Soil Behavior

A new approach is developed to determine the shear wave velocity in saturated soft to firm clays using measurements of the liquid limit, plastic limit, and natural water content with depth. The shear wave velocity is assessed using the site-specific variation of the natural water content with the effective mean stress. Subsequently, an iterative process is envisaged to obtain the clay stiffness and strength parameters. The at-rest earth pressure coefficient, as well as bearing capacity factor and rigidity index related to the cone penetration test, is also acquired from the analyses. Comparisons are presented between the measured clay parameters and the results of corresponding analyses in five different case studies. It is demonstrated that the presented approach can provide acceptable estimates of saturated clay stiffness and strength parameters. One of the main privileges of the presented methodology is the site-specific procedure developed based on the relationships between clay strength and stiffness parameters, rather than direct correlations. Despite of iterative processes, the presented approach can be easily implemented using a simple spreadsheet, benefiting both geotechnical researchers and practitioners.

The authors should be commended for presenting such an innovative approach to the estimation of the collapse potential in unsaturated soils. This is a pioneering work that sets the basis for further developments on the use of pressuremeter tests for the mechanical characterization of unsaturated soils in the framework of advanced constitutive models. This area has not been adequately investigated to date, mainly due to the lack of a methodology for pressuremeter tests in unsaturated soils and the complexity of constitutive models. The present discussion intends to offer the opportunity for a debate with the authors on some

The deep foundation is characterized by the transfer of energy from the structure to the ground base, leading to the development of long deformation effects. The concepts used in practice by superpositioning transfer as a function of both the friction on the skin surface and the back resistance demonstrates a deficiency resulting from the development of long-term deformations. Cyclic loading conditions are observed, as a consequence of the development of the peptization of the dispersion system and its auxetic behavior, the formation of strain processes, which leads to the redistribution of forces in the direction-reduction of the component of the skin friction at the expense of the peak-production of the pile bottom. Over the past few decades, a series of field test procedures in full-scale piles have been assembled in a natural environment of continuous update of the standardization base. Standard procedures are developed in a range of studies depending on the main working pile mechanism and consider four basic approaches for the testing of compressive load-fast, static with one or more loading cycles, bidirectional and dynamic tests. Numerical methods require consideration of model parameters in the context of the soil-pile interaction mechanism, examination of soil parameters and laboratory and in-situ methods of determination in the context of the strain level. Current studies have been proposed for small scale pile models serving as a verification procedure for the implementation of predictive analytical techniques.

Die Planung und Ausführung von tiefen Baugruben in weichen Böden im innerstädtischen Bereich ist für alle Beteiligten eine große Herausforderung. In diesem Beitrag wird die Herstellung einer 8 m tiefen Baugrube mit unmittelbarer Nachbarbebauung in Konstanz vorgestellt. Hierzu werden umfangreiche Messergebnisse gezeigt, die im Rahmen der bei Baugruben in weichen Böden unverzichtbaren Beobachtungsmethode erfasst wurden, und mit den Ergebnissen einer numerischen Analyse unter Berücksichtigung der räumlichen und zeitabhängigen Effekte verglichen. Darüber hinaus werden die erforderlichen Nachweise für den Grenzzustand der Tragfähigkeit unter Berücksichtigung der komplexen Baugrund-Tragwerk-Interaktion präsentiert. Insbesondere wird ein modifizierter Ansatz zur Berechnung der Aufbruchsicherheit einer verankerten Baugrubensohle nach den Vorgaben des Eurocodes EC7-1 in Anlehnung an die Empfehlungen des Arbeitskreises „Baugruben“ der Deutschen Gesellschaft für Geotechnik vorgestellt.
Die Baugrube mit einem annähernd quadratischen Grundriss wurde im Jahr 2008 in weich-breiigem Seeton mit zwei Untergeschossen hergestellt. Als Verbauwand wurde eine eingepresste Spundwand verwendet, die in einer Höhe von –1,80 m durch einen oberen Aussteifungsring aus einer Gurtung mit diagonalen Ecksteifen und mit einer abschnittweise hergestellten Unterbetonsohle in einer Tiefe von –7,80 m ausgesteift wurde. Die räumlichen Einflüsse der Baugrund-Tragwerk-Interaktion, die für dieses Projekt durch den Einbau einer rautenförmigen oberen und unteren Aussteifung und den abschnittweisen Einbau der Betonsohle bestimmt wurden, konnten in einer zweidimensionalen numerischen Analyse mit Mobilisierungsfaktoren und unter Berücksichtigung der spannungspfadabhängigen Steifigkeit des Seetons zutreffend erfasst werden.
Dieses Ausführungsbeispiel einer tiefen Baugrube in weichen Böden verdeutlicht besonders die Wichtigkeit eines umfangreichen begleitenden Messprogramms im Hinblick auf die Anwendungsgrenzen der Finiten Elemente Methode bei Verwendung derzeit kommerziell verfügbarer höherwertigerer Stoffgesetze. In dem Beitrag wird darüber hinaus eine Methode zur Berücksichtigung der spannungspfadabhängigen Steifigkeit von weichen Böden vorgestellt.

The undrained response of cohesive soils is of paramount importance in geomechanics and it has been modelled extensively for the last 50 years. In comparison, drained behaviour of clays has received only modest attention. Drained and undrained behaviour is significantly affected by past consolidation stress history. This paper evaluates the capabilities of the MIT-S1 effective stress model, described in a companion paper, for predicting the anisotropic stress-strain-strength behaviour of clays. The paper illustrates the selection of model parameters for Lower Cromer Till, using data from standard types of laboratory tests. Comparison of model simulations with measured response for Lower Cromer Till and Boston Blue Clay illustrate model capabilities. The work focuses initially on comparisons of model predictions with measurements from undrained triaxial and plane strain tests on initially K 0 -consolidated specimens. Comparisons with measured data from undrained shear tests performed in different modes of shearing for LCT and BBC show that the model: (a) gives excellent predictions of maximum shear stress conditions and accurately describes the non-linear shear stress-strain behaviour; (b) accurately describes the anisotropic shear stress-strain-strength conditions for different consolidation stress histories; and (c) gives realistic description of mobilized friction angles, especially at large OCR's. The paper then focuses on the effects of consolidation stress history for isotropically consolidated specimens of resedimented Lower Cromer Till and Boston Blue Clay. Finally, the paper compares model predictions for drained shear tests on K 0 and isotropically consolidated specimens with overconsolidation ratios, OCR410; used to evaluate particular aspects of the critical state framework of soil behaviour. Overall, the model gives excellent predictions of the effect of initial anisotropy and overconsolidation stress history on the shear stress-strain and volumetric behaviour of clays.

This paper represents a new advance in the study of engineering properties and material applications of phyllite clays. Considering their potential use as construction materials for structures subjected to low stress levels, this laboratory research investigated the stabilization and improvement in engineering properties of a Spanish phyllite clay achieved by the addition of 3, 5 and 7 wt.% lime. Geotechnical properties investigated include the consistency limits, compaction, California Bearing Ratio, swelling potential and water-permeability. The phyllite clay–lime mixtures had good compaction properties and very to extremely low permeability-coefficient values, with a semi-logarithmic correlation between increasing permeability and increasing proportion of lime additive. The addition of 3 wt.% lime was sufficient to reach the index of capacity amble specified in the Sheet of Technical General Prescriptions for Works of Roads and Bridges PG–3 (Spanish Highways Agency, 2008), significantly reducing the plasticity index value, with the compacted mixture undergoing no swelling under soakage. The required pavement thicknesses for the raw phyllite–clay material and the phyllite clay–lime mixtures are compared and discussed. Potential applications for phyllite clay–lime mixtures include for pavements/road sub-grade, earth construction, building materials and for impermeabilization purposes.

Excavations in soft soils in particular in urban environments with adjacent neighbouring buildings are always subjected to deformations that are not fully avoidable. The soil-structureinteraction of excavations in soft soils is dependent on many factors. A classification of these factors that influence the deformation behaviour depending on the degree of designer interference dealt with in chapter 2. The focus of this research work is to examine the uncontrollable factors that affect the deformation behaviour based on the above classification. The ground conditions, in general, and the material properties of the soft soils in particular, are responsible primarily for the deformation behaviour. For this reason, the material behaviour of soft soils has been scientifically studied using experimental and numeric methods taking into account characteristic stress conditions that arise during excavation. The factors that are under designer control, e.g. support system and its stiffness, the factors that are partially under designer control, such as the method and quality of support construction, and the construction period are also analysed taking into account the time and stress path dependent material behaviour of the soil.
The research work is organised in three core areas which are developed one up on the other. Using excavation model tests, a numerical parameter study of three idealized excavations, and stress path controlled element tests, the above mentioned factors are examined. The time and stress path dependent material behaviour can be generally analysed and validated using a numerical analysis of three practical case studies based on a method that considers the stress path dependent stiffness. This method is devolped and explained within this thesis. Two of the practical projects had been accompanied by the author in the framework of this research work during the construction phase and one starting from the design phase.

India is agriculture sector, on either side, is losing ground every day, affecting the ecosystem's output capacity. In order to restore vitality and put agriculture back on a path of higher growth, there is a growing need to resolve the issue. A large-scale agricultural system necessitates a great deal of upkeep, knowledge, and oversight. The IoT is a network of interconnected devices that can transmit and receive data over the internet and carry out tasks without human involvement. Agriculture provides a wealth of data analysis parameters, resulting in increased crop yields. The use of IoT devices in smart farming aids in the modernization of information and communication. For better crop growth moisture, mineral, light and other factors can be assumed. This research looks into a few of these characteristics for data analysis with the goal of assisting users in making better agricultural decisions using IoT. The technique is intended to help farmers increase their agricultural output.

THIS IS NATURE SIGNALING THE END OF DUALITY 
THIS IS HUGE - CHANGE THE ENTIRETY OF CREATION - NO DUALITY ANYWHERE.
IT IS VERY CLEARLY A PREDETERMINED ADVANCEMENT OF HUMAN CONSCIOUSNESS - THIS BUBBLE IS TOO WELL DESIGNED - EUPHORIA CANCELS KARMA

Soil classification systems represent powerful tools not only to facilitate soil identification, but also to predict its possible behavior. While the use of arbitrary standards based on particle size distribution may be applicable to coarse-grained soils, those approaches based exclusively on textural principles are ineffective in classifying fine-grained soils, where clay content and its mineralogy dictate the general properties. In this sense, the measurement of plasticity represents a more appropriate parameter than particle size. This fact has led various authors and technical committees to develop fine-grained soil classification systems based on plasticity. However, the disparity of criteria makes it necessary to review them in order to glimpse the weaknesses and strengths of each of them. This paper includes the review of the six main existing proposals together with the possible variants arising from them: Casagrande (1947)-Unified Soil Classification System (USCS), American Association of State Highway and Transportation Officials (AASHTO), Federal Aviation Agency (FAA), Saito and Miki (1975), Polidori (2003, 2007, 2009) and Moreno-Maroto and Alonso-Azcarate (2017, 2018) classification charts, which are designed on the basis of Atterberg limits. After conducting a complete and thorough examination, it is shown that although the Casagrande (1947)-USCS approach is the most widely known, of all the proposals examined, only that of Moreno-Maroto and Alonso-Azcarate (2017, 2018) is based on well-founded criteria, presenting a strong predictive capacity, as well as being simple, precise and adaptable to needs.

Structures are normal or special; these are precious part and are promptly associated with living as well as non living things. Sometimes minute fault inside the structure might affect whole body and it would lead to collapse the structure which might create a significant loss of property and human beings too. So, increased awareness of structural Health Monitoring Techniques (SHM) gives an idea and remedies for the concerned defect due to aging, deterioration and fault during construction. Previous day's people used just a visual inspection for defect detection but extreme and worst damage in infrastructure leads to invent new technologies for the recognition of new methods on Structural Health

For the derivation of the axial resistance of driven sheet piles empirical calculation procedures are given in the recommendations of the working groups "Ufereinfassungen" (EAU, 2004) and "Baugruben" (EAB, 2006), which does not always lead to consistent results. Hence, sev-eral static and dynamic load tests on driven sheet piles were evaluated using statistical meth-ods and the resulting characteristic axial resistance are verified on the basis of the approach of the working group "Pfähle" (EA-Pfähle, 2007). The examined load tests had been carried out in North Germany, hence the resulting characteristic axial resistance of driven sheet piles are first presented as preliminary result for North German underground conditions and compared with the present empiric calculation procedures. Further investigations on axial resistance of driven sheet piles, especially the consideration of restraining effects in dependence on the cross section of the sheet pile profile, are running at the present at the University of Kassel.

Clayey soils are usually stiff when they are dry and give up their stiffness as they become saturated. Soft clays are associated with low compressive strength and excessive settlement. This reduction in strength due to moisture leads to severe damages to buildings and foundations. The soil behavior can be a challenge to the designer build infrastructure plans to on clay deposits. The damage due to the expansive soils every year is expected to be $1 billion in the USA, £150 million in the UK, and many billions of pounds worldwide. The damages associated with expansive soils are not because of the lack of inadequate engineering solutions but to the failure to identify the existence and magnitude of expansion of these soils in the early stage of project planning. One of the methods for soil improvement is that the problematic soil is replaced by suitable soil. The high cost involved in this method has led researchers to identify alternative methods, and soil stabilization with different additives is one of those methods. Recently, modern scientific techniques of soil stabilization are on offer for this purpose. Stabilized soil is a composite material that is obtained from the combination and optimization of properties of constituent materials. Adding cementing agents such as lime, cement and industrial byproducts like fly ash and slag, with soil results in improved geotechnical properties. However, during the past few decades, a number of cases have been reported where sulfate-rich soils stabilized by cement or lime underwent a significant amount of heave leading to pavement failure. This research paper addressed the some fundamental and success soil improvement that used in civil engineering field.

Nombre:__________________________________ Código:____________ 1. Defina los siguientes conceptos: Suelo, Roca 2. ¿Cuáles tipos de rocas hay? ¿Cómo se diferencian? 3. De 3 ejemplos de cada tipo de roca según su origen 4. ¿Cómo se califican los suelos según su origen? ¿Qué factores determinan el tipo de suelo que se forma? 5. Cite los 6 horizontes (Grados) de meteorización de una roca 6. ¿Cuáles son los 6 tipos de suelo según su origen? ¿Qué propiedades tiene cada uno? 7. ¿Cómo se clasifican los suelos según su tamaño? ¿Cuáles son los rangos numéricos de tamaño (Tamaños del tamiz) entre cada tipo de suelo?

In the scope of this study, selection process of ground improvement methods for soils, which has bearing capacity, settlement, liquefaction, permeability, stability, swelling or subsidence problems, are investigated. Soil improvement methods are investigated in detail. All improvement methods can be classified as surface and deep according to depth, mechanical, hydraulical, physical, chemical, biotechnical and reinforcement according to the method of application, for clayey soils, for sandy soils and for all soils according to the soil types, and reinforcement, improvement and treatment according to application for tunnels, underwater constructions, historical buildings, and other superstructure and infrastructure projects. In this study, soil improvement methods are classified according to depth and the soil improvement methods are explained under two main headings as surface and deep soil improvement methods that improve bearing capacity, settlement, liquefaction, permeability, stability, swelling and subsidence problems. Under surface ground improvement and deep ground improvement methods, improvement by reinforcement, improvements with admixtures, surface drainage, surface compaction methods are mentioned as surface improvement methods and biotechnical, deep dynamic compaction, deep drainage, deep mixing, deep dynamic modification, electrical signal compaction, grouting, hydro-blasting compaction, thermal treatment, improvement piles, jet grouting, sand compaciton pile (SCP), microbic methods, blasting, stone column were mentoined as deep improvement methods. Moreover, most used methods, which are jet grouting, cement grouting and stone column, were examined in detail.
Commonly used ground improvement methods jet grouting, cement grouting and stone column applications’ effects on soil behaviour were investigated. Improvement effects of these three methods on same soils were estimated. Jet grouting, cement grouting and stone column methods were modelled for a site where bored piles were applied. On this site, soil profiles which have bearing capacity and potential settlement problems were determined according to the available soil investigation report. Jet grouting, cement grouting and stone column materials were designed for these profiles. All these design parameters should be checked on site. Design parameters of jet grouting, cement grouting and stone column materials were used in empirical and Plaxis software analysis which use finite element methods. All the analysis were done on Profile 1, Profile 2 and Profile 3 which are determined as having porential bearing capacity and settlement. Profile 1 includes low plasticity clay and clayey gravel, Profile 2 includes high plasticity clay, low plasticity silt and clayey sand, and Profile 3 includes silty and clayey sand. First, lengths of columns and piles were optimized for these three soil profiles. Jet grouting, cement grouting and stone column applications were investigated in 3.4 m and 13 m excavation depths, different column lenghts, and 3 D (%8.7), 2 D (%19,6) and 1,5 D (%34,9) column spacings (improvement rates) whereby empirical and numerical analysis using Plaxis program column and composite soil, Terzaghi and Meyerhof bearing capacity theories and Bowles settlement theory. According to this, each soil improvement methods has an effective column length that change with soil samples and lengths. Even though, almost all the improvement methods’ bearing capacity and settlements were affected positively with increase of improvement ratio, however, there were also rare negative effects like settlement increase of stone column in sandy soil.
In terms of bearing capacity, stone column method gave better results than jet grouting and cement grouting applications. Although, in the application of stone column, in sand, bearing capacity has increased, increase of bearing capacity for jet grouting application gave far better results. Cement grouting, which is applicable only to sand on Profile 3, increased bearing capacity significantly. However, the effect of cement grouting on the bearing capacity was less than stone column and jet grouting applications.
Furthermore, jet grouting application affect settlements far possitively for clayey, silty and even sandy soils than the other methods, moreover, the settlement problem beneficially. Stone column method, which is applied through substitution is not rigid, and cause less settlements for clayey and silty soils, but settlements were increased in sandy soils. This situation could be better when alternative compacted stone column methods are applied. Moreover, cement grouting affected settlements well, but it could not be as much as jet grouting effects.
On the other hand, there were distinct results according to analysis types. It was observed that calculated empirical bearing capacity values were higher than the one’s found the other methods. Moreover, bearing capacity that calculated according to composite soil theory is higher than calculated value by Plaxis program. Also, empirical calculation of settlements is lower than calculated value by Plaxis program. Bearing capacity of stone columns calculated by using the composite soil theory gave high bearing capacity values on the internal friction angle is high. Bowles settlement theory results gave less settlement values than the one calculated by Plaxis program. Plaxis column calculations can be considered better due to the reason that column can be evaluated separate or group.
In addition, the stone column usage in the clay and silt soils gave better results than sand. As long as cement injection can be applied, it has been observed that it contributes to the bearing capacity of loose sands and improved to settlement behaviour. Also, jet grouting method contributed significantly to settlements including clayey, silty and sandy soils, however, it did not demonstrate a good performance in bearing capacity. Jet grouting method has been shown to contribute positively to the bearing capacity on clayey and silty soils, but it has not been able to make much contributions to settlement. As a result, jet grouting method can be effective in all soil types, and it can make significant contributions to settlements in all types of soil and has a positive effect on all soil types. Stone column method has positive effects on settlements on clayey and silty soils and contributes significantly to bearing capacity in all types of soils. Although, cement grouting method has narrow application area, it contributes to the bearing capacity and settlement of loose sand.
Finally, only jet grouting application has provided sufficient bearing capacity and limit settlement values in profile 3. While the jet grouting improvement was insufficient in profile 1 and profile 2, and stone column and cement grouting were not sufficient in all profiles. The bored pile method applied can be used as an alternative to soil improvement methods under high superstructure loads. Soil improvement can be preferred for soils that are under low loads.

In this thesis study, dynamic soil behavior analysis is performed and liquefaction potential is investigated in a new region where high rise buildings are being built in Bayraklı District.
First of all, soil profiles are constituted from borehole data of the region and by using convenient software for student use named as EduShake, dynamic soil behavior analysis are performed for the region. Results are tabled and discussed.
In the study area, ground water table is quite high and many levels of sand and silt type of soils exist in soil profiles. These factors show the necessity and the importance of liquefaction potential analysis for the region.
Lastly, data from dynamic behavior and liquefaction potential analyses are interpreted according to Specification for Buildings to be Built in Seismic Zones (2007).

The Standard Penetration Test (SPT) is the most commonly used in-situ test in Bangladesh, while the Cone Penetrations Test (CPT) is becoming popular day by day for using reliable and cost effective design template. Geotechnical Engineers are more familiar with design procedures based on SPT results. As a result, many Engineering projects it is most common to use both CPT and SPT together for subsoil investigation. However, it is not cost effective to perform the both test. It is crucial to identify a correlation between the results of SPT (N) value and CPT test results based on field measurements to convert CPT to SPT result or vice versa. This paper first reviews existing correlations between the results of both SPT and CPT in the literature. The existing correlations depend on grain size, fines content or the soil behaviour type index, I c. This paper uses the results of soil investigations in Ten (10) major sites in Dhaka city where results of both SPT and CPT, together with grain size distributions are available. The data compiled by the current research of proposed correlations for q c (cone bearing resistance), N 60 (N-values corresponding to hammer efficiency of 60%) and others soil parameters shows similar trend as presented by earlier researchers.

A serious problem has been discovered in the interface formulation in one of the most popular finite element software programs used in geotechnical practice. This paper analyses the problem of interface formulation which is not in agreement with the definition given in program manuals. Problem explained appears to have been solved in the most recent version, but the author finds it important to discuss the implications of this problem, because there are so many investigation conclusions given in the recent past without being aware of this problem. A simple example of sliding block on elastic soil is used for this investigation and the results with discussions are presented, with intimate details of the computational model.

The soils of Jinka in Southern Ethiopia were studied based on the detail works on soil pit description, characterizing and classification following the FAO and USDA guidelines. For this, along with the topo-sequence and landscape, six soil profiles were opened on an area of 100 ha of research field to make them suit for sustainable soil management practices. The soils were generally described as dark reddish brown to very dark brown and deep. These soils were characterized as slightly (4.87) to moderately acidic (6.18). The OC and available phosphorus were found to range from low to medium. All micronutrients were found to be highly associated with lower soil reaction. These soils group can be classified as Cambisols. Therefore, amending the soil with lime based on exchangeable acidity, essential and deficient nutrients will be vital for supplying food and feed crops in the region. However, continuous assessment of the nutrient status at every five to seven years is necessary to make sure that the soil quality is maintained.

The article presents a set of general relationships for permanent volumetric strain from cyclic
loading. These relations can be used to predict earthquake induced settlements on granular soils,
with direct application to shallow foundations. Volumetric strain is calculated at the end of each
loading cycle for the following cases: drained or undrained conditions, isotropic initial stress state
(σ΄1=σ΄3, e.g. free field) or anisotropic initial stress state (σ΄1≠σ΄3, e.g. initial static shear), constant
cyclic stress or constant cyclic shear. The variables of the general relations are based on statistical
analysis of experimental data from drained cyclic triaxial tests and relate directly to the initial stress
or strain state and density of the soil element. The accuracy of predictions is examined through
comparison with a) experimental data b) well established charts from other researchers and c)
measured settlements due to earthquake, from reported cases histories.

_________________________________________________________________________________ ABSTRACT— Clays in general and expansive soils in particular have been a major concern to geotechnical engineers for many years. Moisture variations produce big volume changes in these types of soils. Several factors like amount and type of clay minerals, soil structure, dry density, confining pressure, moisture content and climate changes influence the amount of swell and shrinkage. These volume changes finally result in serious damage to the various structures including pavements. In addition, clayey soils are usually stiff when they are dry and give up their stiffness as they become saturated. Soft clays (i.e. illite/kaolinite/ montmorillonite) are associated with low compressive strength and excessive settlement. This reduction in strength due to moisture leads to severe damages to buildings and foundations.

The ground is a natural grand system; it is composed of myriad constituents that aggregate to form several geologic and biogenic systems. These systems operate independently and interplay harmoniously via important networked structures over multiple spatial and temporal scales. This paper presents arguments and derivations couched by the authors, to first give a better understanding of these intertwined networked structures, and then to give an insight of why and how these can be imitated to develop a new generation of nature-symbiotic ground engineering techniques. The paper draws on numerous recent advances made by the authors, and others, in imitating forms (e.g. synthetic fibres that imitate plant roots), materials (e.g. living composite materials, or living soil that imitate fungi and microbes), generative processes (e.g. managed decomposition of construction rubble to mimic weathering of aragonites to calcites), and functions (e.g. recreating the self-healing, self-producing, and self-forming capacity of natural systems). Advances are reported in three categories of Materials, Models, and Methods (3Ms). A novel value-based appraisal tool is also presented, providing a means to vet the effectiveness of 3Ms as standalone units or in combinations.

"FOR CITATIONS:
Salem, H.S., 2000. Poisson's ratio and the porosity of surface soils and shallow sediments, determined from seismic compressional and shear wave velocities. Geotechnique (Institute of Civil Engineers (ICE)). 50-L (4), August: 461-463. (A Scholarly Paper Published in International Journal).
http://www.icevirtuallibrary.com/content/article/10.1680/geot.2000.50.4.461

Abstract:
Propagation of compressional (P) and shear (S) waves through
soils, sediments and rocks is governed by various factors,
including:
(a) lithological properties, including formation texture (size, shape, type, packing, sorting and distribution of grains), kind and amount of clays, compaction, consolidation and cementation; and
(b) physical properties, including porosity, permeability, density,
anisotropy, kind of saturant and degree of saturation, solid-fluid coupling, pressure and temperature;
(c) elastic (mechanical) properties, including bulk modulus (incompressibility), shear modulus  (rigidity), Young's `elasticity'
modulus, Lame's constant, and Poisson's ratio.

Poisson's ratio is a measure of the transverse strain or
contraction to longitudinal strain or extension resulting from a
change in normal stress under compression or dilatation. A
change in the wave propagation from one lithology to another
or from an unsaturated to a saturated medium leads to variations
in the value of the Poisson's ration from 0 (indicating a considerable change in volume) to 0.5 (indicating no volumetric change, corresponding to fluids). Also, the Poisson's ratio can have negative values, and these indicate certain properties.
Poisson's ratio has been effectively used in engineering, and in groundwater and hydrocarbon investigations. ""

Observation and numerical modeling of MSE test wall is presented here. The 6m wide and 3.2m high wall with 10cm thick precast concrete face elements and reinforcement length of 2.15m was built on construction site of Motorway 5C in Bosnia and Herzegovina. Welded wire mash Q335 was used as reinforcement. Compared to other MSE test walls, the presented work is unique due to the choice of backfill material consisting of course crushed stone aggregate ranging from ~0-100mm in size whereas most of other published studies used sandy backfill. Two weeks after the construction, the top of the wall was loaded with additional overburden weight 1,5m in height (~30 kPa). The forces in reinforcement were measured with a series of embedded sensors and deformation with an inclinometer installed in the middle of the wall length, including geodetic survey of wall face. Experimentally observed results are compared to the analysis results obtained from numerical model created using Plaxis software.

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Abstract: In this study, the potential of pulverized waste tires (PWTs), either on their own or mixed with soil (well graded sand), to act as adsorptive fill materials was evaluated by conducting laboratory tests for accessing their adsorption and geotechnical properties. PWT (0, 5, 10, 15, 25, and 100 wt%) was mixed with soil to evaluate the removal of benzene, toluene, ethylbenzene, and xylene (BTEX) components and two heavy metal ions (Pb2+ and Cu2+). Adsorption batch tests were performed to determine the equilibrium sorption capacity of each mixture. Subsequently, compaction, direct shear, and consolidation tests were performed to establish their geotechnical properties. The results showed that BTEX had the strongest affinity based on the uptake capacity by the soil–PWT mixtures. The adsorption of BTEX increased for greater PWT content, with pure PWT having the highest adsorption capacity toward BTEX removal: uptake capacities for xylene, ethylbenzene, toluene, and benzene were 526, 377, 207 and 127 µg/g sorbent, respectively. Heavy metal removal was increased by increasing the amount of PWT up to 10 wt%, and then decreased beyond this ratio. Compacted soilePWT mixtures comprising 5–25 wt% PWT have relatively low dry unit weight, low compressibility, adequate shear capacity for many loadbearing field applications, and satisfactory adsorption of organic/inorganic contaminants, such that they could also be used as adsorptive fill materials.

The soils of Jinka in Southern Ethiopia were studied based on the detail works on soil pit description, characterizing and classification following the FAO and USDA guidelines. For this, along with the topo-sequence and landscape, six soil profiles were opened on an area of 100 ha of research field to make them suit for sustainable soil management practices. The soils were generally described as dark reddish brown to very dark brown and deep. These soils were characterized as slightly (4.87) to moderately acidic (6.18). The OC and available phosphorus were found to range from low to medium. All micronutrients were found to be highly associated with lower soil reaction. These soils group can be classified as Cambisols. Therefore, amending the soil with lime based on exchangeable acidity, essential and deficient nutrients will be vital for supplying food and feed crops in the region. However, continuous assessment of the nutrient status at every five to seven years is necessary to mak...

This paper presents a methodology to compute bending moments and shear forces, etc., in geosynthetic-reinforced pavement on expansive soils. The geosynthetic-reinforced pavement, subjected to the heave/shrinkage-induced vertical displacement caused by the volume change of expansive subgrade soils, was formulated by following the Timoshenko beam theory. The virtual load method (VLM) was developed by applying a virtual load on the pavement to make the beam deflection equivalent to the heave/shrinkage-induced vertical displacement. The unknown virtual load was expressed as a Fourier series, and the Fourier constants were determined by employing the inverse theory for the identification of material parameters. As a case study, the virtual load method was applied to investigate the effect of geosynthetics on the research road FM-2 in Texas, USA. The geosynthetics in the pavement functioned as a reinforcement to reduce the pavement damage caused by the seasonal swell and shrinkage of the expansive subgrade soils.

Given its apparent limitations, various attempts have been made to develop alternative testing approaches to the standardized rolling-thread plastic limit (PLRT) method (for fine-grained soils), targeting higher degrees of repeatability and reproducibility. Among these, device-rolling techniques, including the method described in ASTM D4318/AASHTO T90 standards, based on original work by Bobrowski and Griekspoor (BG) and which follows the same basic principles as the standard thread-rolling (by hand) test, have been highly underrated by some researchers. To better understand the true potentials and/or limitations of the BG method for soil plasticity determination (i.e., PLBG), this paper presents a critical reappraisal of the PLRT–PLBG relationship using a comprehensive statistical analysis performed on a large and diverse database of 60 PLRT–PLBG test pairs. It is demonstrated that for a given fine-grained soil, the BG and RT methods produce essentially similar PL values. The 95% lower and upper (water content) statistical agreement limits between PLBG and PLRT were, respectively, obtained as –5.03% and + 4.51%, and both deemed “statistically insignificant” when compared to the inductively-defined reference limit of +/– 8% (i.e., the highest possible difference in PLRT based on its repeatability, as reported in the literature). Furthermore, the likelihoods of PLBG underestimating and  overestimating PLRT were 50% and 40%, respectively; debunking the notion presented by some researchers that the BG method generally tends to greatly underestimate PLRT. It is also shown that the degree of underestimation/overestimation does not systematically change with changes in basic soil properties; suggesting that the differences between PLBG and PLRT are most likely random in nature. Compared to PLRT, the likelihood of achieving consistent soil classifications employing PLBG (along with the liquid limit) was shown to be 98%, with the identified discrepancies being cases that plot relatively close to the A-Line. As such, PLBG can be used with confidence for soil classification purposes.

The thesis focuses on three different areas: development of constitutive models for unsaturated soils, improvement of the finite element code “Compass” for coupled flow-deformation analysis involving unsaturated soils and application of the improved code to the simulation of pressuremeter tests in unsaturated soils.
On the constitutive side, a unique relationship is proposed between degree of saturation, suction and specific volume by introducing dependency on specific volume in the simplified van Genuchten equation. This is a significant improvement over the common assumption of a state surface expression for degree of saturation. If combined with an elasto-plastic stress-strain model predicting the variation of specific volume, the proposed relationship is capable of reproducing irreversible changes of degree of saturation and changes of degree of saturation experimentally observed during shearing. Predictions show very good agreement with experimental results from tests on compacted Speswhite Kaolin published in the literature.
On the numerical side, a number of changes to the code “Compass” have been performed. The new relationship for degree of saturation is implemented in the code and the implementation is validated against three benchmark problems. Use of the new relationship for degree of saturation results in significantly different predictions to those obtained if a conventional state surface expression for degree of saturation is used (as present in the original code).
Implementation of the water and air continuity equations in “Compass” has been corrected by expressing these equations in terms of flux velocities relative to the soil skeleton. This is the form in which the equations should be expressed if they are to be combined with Darcy’s law for liquid and gas flows. The simulation of a notional laboratory test shows that the incorrect combination of Darcy’s law with absolute flux velocities, as present in the original code, causes significant errors.
The convergency algorithm at constitutive level employed in the code has been corrected by introducing residual flux terms in the two flow equations, analogous to residual forces in the equilibrium equation. These terms must be taken into account if a convergency algorithm for an elasto-plastic stress-strain model is used and the relationship assumed for variation of degree of saturation involves any dependency on net stresses. A numerical study of a notional laboratory test shows that omission of residual flux terms results in substantial errors and may cause failure to converge.
The plane_strain formulation of code “Compass” has been corrected by imposing the condition of nullity only on the out-of-plane component of the total strain rate vector instead of the out-of-plane component of each single contribution to the total strain rate, as was done in the original code. Such inconsistency, due to the history of development of finite element programs, also appears in other examples published in the literature. Numerical simulations of two types of bi-axial tests show that significantly different results are generally predicted by the correct and incorrect formulations, and also provide an explanation why this type of error was difficult to detect in codes implementing traditional models for saturated soils.
The potential of the enhanced version of code “Compass” for analysing boundary value problems is demonstrated by simulations of pressuremeter tests in unsaturated soil. This study also provides some initial insight into the interpretation of pressuremeter tests in unsaturated soil by simulating tests at different loading rates in a normally consolidated soil. The mechanical behaviour of the soil is represented by the elasto-plastic Barcelona Basic Model of Alonso, Gens and Josa (1990) while the variation of degree of saturation is modelled by the new relationship proposed in the thesis. The entire range of loading rates, from undrained to fully drained (with respect to liquid), is simulated. Relatively small changes of suction are predicted even in the fastest test and the computed cavity pressure-cavity strain relationships are all very similar regardless of loading rate. It may therefore be possible to model even rapid pressuremeter tests in unsaturated soils as a drained (constant suction) process. Further work is required to investigate the generality of this conclusion.