The Residual Stress in Thawing Soils

1973 ◽  
Vol 10 (4) ◽  
pp. 571-580 ◽  
Author(s):  
J. F. Nixon ◽  
N. R. Morgenstern
Keyword(s):  
Residual Stress ◽  
Effective Stress ◽  
Simple Procedure ◽  
Frozen Soil ◽  
Fine Grained ◽  
Deformation Properties ◽  
Fine Grained Soil ◽  
Soil Skeleton ◽  
Strength And Deformation ◽  
Undrained Strength

If a fine grained soil is thawed under undrained conditions, in general an effective stress exists in the soil skeleton. This effective stress is termed the residual stress. In ice-rich soil the residual stress may be zero, but various combinations of stress and thermal histories can result in significant residual stresses being generated upon thawing.A simple procedure for measuring the residual stress is described and the method is employed to obtain values for the residual stress in natural and reconstituted samples of frozen soil. The residual stress is found to be dependent on the void ratio in the thawed undrained condition. A profile of the residual stress with depth is given for the natural permafrost samples that have been tested.Some implications of the residual stress in practice are discussed, with particular emphasis on the undrained strength and deformation properties of thawed permafrost.

scholarly journals Assessment for Thermal Conductivity of Frozen Soil Based on Nonlinear Regression and Support Vector Regression Methods

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Fu-Qing Cui ◽  
Wei Zhang ◽  
Zhi-Yun Liu ◽  
Wei Wang ◽  
Jian-bing Chen ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Support Vector Regression ◽  
Nonlinear Regression ◽  
Prediction Accuracy ◽  
Prediction Models ◽  
Frozen Soil ◽  
Support Vector ◽  
Soil Thermal Conductivity ◽  
Fine Grained ◽  
Fine Grained Soil

The comprehensive understanding of the variation law of soil thermal conductivity is the prerequisite of design and construction of engineering applications in permafrost regions. Compared with the unfrozen soil, the specimen preparation and experimental procedures of frozen soil thermal conductivity testing are more complex and challengeable. In this work, considering for essentially multiphase and porous structural characteristic information reflection of unfrozen soil thermal conductivity, prediction models of frozen soil thermal conductivity using nonlinear regression and Support Vector Regression (SVR) methods have been developed. Thermal conductivity of multiple types of soil samples which are sampled from the Qinghai-Tibet Engineering Corridor (QTEC) are tested by the transient plane source (TPS) method. Correlations of thermal conductivity between unfrozen and frozen soil has been analyzed and recognized. Based on the measurement data of unfrozen soil thermal conductivity, the prediction models of frozen soil thermal conductivity for 7 typical soils in the QTEC are proposed. To further facilitate engineering applications, the prediction models of two soil categories (coarse and fine-grained soil) have also been proposed. The results demonstrate that, compared with nonideal prediction accuracy of using water content and dry density as the fitting parameter, the ternary fitting model has a higher thermal conductivity prediction accuracy for 7 types of frozen soils (more than 98% of the soil specimens’ relative error are within 20%). The SVR model can further improve the frozen soil thermal conductivity prediction accuracy and more than 98% of the soil specimens’ relative error are within 15%. For coarse and fine-grained soil categories, the above two models still have reliable prediction accuracy and determine coefficient (R2) ranges from 0.8 to 0.91, which validates the applicability for small sample soils. This study provides feasible prediction models for frozen soil thermal conductivity and guidelines of the thermal design and freeze-thaw damage prevention for engineering structures in cold regions.

scholarly journals Cracking behaviour of fine-grained soils: from laboratory testing to numerical modelling

2019 ◽  
Vol 92 ◽  
pp. 16004
Author(s):  
Pierre Gerard ◽  
Ian Murray ◽  
Alessandro Tarantino
Keyword(s):  
Effective Stress ◽  
Failure Criterion ◽  
Shear Failure ◽  
Digital Camera ◽  
Failure Criteria ◽  
Fine Grained ◽  
Fine Grained Soil ◽  
Desiccation Cracking ◽  
Stress States ◽  
Stress Dependent

Many experimental evidences suggest that desiccation cracks in clay initiate as a result of the mobilization of soil tensile strength. However this mechanical approach disregards the cohesionless and effective stress-dependent behaviour of fine-grained soil. On the other hand recent findings in the literature suggest that effective stress-dependent shear failure criteria would be appropriate to explain the mechanisms of desiccation cracking for tensile total stress states. This work aims at assessing the validity of a shear failure criterion to predict the onset of cracking in clay forms exposed to air drying. Clay forms of various geometries were experimentally subjected to non-uniform hydraulic and mechanical boundary conditions. Time and location for crack initiation are monitored using a digital camera. Cracking experiments are then modelled in a hydro-mechanical framework using an effective-stress shear failure criterion. The comparison of simulations with experimental results for both the time and the location of cracking allows assuming that cracking occurs due to failure in shearing.

scholarly journals Testing Deformation and Compressive Strength of the Frozen Fine-Grained Soils with Changed Porosity and Density

2021 ◽  
Vol 11 (2) ◽  
pp. 113-120
Author(s):  
V. Lemenkov ◽  
Polina Lemenkova
Keyword(s):  
Compressive Strength ◽  
Frozen Soil ◽  
External Effects ◽  
Frozen Soils ◽  
Load Pressure ◽  
Temperature Changes ◽  
Fine Grained ◽  
External Conditions ◽  
Loam Soil ◽  
Strength And Deformation

Abstract Current paper focuses on the laboratory experiments performed wit aim to test the deformation in the frozen loam soil specimens. Loam frozen soils are subject to the external effects, such as climate and environmental impacts including temperature changes. Soil heave is one of the key features restraining possible area development: construction of buildings, roads and railways. Necessarily, this requires the improvements of methods of the assessment of heave. This research evaluated the compressive strength and deformation in several specimens of the frozen soil. The approach included varying load and physical properties of soil specimens: porosity, pore filling, moisture, density of soil particles and dry soil density. Besides during the experiment, the external conditions were changed: decreased temperature and increased load pressure. The experiment is based on the UPG-MG4-01. The paper presented the laboratory tests of heave and compressive strength of the frozen soils using applied geotechnical methods.

Effective Fine-Grained Concrete with High-Dispersed Additive Based on the Natural Mineral Wollastonite

2019 ◽  
Vol 945 ◽  
pp. 85-90 ◽  
Author(s):  
E.G. Karpikov ◽  
N.P. Lukutsova ◽  
E.A. Bondarenko ◽  
V.V. Klyonov ◽  
A.E. Zajcev
Keyword(s):  
Raw Materials ◽  
Selective Adsorption ◽  
Aggregate Stability ◽  
Rheological Parameters ◽  
Ultrasonic Dispersion ◽  
Natural Mineral ◽  
Fine Grained ◽  
Deformation Properties ◽  
Strength And Deformation ◽  
Micro Fillers

Micro-fillers based on natural mineral wollastonite, modifying fine-grained concrete and improving its physical and mechanical characteristics, are developed and studied. The influence of the most common stabilizers on the aggregate stability of wollastonite-based microdispersed systems in the aquatic dispersion environment is considered. The optimal parameters, ensuring the production of micro-fillers in the form of stable suspensions, are developed. The application efficiency of the wollastonite-based filler due to its micro-reinforcing properties is revealed. These properties are specified by the formation of needle-shaped crystals by the ultrasonic dispersion in the aquatic environment, chemically related to cement-containing raw materials and contributing to the active selective adsorption of the binder hydration products. It has a significant influence on the rheological parameters of cement composites, on structure formation, as well as on their strength and deformation properties.

scholarly journals EFFECT OF DOSAGE OF REDISPUTABLE POWDERS AND THE TYPE OF LOW-MODULAR INCLUSIONS ON THE PROPERTIES OF FINE-AGGREGATE CONCRETE

2019 ◽  
Vol 46 (2) ◽  
pp. 167-175 ◽  
Author(s):  
A. V. Dolgova ◽  
G. V. Nesvetaev
Keyword(s):  
Fine Aggregate ◽  
Fine Grained ◽  
Deformation Properties ◽  
Low Modulus ◽  
Strength And Deformation ◽  
Properties Of Materials ◽  
Materials Used ◽  
Entrained Air ◽  
Polymer Powders

Objectives Reliability and durability of structures using materials with various properties (plaster coatings, cement glue, new concrete during repair and restoration of structures, etc.) largely depends on the adhesion of the layers and the deformation properties of the coatings. To obtain the required properties of materials used for coatings, modifiers based on polymers and low-modulus inclusions are introduced into the composition of new concretes, for example, entrained air. The aim of the work is to identify some patterns of change in the properties of concrete with the joint introduction of these modifiers.Method Experimental determination of the tensile strength in bending, compression, E-modulus, adhesion to the concrete base by standard methods.Result The influence of separate and joint introduction of dispersible polymer powders and various low-modulus inclusions into the composition of fine-grained concrete has been established.Conclusion The joint introduction to the composition of fine-grained concrete of various low-modulus inclusions and redispersible polymer powders provides a reduction in the stress level during forced deformations due to the different effects additives on the strength and deformation properties and contributes to increased adhesion to the concrete. 

scholarly journals The Influence of Specimen Geometry and Loading Conditions on the Mechanical Properties of Porous Brittle Media

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7144
Author(s):  
Anatoly M. Bragov ◽  
Andrey K. Lomunov ◽  
Leonid A. Igumnov ◽  
Aleksandr A. Belov ◽  
Victor A. Eremeyev
Keyword(s):  
Porous Media ◽  
Dynamic Stress ◽  
Uniaxial Stress ◽  
Dynamic Tests ◽  
Zirconia Ceramics ◽  
Specimen Length ◽  
Fine Grained ◽  
Optimal Geometry ◽  
Deformation Properties ◽  
Strength And Deformation

Dynamic tests of fine-grained fired dioxide-zirconia ceramics under compression under uniaxial stress conditions were carried out. The influence of the specimen length on the obtained strength and deformation properties of ceramics is investigated. The thickness of the specimen has a significant impact on the course of the obtained dynamic stress–strain diagrams: short specimens have a much more sloping area of active loading branch. The main contribution to the modulus of the load branch resulting from tests of brittle porous media is made by the geometry of the specimens and the porosity of the material. When choosing the length of specimens for dynamic tests, the optimal geometry of the tested specimens is preferable in accordance with the Davies–Hunter criterion, when the contributions of axial and radial inertia are mutually compensated, and the contribution of the effects of friction in the resulting diagram is minimal. When choosing the geometry of specimens of brittle porous media, the structure of the material should be taken into account so that the size of the specimen (both length and diameter) exceeds the size of the internal fractions of the material by at least five times.

scholarly journals Modeling the Compaction Characteristics of Fine-Grained Soils Blended with Tire-Derived Aggregates

2021 ◽  
Vol 13 (14) ◽  
pp. 7737
Author(s):  
Amin Soltani ◽  
Mahdieh Azimi ◽  
Brendan C. O’Kelly
Keyword(s):  
Energy Levels ◽  
Model Development ◽  
Dry Mass ◽  
Unit Weight ◽  
Power Functions ◽  
Compaction Characteristics ◽  
Practical Applications ◽  
Fine Grained ◽  
Practical Procedure ◽  
Fine Grained Soil

This study aims at modeling the compaction characteristics of fine-grained soils blended with sand-sized (0.075–4.75 mm) recycled tire-derived aggregates (TDAs). Model development and calibration were performed using a large and diverse database of 100 soil–TDA compaction tests (with the TDA-to-soil dry mass ratio ≤ 30%) assembled from the literature. Following a comprehensive statistical analysis, it is demonstrated that the optimum moisture content (OMC) and maximum dry unit weight (MDUW) for soil–TDA blends (across different soil types, TDA particle sizes and compaction energy levels) can be expressed as universal power functions of the OMC and MDUW of the unamended soil, along with the soil to soil–TDA specific gravity ratio. Employing the Bland–Altman analysis, the 95% upper and lower (water content) agreement limits between the predicted and measured OMC values were, respectively, obtained as +1.09% and −1.23%, both of which can be considered negligible for practical applications. For the MDUW predictions, these limits were calculated as +0.67 and −0.71 kN/m3, which (like the OMC) can be deemed acceptable for prediction purposes. Having established the OMC and MDUW of the unamended fine-grained soil, the empirical models proposed in this study offer a practical procedure towards predicting the compaction characteristics of the soil–TDA blends without the hurdles of performing separate laboratory compaction tests, and thus can be employed in practice for preliminary design assessments and/or soil–TDA optimization studies.

Physical and Mechanical Properties of Fine-Grained Soil in the Zhejiang-Fujian Coastal Area, China

2011 ◽  
Vol 29 (4) ◽  
pp. 333-345 ◽  
Author(s):  
Yuan-Qin Xu ◽  
Pei-Ying Li ◽  
Ping Li ◽  
Le-Jun Liu ◽  
Cheng-Xiao Cao ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Coastal Area ◽  
Physical And Mechanical Properties ◽  
Fine Grained ◽  
Fine Grained Soil

scholarly journals Centrifuge testing of soil–structure interaction effects on cyclic failure potential of fine-grained soil

2021 ◽  
pp. 875529302098197
Author(s):  
Jason M Buenker ◽  
Scott J Brandenberg ◽  
Jonathan P Stewart
Keyword(s):  
Soil Structure ◽  
Interaction Effects ◽  
Soil Structure Interaction ◽  
Centrifuge Testing ◽  
Geotechnical Centrifuge ◽  
Structure Interaction ◽  
Fine Grained ◽  
Stiffness Properties ◽  
Fine Grained Soil ◽  
Strip Footings

We describe two experiments performed on a 9-m-radius geotechnical centrifuge to evaluate dynamic soil–structure interaction effects on the cyclic failure potential of fine-grained soil. Each experiment incorporated three different structures with a range of mass and stiffness properties. Structures were founded on strip footings embedded in a thin layer of sand overlying lightly overconsolidated low-plasticity fine-grained soil. Shaking was applied to the base of the model container, consisting of scaled versions of recorded earthquake ground motions, sweep motions, and step waves. Data recorded during testing were processed and published on the platform DesignSafe. We describe the model configuration, sensor information, shaking events, and data processing procedures and present selected processed data to illustrate key model responses and to provide a benchmark for data use.

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