laboratory constant-rate-of-strain consolidation tests for all the investigated sites. Based on the obtained experimental results, simplified correlations valid for Finnish soil conditions are derived. Their validity is assessed based on the bias factor, coefficient of variation, and coefficient of determination, showing a fairly good agreement between the predicted and the target values.

SOFT SOIL IMPROVEMENT USING CHEMICAL-RUBBER CHIPS MIXTURE

2015 ◽  
Vol 76 (2) ◽  
Author(s):  
Aminaton Marto ◽  
Norazirah Aziz ◽  
Mohammed Ridzuan Jahidin ◽  
Nor Zurairahetty Mohd Yunus ◽  
Fauziah Kasim ◽  
...  
Keyword(s):  
Void Ratio ◽  
Soft Soil ◽  
Soil Improvement ◽  
Soil Test ◽  
Unconfined Compression ◽  
Marine Clay ◽  
Untreated Sample ◽  
Unconfined Compression Test ◽  
Soft Soils ◽  
Clay Particles

Soft soils are widely found in many areas around the world as well as in Malaysia. Marine clay is one of the problematic soft soils. The marine clay should be pretreated before the construction to enhance the usability and serviceability of highway constructed on this type of soil. This paper presents the research results on the usability of chemical (SH-85)-rubber chips mixtures as the stabilizing agent in improving the characteristics of marine clay from two engineering perspectives; the strength and the compressibility. Three types of laboratory tests were conducted; index soil test, unconfined compression test and oedometer test. The results show that the treated samples had higher unconfined compressive strength compared to untreated sample. The strength of marine clay increased when the amount of the SH-85 increased.  The void ratio reduced in value when the chemical-rubber chips mixture was added to the marine clay. It is due to the chemical that acts as a binder that interlocks the rubber chips and the marine clay particles, reducing the compressibility. It has been concluded that the mixture of chemical-rubber chips with 8 % SH-85 plus 1 % of rubber chips is more effectively improved the characteristics of marine clay.  

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