Soil Mechanics

A 61-m (200-ft) high FGD waste landfill over an existing fly ash impoundment is currently under construction. A concern was whether typical waste filling rates would be sufficient for static liquefaction of the impounded fly ash to occur. In this paper, data from a large test fill is used to assess the potential for static liquefaction of the impounded fly ash. The test fill comprised a 9-m (30-ft) high preload fill which was constructed using much higher fill placement rates than for typical waste filling. Excess pore pressures in the impounded fly ash were measured. The time history of filling and measured excess pore pressures were used to back-calculate the average vertical coefficient of consolidation of the impounded fly ash, a parameter that is representative of the drainage characteristics of the fly ash. As measured excess pore pressures were primarily the result of volumetric loading, an analysis was conducted to estimate undrained shear-induced excess pore pressures for a...

O objetivo deste trabalho foi avaliar o desenvolvimento aéreo e radicular de duas cultivares de milho (Zea mays L.), em solo submetido a quatro níveis de compactação. Utilizou-se um Latossolo Vermelho-Escuro distroférrico de textura média, em vasos montados com anéis de PVC sobrepostos, com diâmetro interno de 14,5 cm e altura de 35 cm. Os níveis de compactação utilizados em subsuperfície foram caracterizados pelas densidades do solo de 1,28, 1,42, 1,56 e 1,69 Mg m³. As cultivares de milho foram o híbrido AG-5011 e a variedade Sol da Manhã. Aos 40 dias após a emergência das plantas, determinaram-se as massas da matéria seca da parte aérea e das raízes, a densidade do comprimento radicular e o diâmetro médio radicular. A compactação do solo comprometeu o desenvolvimento das plantas de milho híbrido e da variedade na mesma intensidade. Apesar de alterar a distribuição do sistema radicular ao longo do perfil do solo, o impedimento físico em subsuperfície não diminuiu a produção total d...

This Research paper is a live study on the above mentioned title "Study on Open and Closed end Pile Foundation". Steel pipe piles are highly durable, provide reliable foundation, have shorter construction period and can be driven into such medium where other piles can't like boulder medium. Steel pipe piles are economical for long piles into deeps loose soil. Till now most of research has been directed towards the response of individual piles to vertical loads. Both the driving response and static bearing capacity of open-ended piles are affected by the soil plug that forms inside the pile during pile driving. In order to investigate the effect of the soil plug on the static and dynamic response of an open-ended pile and the load capacity of pipe piles in general, field pile load tests were performed on instrumented open-and closed-ended piles driven into sand. For the open-ended pile, the soil plug length was continuously measured during pile driving, allowing calculation of the incremental filling ratio for the pile.

This Research paper is a live study on the above mentioned title "Recycling of Concrete" This paper consist the introduction of recycled concrete aggregate with its uses and properties. Various test results on Recycled concrete aggregate also described. It also consist the difference between RCA and natural aggregate. The future recommendations are also discussed in addition. Keywords-Recycled Coarse Aggregate (RCA), Concrete Mix Design(CMD), Natural Aggregate(NA) I.

This Research paper is a live study on the above mentioned title "Study on Open and Closed end Pile Foundation". Steel pipe piles are highly durable, provide reliable foundation, have shorter construction period and can be driven into such medium where other piles can't like boulder medium. Steel pipe piles are economical for long piles into deeps loose soil. Till now most of research has been directed towards the response of individual piles to vertical loads. Both the driving response and static bearing capacity of open-ended piles are affected by the soil plug that forms inside the pile during pile driving. In order to investigate the effect of the soil plug on the static and dynamic response of an open-ended pile and the load capacity of pipe piles in general, field pile load tests were performed on instrumented open-and closed-ended piles driven into sand. For the open-ended pile, the soil plug length was continuously measured during pile driving, allowing calculation of the incremental filling ratio for the pile.

This Research paper is a live study on the above mentioned title “Recycling of Concrete” This paper consist the introduction of recycled concrete aggregate with its uses and properties. Various test results on Recycled concrete aggregate also described. It also consist the difference between RCA and natural aggregate. The future recommendations are also discussed in addition. Keywords—Recycled Coarse Aggregate (RCA), Concrete Mix Design(CMD), Natural Aggregate(NA)

Collapsible soils have considerable strength and stiffness in their dry natural state but settle dramatically when they become wet. This paper documents a low-cost, qualitative evaluation scheme using fuzzy set analysis to determine regional collapsibility based on subjective knowledge of the geological and geotechnical conditions and their uncertainty. The geological and geotechnical factors and their category were defined based on relevant literature. Each factor and category was then weighted or rated using linguistic terms developed from expert assessment. The linguistic data or information obtained from the assessments was represented and processed using fuzzy sets. To assess the criteria, 87 collapse potential tests were performed on undisturbed soil samples gathered from 27 different locations throughout Iran. It is shown that the geotechnical criteria predict soil collapsibility much better than the geological criteria.

Gravel-Clay mixtures are abundant materials in nature and are frequently used in certain civil engineering projects such as earth dams, levees and landfills. The advantage of using these soils lies in their low permeability owing to clay fraction along with the high shear strength due to the presence of the non-cohesive granular part. Karkheh dam is an example where these soils were used as the impervious core of the embankment. To date, little research has been carried out to investigate the performance of these soils, and therefore, their behavior under cyclic loading is still not well known. In order to investigate the cyclic behavior of gravel-clay mixtures, 51 cyclic and monotonic triaxial tests were performed on specimens with 11 different mixtures and under various confining pressures. Two different types of gravel, i.e. angular and round grains, were utilized to prepare specimens with the same gravel content in order to investigate the effect of the granule shape on the cycl...

A fiber reinforced soil behaves as a composite material in which fibers of relatively high tensile strength are embedded in a matrix of soil. Shear stresses in the soil mobilize tensile resistance in the fibers, which in turn imparts greater strength to the soil. In this paper a study on the influence of synthetic fibrous materials in improving the dynamic strength characteristics of a fine sandy soil is reported. The study is aimed at converting fibrous carpet waste into a value-added product for soil reinforcement. A series of stress controlled cyclic triaxial tests were carried out on fine sand specimens reinforced with randomly distributed carpet strips. The dynamic deformation properties of the reinforced sand are defined in terms of shear modulus and damping ratio. The effects of parameters such as fiber content and aspect ratio, number of cyclic loading and the level of confining pressure on the aforesaid parameters were investigated. The results clearly indicate the increase of damping ratio of reinforced samples in different confining pressure. The increase is more pronounced in higher fiber contents and aspect ratios.

Shear modulus and damping ratio are important input parameters in dynamic analysis. A series of resonant column tests was carried out on pure clays and sand-clay mixtures prepared at different densities to investigate the effects of aggregate content, confining stress, void ratio and clay plasticity on the maximum shear modulus and minimum damping ratio. Test results revealed an increase in the maximum shear modulus of the mixture with the increase in sand content up to 60%, followed by a decrease beyond this value. It was also found that the maximum shear modulus increases with confining stress, and decreases with void ratio. In addition, minimum damping ratio increases with sand content and clay plasticity and decreases with confining stress. Finally, on the basis of the test results, a mathematical model was developed for the maximum shear modulus.

Switzerland is exceptionally subjected to landslides; indeed, about 10% of its area is considered as unstable. Making this observation, its Department of the Environment (BAFU) introduces in 1997 a method to realize landslide hazard maps. It is routinely used but, like most of the ...

Approaches to model the behaviour of underground disposals for nuclear waste have traditionally assumed perfect contacts between the different materials. However interfaces between the materials may affect significantly the hydration process of the bentonite buffer and later act as preferential pathways for the migration of radionuclides. The paper presents an approach to model interfaces using contact finite elements. The influence of interfaces on the hydration kinetics of a bentonite buffer is highlighted.

Approaches to model the behaviour of underground disposals for nuclear waste have traditionally assumed perfect contacts between the different materials. However interfaces between the materials may affect significantly the hydration process of the bentonite buffer and later act as preferential pathways for the migration of radionuclides. The paper presents an approach to model interfaces using contact finite elements. The influence of interfaces on the hydration kinetics of a bentonite buffer is highlighted.

Ce rapport de thèse clôture pour moi une longue période passée à Grenoble et au laboratoire 3S. Dès 2001, j'ai été accueillie au laboratoire par Marc Boulon, Julien Hans et Olivier Buzzi pour un stage de quelques mois. Ce sont eux qui m'ont initié à la géomécanique et m'ont fait découvrir le milieu de la recherche. C'est donc tout naturellement que je suis venue voir Marc Boulon quand l'envie ma prise en 2003 de faire un Master puis une Thèse dans ce domaine. Avant d'entrer dans le vif du sujet, je souhaite tout particulièrement remercier Marc Boulon pour m'avoir initié à la géotechnique et pour m'avoir donné l'occasion de faire cette thèse, la dernière thèse de sa carrière. Et puis, bien évidemment je remercie très chaleureusement Yann Malécot pour l'avoir co-encadré. J'ai beaucoup apprécié ses méthodes de travail, la liberté qu'il m'a laissé dans l'organisation de ces recherches et ses encouragements nombreux et réguliers, qui m'ont toujours remonté le moral dans les moments difficiles. Enfin, je n'oublie pas Etienne Flavigny. Ses remarques, toujours pertinentes, ont été très bénéfiques à l'avancement de cette thèse. Mes plus sincères remerciements vont également aux membres du jury, qui ont accepté de relire et commenter cette thèse : Antonio Gens, Pierre-Yves Hicher, Félix Darve, ainsi que les différents invités : François Schlosser, Paul Bonnier et Youssef Hashash. Leurs remarques ont été à l'origine de discussions riches et passionnantes. Je souhaite également profiter de cette occasion pour remercier les membres de l'AUGC qui ont salué ce travail en me décernant le prix " René Houpert " 2007, des jeunes chercheurs en Génie Civil. Et puis, j'adresse un grand merci à Cino Viggiani, Richard Finno et Cecilia Rechea Bernal pour m'avoir donné l'occasion de passer quelques mois à l'université de Northwestern en 2005. J'ai beaucoup apprécié ce séjour, qui fut très intéressant et très instructif, aussi bien du point de vue scientifique que personnel. Cette collaboration fut à l'origine de nombreuses discussions, qui ont donné un élan particulier à cette thèse. Sans cette expérience, mon travail ne serait pas ce qu'il est aujourd'hui. Enfin j'ai une pensée pour tout ceux qui m'ont entouré au quotidien ces dernières années, mes parents, mon frère et ma famille, mais aussi mes amis, ainsi que tous les membres du laboratoire avec qui j'ai passé d'agréables moments. Plus particulièrement, je pense à Luisa et à Marcos, des passionnés de chaussettes et de fromages, à Wenjie, qui adore raconter des histoires drôles qui ne font rire que lui, à Luc, pour qui ma culture normande reste obscure, et aux nombreux autres thésards, anciens ou nouveaux, tels que Emmanuel, Florent, Stéphane et Jean-François, toujours prêts pour les pires âneries, et aussi Jessica, Gabriella, Hà, Elma, Cécile, Cédric, King, Julien, Thomas, Nicolas, Steve, Thanh, Luc, Lionel et Bastien, qui ont toujours su pimenter la vie du laboratoire. Enfin, pour finir, j'aimerai adresser une pensée spéciale à Jane et à Mark qui m'ont accompagné tout au long de cette thèse et qui aujourd'hui me manquent beaucoup. Je n'oublierai pas leurs innombrables facéties, leur joie de vivre et tous ces moments que nous avons passé ensemble.

To help minimize risk of high sinkage and slippage during drives and to better understand soil properties and rover terramechanics from drive data, a multidisciplinary team was formed under the Mars Exploration Rover (MER) project to develop and utilize dynamic computer-based models for rover drives over realistic terrains. The resulting tool, named ARTEMIS (Adams-based Rover Terramechanics and Mobility Interaction Simulator), consists of the dynamic model, a library of terramechanics subroutines, and the high-resolution digital elevation maps of the Mars surface. A 200-element model of the rovers was developed and validated for drop tests before launch, using MSC-Adams dynamic modeling software. Newly modeled terrain-rover interactions include the rut-formation effect of deformable soils, using the classical Bekker-Wong implementation of compaction resistances and bull-dozing effects. The paper presents the details and implementation of the model with two case studies based on actu...

Grouting is a frequently used technique for controlling the water inflow and reinforcement of soil and rock. Even though cement-based grouting materials have been well characterized, ongoing improvements of chemical grouting materials create a need to better understand the characteristics of these materials in order to increase the efficiency of grouting applications. The purpose of this study is to characterize three common chemical grouting materials by exploring their mechanical performance under varying initial soil conditions. Performance decision criteria consist of the Unconfined Compressive Strength (UCS) and slake durability test results, observation of penetration ability, and comparison of the findings. The three chemicals used were acrylate, colloidal silica, and polyurethane. Test specimens were prepared with two different sand gradations and two different initial moisture contents, which were compacted to the same constant density. Cylindrical test specimens were injected using a constant and predetermined injection pressure. Injected specimens were moist-, air-and wet-cured for 28 days. Thereafter, the specimens were tested and the stress-strain relationships were developed. Slake durability tests were conducted to characterize the durability of chemically grouted sands subjected to wetting-drying cycles. The results of this study showed that initial grain size and fine content of the soil influenced the resultant strength for acrylate and colloidal silica grouting materials. On the other hand, initial moisture content of soil was solely effective on UCS of acrylate grouted sand. This study found that the effect of wetting-drying cycles on durability was minimum for the polyurethane grouted sands. It may be concluded that use of polyurethane in medium sands and use of acrylate in fine sands can be more effective than the use of acrylate, and colloidal silica for medium sands and the use of polyurethane, and colloidal silica for fine sands. There are numerous people that have helped me to complete this research. I would especially like to thank my advisors, Dr. Norbert Maerz and Dr. John Myers for helping me to advance in this experimental study and providing me the opportunity to benefit from both laboratories of the Rock Mechanics and Explosives Research Center and Civil, Architectural, and Environment Engineering Departments. Also, I am grateful to my thesis committee member Dr. Kyle Perry for all the help during graduate studies. Financial support was provided by Dr. Norbert Maerz for supplying of the testing equipment. Two companies provided chemical grouting materials. I am grateful to Seal-Boss Concrete Solutions and GCP Applied Technologies for supplying the materials. I would like to thank Jim Spiegel and Jason Tolby of SealBoss Concrete Solutions for their assistance. Also, I sincerely acknowledge to Vicki Crosby and Heather O'Hara of GCP Applied Technologies for providing the materials of De Neef. My sincere thanks to Jay Schafler and Jeff Heniff of Rock Mechanics and Research Center for all the help and for the technical assistance during laboratory studies. Also, I would like to thank Steven Michael Lusher for providing material and testing equipment used to conduct the laboratory tests. My colleagues and friends in the Geological Engineering, Geophysical Engineering and Civil Engineering Departments helped me to overcome many difficulties. Thanks to Ali

This themed issue of Environmental Geotechnics brings together seven research articles that investigate the efficacy of different bio-inspired ground improvement solutions across diverse geoengineering applications. The main focus of the themed issue is on biopolymer-based admixtures, which are the subject of four of these articles, plus two investigating MICP, and one exploring the application of lignocellulose-degrading enzymes.

This paper explores the effects of using either stress controlled or strain controlled loading procedure on interpreted values of the pressuremeter modulus (Ep) and the limit pressure (Pl). Pressuremeter tests were performed on different sites using these two loading procedures. A review of litterature is made, test results are presented, and a number of conclusions are given. RÉSUMÉ Cette communication présente une évaluation des effets de la méthode de chargement (par paliers de pression ou de déformation contrôlée) sur le module pressiométrique (Ep) et la pression limite (Pl). Des essais comparatifs ont été réalisés sur différents types de sols. Les résultats de ces essais de même qu’une revue de la littérature sont présentés, après quoi des conclusions sont tirées.

Currently, various methods are used to apply fertilizer under the plow. At the same time, mineral fertilizers are applied to the soil surface after harvesting in our republic with Amazone ZA M-1500 brand disc centrifugal fertilizer spreaders. Immediately after sowing, the plowing operation is carried out with an SP-12 brand fourbody plough so that the applied fertilizers fall under the soil. This is how the operation is performed. The tractor is used twice to carry out this technological operation, which is economically inefficient and inconvenient on slopes. Thus, the centrifugal fertilizer spreader works unevenly. To eliminate this problem, a combined plough was developed in our laboratory. In order to calculate the economic efficiency of the combined plough, the economic indicators of the SP-12 brand four-body plough and the Amazone ZA M-1500 brand fertilizer spreader were compared, and an economic efficiency of 1586.79 AzN (933.41,dollars $) was obtained. The article provides economic tables. The smooth and even distribution of mineral fertilizers in the field with the application of a combined plough increases the yield in grain growing from 26 cent/ha to 32 cent/ha minimally. If we calculate the cost of wheat at about 0.35 AzN (0.21 dollars,$) (per kg, then with 600 kg per hectare, it allows to obtain an economic yield of 210 AzN/ ha (123.53 dollars/ha), and an economic yield of 68040 AZN (40,023.53 dollars $) from 324 ha during the season.

In this study, the tensile and dynamic-mechanical properties of composites made by poly-lactic acid polymer (PLA) and high density polyethylene (HDPE) as matrix and sawdust to reinforcement 30 % weight were investigated. Maleic anhydride bonded with polyethylene (MAPE) was used to increase coupling agent by 3%. The use of sawdust increased the stiffness of composites while the use of this material reduced the tensile strength of composites. The highest tensile properties (elastic modulus and tensile strength) were related to poly lactic acid /polyethylene / sawdust / coupling agent composites. The addition of natural fibers to both matrices (PLA and MAPE) increased the composite storage modulus compared to pure polymers, while the modulus of storage in pure polyethylene and its composite was higher. Simultaneous use of two polymers with an equal ratio (33.5% by weight) and composite sawdust have shown the stiffness between the composites made with single polymers. The use of natural...

On the basis of geological and geomorphological surveys, landslide phenomena are analysed on a slope along a stretch of the Adriatic coast, near Petacciato (Molise, Italy). Locally, a blue clay sequence of Pleistocene outcrops, stratified with silty-sandy layers; bedding dips 3 -8jNE and the slope has a similar attitude. This sequence evolves upwards to sands and conglomerates, with thickness of up to 40 m, on which the built-up area is located. Several episodes of landslide reactivation occurred in the past century, involving the zone between the built-up area and the sea, along a coastal slope of over 2000 m long and 200 m high. Important roads and railway lines have been heavily damaged as well as the town itself. The typology of the movement is a rotational -translational slide; the displacement reaches tens of centimetres at each reactivation episode along the entire coastal slope, extending well beyond the shore line. Detailed studies already exists, but different mechanism failures have been proposed to explain the landslide phenomena. In this study, a new failure mechanism is proposed, (sudden spreading of Terzaghi, K., Peck, R.B., 1948. Soil Mechanics in Engineering Practice. Wiley and Sons New York) and analytical approaches have been adopted to evaluate the slope stability, based on the geotechnical and monitoring data and the geometrical and geological features of the slope.

Several theoretical expressions of the at rest earth pressure coefficient for normally consolidated soils ( 0( NC ) k ) are available in the literature. Some of them have been derived using Critical State Soil Mechanics constitutive models. However, these models usually over-predict the 0( NC ) k values. The possibility to improve, in principle, the 0( NC ) k prediction simply changing the plastic potential surface shape of the Modified Cam-Clay model, i.e. adopting a non-associated flow rule, is described in the paper.

Managing tailings facilities often includes stability and deformation analyses from both short- and longterm perspectives. Behind these analyses, geotechnical theories are applied on the studied material. Design for closure is often considered to cover a period of 1,000 years, during which time the closed tailings facility should be stable, both physically and environmentally. Since the use of tailings facilities only covers about 100 years back in time, there are still no data on how tailings behave in the long term. In Sweden, correlations to natural formations have been used to predict the long-term stability of tailings dams. Natural formations that have been stable since the latest ice age (approximately 10,000 years ago) are considered good examples of long-term stability. These are mainly formed by glacial till, a natural material that has been subject to erosion, transportation, and sedimentation processes. Tailings material, however, is artificially created and differs in s...

Pile foundations are relatively vulnerable to lateral loads. During liquefactioninduced lateral spreading, this vulnerability is particularly conspicuous due to a loss of strength and stiffness in the liquefied soil. A nonlinear effective stress analysis incorporating an elastoplastic constitutive model based on Finite Difference Method (FLAC 2D program) was used to numerically simulate shake table experiment on piles in laterally spreading soils. The soil-pile interaction has been properly considered by using interface elements. The main objective of this paper is to assess the accuracy of a 2D numerical simulation of physical models in predicting the dynamic response of pile foundations and to identify the capability of 2D numerical simulation for 3D effects such as shadow and neighboring effects in pile groups without a pile cap. Results are presented and discussed, in which the obtained response from the simulation is compared to that measured in the test. For the single pile, a fairly good agreement was observed between computed and measured results. It was also found that the shadow and neighboring effects reduced lateral load on the piles by few percent of difference compared with experimental results.

Le comportement d'un remblai sur sol liquéfiable soumis à des sollicitations sismiques sera étudié sur modèle réduit centrifugé. Une étude numérique, faite en amont, contribue à la conception du modèle réduit et à l'évaluation des effets de bord de deux conteneurs, l'un rigide et l'autre laminaire.

We present a three-dimensional discrete-element approach for numerical investigation of wet granular media. This approach relies on basic laws of contact and Coulomb friction enriched by a capillary force law between particles. We show that the latter can be expressed as a simple explicit function of the gap and volume of the liquid bridge connecting a pair of spherical particles. The length scales involved in this expression are analyzed by comparing with direct integration of the Laplace-Young equation. We illustrate and validate this approach by application to direct shear and simple compression loadings. The shear and compression strengths obtained from simulations reproduce well the experimental measurements under similar material and boundary conditions. Our findings show clearly that the number density of liquid bonds in the bulk is a decisive parameter for the overall cohesion of wet granular materials. A homogeneous distribution of the liquid within the bridge debonding distance, even at low volume contents, leads to highest cohesion. The latter is independent of the liquid content as far as the liquid remains in the pendular state and the number density of liquid bonds remains constant.

Geosynthetic-reinforced embankments are essential for stabilizing structures on weak soils or sinkhole-prone areas by redistributing loads through soil arching and membrane effects. This study investigates the effectiveness of these load transfer mechanisms using a combined approach of multi-trapdoor tests and Finite Element Method (FEM) simulations. The objective is to analyze the impact of embankment height, base geometry, and geosynthetic stiffness on load distribution and settlement reduction in reinforced embankments. The principal findings indicate that increasing embankment height amplifies the soil arching effect, significantly reducing stress concentration in weak areas and minimizing differential settlements. Additionally, geosynthetics with higher stiffness were found to enhance the membrane effect, leading to more uniform load distribution and reduced deflection. The FEM results aligned closely with experimental data, with difference under 10%, pointing the accuracy of the model. Notably, the combination of increased geosynthetic stiffness and optimized embankment configuration results in nearoptimal load transfer efficiency. These insights suggest that optimal combinations of embankment height, geosynthetic stiffness, and base geometry can improve stability, especially in geotechnical applications on weak foundations. This research provides a foundation for future studies exploring 3D modeling and larger-scale testing to refine these findings further and contribute to effective embankment design in complex soil conditions.

Acid sulfate soils (ASS) are distributed worldwide on coastal floodplains, presenting a great challenge to coastal development and urbanisation. Upon oxidation, these soils become stratified with visibly distinguishable soil strata that are progressively less oxidised with depth. In this study, the geotechnical properties, quantified by hydraulic conductivity and consolidation coefficient, of an ASS profile from the Tweed River floodplain, north-eastern New South Wales, Australia, were investigated at a laboratory scale and compared with results obtained from the field. Measurements were conducted with a Rowe cell (or hydraulic consolidometer) by controlled compressive and pore water pressures. The results indicated that hydraulic conductivity and consolidation coefficient values gradually decreased with increasing consolidation pressure or decreasing void ratio, but were significantly higher for the more oxidised ASS horizons. These results suggest that controlled soil consolidatio...

The classical theory of one-dimensional consolidation, formulated by Terzaghi, provides a fundamental framework for understanding time-dependent settlement in saturated finegrained soils. While analytical solutions exist for idealized scenarios, particularly those assuming a uniform initial excess pore pressure distribution (u e (z, 0) = u 0), practical situations often involve initial states where pore pressure varies with depth, u e (z, 0) = f (z). This paper presents a comprehensive formulation using the Finite Element Method (FEM) to solve Terzaghi's 1D consolidation equation specifically for such spatially variable initial conditions. We detail the standard weak form derivation, spatial discretization with linear elements, and temporal integration using the implicit Backward Euler scheme. The primary focus is on the rigorous implementation of the arbitrary initial condition function f (z) to define the initial nodal state vector U 0 e , including the consistent application of boundary conditions at time t = 0. The handling of both Dirichlet (drained, u e = 0) and Neumann (impermeable, ∂u e /∂z = 0) boundary conditions during the transient simulation is also elaborated. The methodology provides a robust and flexible numerical tool for analyzing 1D consolidation problems starting from non-uniform initial pore pressure states across various drainage conditions.

This paper presents the idea on determination of liquid limit and plastic limit with soil electrical resistivity in geotechnical investigations. Depending on the moisture contents, the soil behavior is revealed as solid, semisolid, plastic and liquid states in geotechnical engineering and other division of civil engineering. Determination of liquid limit and plastic limit of soil in conventional laboratory test is very tedious, slower and costly for the laboratory testing example as fall cone testing with a lot of collected soil sample. In this work, a method of soil liquid limit and plastic limit determination with electrical resistivity is revealed to define the state of soil as well as the relationship of soil particle distribution in the soil site investigations of geotechnical engineering. In addition, soil resistivity measurements with moisture contents and conventional laboratory test as fall cone test are performed whereas experimental results in laboratory and results from the available literature review are considered. A good correlation of soil electrical resistivity and moisture contents is demonstrated in results to determine the liquid limit, LL and plastic limit, PL in soil behavior. The research is most significant to obtain faster, cost-effective and consistent performance in soil liquid limit and plastic limit determination through electrical signal for a wide range of applications in geotechnical engineering.

Ключови думи: подпорна стена, укрепителна стена, ЕК7, второ поколение РЕЗЮМЕ Второто поколение внася промени в различни аспекти на геотехническото проектиране. Указанията за проектирането на укрепителни конструкции вече се намират в Глава 7 на новата част 3 от второ поколение на Еврокод 7. Тази статия представя новите аспекти в проектирането на укрепителни съоръжения и сравнение с действащите в България НППС и Еврокод 7-първо поколение.

Това изследване представя принципните разлики между НППС [1] и ЕК7 [2] при проектиране на лека подпорна стена. Изследвани са различията в нормативната постановка. Направено е сравнение на числен пример, като са показани разликите в коефициентите на сигурност при вариация на геометрични размери на стената, както и на параметрите на почвата, използвана за обратен насип. Проблемът е изследван само за статичен товар. За динамично натоварване е направено изследване в [3].

Soils are generally of two types-expansive soils such as Black Cotton Soil (BCS) and non expansive soils like Red Earth Soil (RES). This paper describes the strength and consolidation behavior of Red Earth Soil treated with lime. It is found from compaction and unconfined compressive strength test that Red Earth Soil with 3% lime is considered as optimum. On the basis of unconfined strength test it was found that addition of optimum lime to RES increases strength by 5 times when compared with soil alone at 30 days curing. Addition of 3% lime to RES reduces the final voids ratio by 4% and coefficient of compressibility by 39% when compared with soil alone.

En muchos países hay diversas formas de planear y analizar estructuras históricas,
previo a la intervención de estas, pero hay otros muchos lugares que cuando intervienen las construcciones antiguas tienen un enfoque más emocional en la práctica, en vez de tener un enfoque profesional que una actividad con soporte científico. De ahí que es común que en la práctica profesional al tratarse de conservación y restauración de estructuras antiguas se usen herramientas para el modelado estructural computacional contemporáneas, en sí, muchas de estas herramientas son limitadas por la naturaleza matemática del método de elementos finitos continuos (FEM). Sin embargo, estos instrumentos numéricos son útiles para evaluar el sistema estructural y posibles áreas con un deterioro o daño estructural. Para comparar la efectividad de este tipo de análisis, la simulación se basa en 2 herramientas numéricas que son comúnmente utilizadas en la práctica profesional (elementos shell y solidos) son llevados acabado, con la factibilidad de generar modelos representativos del objetivo físico que se está revisando. Vale mencionar que hay otras herramientas físicas con una gran eficiencia en términos de resultados locales que pueden ser obtenidos con representaciones de mampostería irregular, este trabajo se enfoca especialmente en las herramientas comúnmente usadas en México, y en la práctica profesional contemporánea. También, se necesario revisar el equilibrio en la estructura, una comparación entre resultado con métodos gráficos y el método de elementos finitos. En conclusión, este trabajo sirve de base para realizar prácticas similares y otras adaptaciones en la práctica profesional en por lómenos previo al análisis en el estado real de la intervención, asimismo la premisa que describe este documento es recomendar la comparación entre las propiedades que tienen los análogos y análisis virtuales compatibles con los mismos. Por último, este documento tiene como propósito demostrar en un nivel internacional la importancia de las diferencias entre los métodos existentes en el análisis estructural y los beneficios que tienen para prevenir daños en el objeto patrimonial.

Expansive soil shows large volume change behavior when subjected to different moisture condition. Uplift of light weight structures occurs due to the swelling of soil. To increase the uplift resistance granular pile, anchors are used with and without reinforcement. Model studies are performed on granular piles anchors to check the pullout resistance. Study include testing of granular pile anchors with and without reinforcement in unsaturated and saturated condition. Black cotton soil was collected from Palakkad district. The initial test on soil was done and it is found that the soil is silty clay. A model test tank of 50cmx50cmx60cm dimensions are made. Pullout test is done to determine the pullout capacity of GPA, pullout test is done with different l/d ratio in unsaturated condition with and without reinforcement. From the result obtained it is seen that, when the l/d ratio increases the pullout resistance also increases and the maximum result obtained is 99.7N for l/d ratio equa...

Rainfall-induced landslides pose a significant risk to communities and infrastructures. To improve the prediction of such events, it is imperative to adequately investigate the rainfall-dependent dynamics (leading to fluidization) and any associated internal sliding along shear planes within clayey slopes. Therefore, the present study adopted ambient noise analysis based on the Horizontal to Vertical Spectral Ratio (HVSR) method, to measure the seasonal variation of Rayleigh wave ellipticity as an indicator for the internal deformation and transition in the material state. The methodology was applied to an existing landslide, where variations in soil stiffness and internal sliding were expected to occur in response to rainfall. To improve the interpretation of the HVSR results (and hence the prediction of landslide’ reactivation by rainfall), HVSR measurements were also conducted on a field-scale pile load test. The pile test allowed a comparison of the seismic data generated by the...

La consolidación es un proceso fundamental en la ingeniería geotécnica, que describe la disipación del exceso de presión de poros en suelos saturados bajo carga. La teoría de consolidación unidimensional de Terzaghi proporciona la ecuación diferencial parcial que gobierna este proceso. Aunque existen soluciones analíticas, los métodos numéricos, como el método de diferencias finitas (MDF), son herramientas poderosas para obtener soluciones aproximadas, especialmente en casos complejos. Este documento describe la derivación de la ecuación de consolidación, detalla la aplicación de los esquemas de diferencias finitas explícito e implícito para su resolución numérica, y explica cómo incorporar diferentes condiciones de contorno (drenantes e impermeables) en la formulación numérica. Se discuten las ventajas, desventajas y criterios de estabilidad de cada esquema.

En este trabajo se plantea el uso del método de los elementos finitos para el estudio de las transmisiones laterales a través del índice de reducción de vibraciones, para el caso de soluciones constructivas con suelos flotantes. Por una parte, la inserción de láminas elásticas en nuevas soluciones constructivas es en la actualidad una práctica muy común. Por otra parte, los procedimientos de ensayo para el estudio acústico de este conjunto (forjado con lámina elástica) son muy laboriosos y las ecuaciones empíricas existentes no satisfacen la realidad en muchos de los casos. Es por este motivo que se plantea el estudio mediante los elementos finitos, lo que nos permitirá dar solución numérica a un gran conjunto de diferentes soluciones constructivas y poder así mejorar las predicciones numéricas para el aislamiento acústico.