Soil Mechanics

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.

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.

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 toposequence 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.

A study was performed to evaluate the soil improvement and stabilization potential of several tropical Hawaiian soils. These improvement techniques included stabilization with locally generated high-quality fly ash, and locally available hydrated lime admixtures. Use of these admixtures has shown tremendous potential as an economical method to upgrade the geotechnical properties of several «poor to marginal» types of tropical Hawaiian soils. The study shows such improvements as increase of unconfined compressive strengths; increases in California bearing ratio (CBR) of more than 10-fold; reduction in plasticity; reduction in swell to less than 10 percent of the unstabilized values; greatly increased workability; and changes in moisture-density relationships resulting in lower maximum dry densities, higher optimum water content, and less variation of dry density from the maximum over a much wider range of water contents

Este artı́culo presenta una formulación enfocada para la solución numérica de la ecuación de consolidación unidimensional en suelos estratificados, especı́ficamente considerando el caso de dos capas arcillosas distintas. Se emplea el método de diferencias finitas para discretizar las ecuaciones
diferenciales parciales y se discuten las condiciones de contorno en los extremos del dominio y en la interfaz entre las capas. Se proporciona un esquema completo para todas las combinaciones posibles de condiciones de contorno, incluyendo casos de drenaje libre e impermeabilidad. El objetivo es ofrecer una guı́a para la implementación numérica de este problema geotécnico fundamental.

Many structures that have been constructed on gypsiferous soils have big problems, especially in drying-wetting sequence, contrast of construction on non-gypsum-soils due to the collapsibility of gypsum. These soils are formed by the evaporation of saline groundwater when the water table is near the ground surface. Gypsiferous soils are widespread in the Middle East especially in regions peripheral to the Red sea and Arabian Gulf. They cover large areas of Iraq which may be extended to 20% of the total Iraq's area. The present work condenses on the effect of soaking and leaching progresses on the soil stability in the saturated and unsaturated conditions.

Pile foundations now make up a greater percentage of foundations for new construction. That is why, an accurate calculation of pile resistance and the knowledge of its reliability has a great economic importance. A more rigorous approach has become necessary since the introduction of Eurocodes. The pile resistances are more often calculated based on CPT results. This paper suggests a new method based on comparison of several approaches and recent design experience. The method takes into account soil type and piling technology. It was verified by 63 pile load tests and its reliability was evaluated as well. This paper contains the first part of the author's PhD thesis which was written at University of Miskolc under the supervision of Professor Imre Szabó. Pile foundations have now become a very common alternative for new construction. In the last 15 years, the continuous flight auger (CFA) method has been the dominant method for pile installation. Alternatively, bored piles made with slurry or casing are used only for diameters in the range of 120÷150 cm. Traditional precast concrete driven piles are declining and the modern types of these piles (cylindrical, conical, prestressed and jointed) have not been readily adapted by contractors. Driven cast-in-place piles are also rarely used and the Franki-method; once very popular in Hungary, has almost disappeared. On the other hand, a new displacement pile type, the screwed pile (Screwpile, Omega, Atlas, TSD, CMC etc.) has gained acceptance and is expected to be more common than the CFA-pile within 10 years. It can be installed as fast as the CFA-pile, it does not disturb the environment, nor does it produce soil to transfer and sometimes to handle as a hazardous material. Its specific bearing capacity can be higher due to the compactive effects of soil displacement. Piling technology has an important influence on the pile resistance. So, the appearance of new types and changes in the proportion of different types' utilization cause new design challenges for the geotechnical engineer. The increase in piling volume enhances the claim for a more economical design. In this situation, engineers dealing with these questions on a scientific level should find answers for these challenges. They should develop methods which can allow for the design of different pile types in a unified, fast, reliable, and economical way. Beginning in 2011, structures and the piles that support them must be designed to meet the requirements of Eurocode . For pile design, the engineer should verify that the GEO ultimate limit state will not occur (Eurocode, 2004). This means there should be no strength failure in the soil. For the determination of the compressive resistance failure of a single pile, EC 7 accepts three methods: 1. static load tests on similar piles; 2. dynamic load tests verified by static load results 3. empirical or analytical calculation methods validated by static load tests. The calculation method based on ground test results

Pile foundations now make up a greater percentage of foundations for new construction. That is why, an accurate calculation of pile resistance and the knowledge of its reliability has a great economic importance. A more rigorous approach has become necessary since the introduction of Eurocodes. The pile resistances are more often calculated based on CPT results. This paper suggests a new method based on comparison of several approaches and recent design experience. The method takes into account soil type and piling technology. It was verified by 63 pile load tests and its reliability was evaluated as well. This paper contains the first part of the author’s PhD thesis which was written at University of Miskolc under the supervision of Professor Imre Szabo. RESEARCH TOPIC

This paper presents the theoretical background of a phenomenological biphasic material approach at large strains based on the theory of porous media as well as its numerical realization within the context of an adaptive mixed finite element formulation. The study is aimed at the simulation of coupled multiphysics problems with special focus on biomechanics. As the materials of interest can be considered as a mixture of two immiscible components (solid and fluid phases), they can be modeled as saturated porous media. For the numerical treatment of according problems within a finite element approach, weak formulations of the balance equations of momentum and volume of the mixture are developed. Within this context, a generalized Lagrangean approach is preferred assuming the initial configuration of the solid phase as reference configuration of the mixture. The transient problem results in weak formulations with respect to the displacement and pore pressure fields as well as their time...

Pada proyek pembangunan Tol Surabaya-Mojokerto Seksi IV terdapat kali sidoduwe yang menjadi pemisah main road tol Surabaya- mojokerto, sehingga diperlukan perencanaan jembatan. Dalam hal ini akan direncanakan timbunan di dekat jembatan (oprit) yang menjadi penghubung main road dengan kepala jembatan, perencanaan dimulai dengan merencanakan bearnya pemampatan yang terjadi pada STA 37+575-37+325 dengan tinggi timbunan final (H final)sisi tertinggi yang direncanakan berturut –turut sebesar 7,746 m, 6,787 m, 6,423 m, 6,90 m, 5,959 m, 5,492 m, 4,922 m, 4,088 m, 2,792 m, 2,427 m, 2,304 m. Tinggi timbunan awal (H initial) dan H akhir (H final) diman ada lama merencanakanya menggunakan persamaan yang diperoleh dari grafik perhitungan H awal (H initial) dan H akhir(H final) dengan beban pemisalan sebesar 3 t/m2, 5 t/m2, 7 t/m2, 9 t/m2, 11 t/m2, 13 t/m2, 15 t/m2, 17 t/m2.Kemudian dilanjutkan dengan menganalisis besarnya waktu pemampatan tanpa PVD, didapat t = 64,72 tahun dalam hal ini waktu y...

Zeta potential is known as the electrical potential at the shear plane and is one of the important electroosmotic properties of clay minerals. For many applications, the sign and the magnitude of the zeta potential is necessary to be known. For clay soils, it is usually negative. In present study, zeta potential of kaolinite clay immersed in various electrolytes namely; CaCl 2 , Al 2 (SO 4 ) 3 , H 3 PO 4, Na 2 Sio 3 , and Na 2 Co 3 at different electrolyte concentration is investigated. As a result, the pH strongly altered the zeta potential of kaolinite. Also, zeta potential and specific conductivity have ranged from -86 to +204mV and 1450 to 15900µs/cm, respectively, at pH 2 to 9.3. In addition, pure kaolinite yields in an isoelectric point (IEP) at pH ~ 3.15.Although, there was no IEP for particles suspended in CaCl 2 solution, a shift in IEP towards alkaline part observed when kaolinite particles immersed in Al 2 (SO 4 ) 3 as well as H 3 PO 4 solution.

Análisis del proceso constructivo y variabilidad de parámetros geotécnicos en la capacidad de carga de micropilotes usando elementos finitos aleatorios. Obras y Proyectos 11, 61-70 a la presente investigación con el proyecto 00004711 -Estudio experimental de la licuación por flujo. Los autores agradecen al MOX de la Universidad de Los Andes -Bogotá -por el soporte computacional para la realización del presente proyecto.

Critical and residual states are key soil conditions relevant to slope stability. Evaluating the available shear strength in relation to these conditions is crucial for reliable stability analyses. However, limited availability of direct measurements in the usual engineering practice makes such evaluation seldomly straightforward. The issue is sometimes alleviated by utilising empirical correlations with soil index properties, more easily determinable, yet much care is needed in applying generic correlations to specific materials, as the related uncertainties might override their predictive capability. By analysing soil samples from the Dobkovičky landslide in Czech Republic, we discuss the extent to which some established correlations can be misleading, but also that relationships calibrated on site-specific data are not necessarily performing better. We then demonstrate that empirical models may fail to capture correlations if the sample set is rather homogeneous and noise from reasonable experimental uncertainties is introduced. Finally, we provide some guidelines on the use of different soil strength parameters, laboratory tests, and empirical relationships for slope stability analyses in engineering practice.

Parallel edge-based data structures are used to improve computational efficiency of Inexact Newton methods for solving finite element nonlinear solid mechanics problems on unstructured meshes composed by tetrahedra or hexaedra. We found that for tetrahedral meshes, the use of edgebased data structures reduce memory requirements to hold the stiffness matrix by a factor of 7, and the number of floating point operations to compute the matrix-vector product needed in the iterative driver of the Inexact Newton method by a factor of 5. For hexahedral meshes the reduction factors are respectively 2 and 3.

During the preparation of this work were performed numerical modeling based on an adequate conceptual framework, contemplating interpret and predict the response of this hydro geological material, to effects of alterations in the environment can have on the evolution over time of the water pressure in the pores, the total stress and displacement. The modeling of hydrological and mechanical aspects were used for this work, taking as reference the conditions under which they were made the extension work of the laboratory. iv iv INDICE AGRADECIMIENTOS .

Direct-action and indirect-action vibrators for compaction of silage in container stores were built for experimental trials. Experimental results indicated that during vibrating compaction the grass layer was compacted intensely for 5-10 min. Therefore, vibrators of this type are suggested for compacting grass layers with thicknesses of 0.5-0.6 m. The determination of comparative pressure as a function of vibration frequency showed that the most effective frequency was 43.96 Hz during the direct-action vibrator compaction of grass. This relationship was determined experimentally by measuring the pressure caused by the vibrator and the effective power while compacting the grass mass in a container. The pressure increase coefficient varied over a wide range of 1.5-6.8. It was established that a centrifugal indirect-action vibrator works well to compact chopped maize (a bulk density of up to 730 kg m-3 was achieved) and works to some extent for mixtures of Caucasian goat’s rue (Galegao...

Cracks were mostly studied in: high clayed soil (Vertisol). This study used agricultural soil found in Gembloux-Belgium (Silt-loam). Aims: Insight on crack dynamics during dryings and re-drying of conventional and reduced tillage soil. Water evaporation : Disturbed soil  Reduced-tillage > Conventional tillage -Cracks increased the surface of evaporation(Figure ). -Cracks exposed water to atmosphere (without passing the soil matrix). -The soil temperature was stabilised at 25°C for all experiments. -Cracks in disturbed soil > reduced-tillage > conventional tillage. Due to no soil cohesion, soil OC, soil aggregation, biological activities, and soil porosity. -The opening increased the soil desiccation rate in disturbed soil  reducedtillage > conventional tillage. -Re-drying process increased the size of the previous cracks. X-ray scan is necessary to observe the presence of pre-(micro) cracks in soil.

Subgrades of Al-Kut city soils are mostly silty clay. Due to a lack of cohesiveness, these soils are relatively weak. A list of problems might occur when the soil is medium stiff clay. Settlement and structural instability are caused by soft soil. Medium saturated fine grain soils have a low undrained shear strength and high compressibility. This type of soil can induce cracking and collapse in geotechnical projects. The purpose of this study is to see how traditional soil stabilizers (cement and lime) affect the stability and bearing capacity of the soil. The soil test was taken from the ground level (shallow depths). To investigate the influence of these two additives on soil bonding and waterproofing, 8% of each weight of dry soil was applied separately. Then, using a proportion of 4 % of dry soil weight each, cement and lime were combined, and a comparison was conducted. Physical, engineering, and mineral examinations were performed on prepared soil specimens before and after the addition of conventional stabilizers. Atterberg limits, compaction test, and consolidation test were among the tests performed. The results showed that adding cement to the soil improved soil characteristics and γd,max = 1.5 gm/cm 3 more effectively than using the same percentage of lime (γd,max.lime = 1.4 gm/cm 3). The most successful method was to use 4% cement and 4% lime. Observing the results, the value of γd,max increased to 1.64 gm/cm 3. When compared to the expense of just adding cement or lime, this has the potential to provide more significant consolidation outcomes at a more acceptable and fair cost.

Geotechnical engineering design necessitates a study of soil parameters for calculation purposes. As a complement to the conventional method, a resistivity survey can give preliminary results in a short amount of time. This study uses a statistical analysis program to show a correlation and regression for predicting soil parameters based on the resistivity value. Sixty-six data points for each soil parameter and resistivity were used for statistical analysis from six profiles of the study area as a part of the investigation. The soils are sampled by drilling the borehole up to a depth of 3 meters. The Wenner array was applied to conduct a resistivity survey. The collected data were utilized to establish a correlation between resistivity (ρ) and soil parameters such as moisture content ( w ), clay content (clay), plasticity index ( P I ), friction angle (ϕ), bulk density (γ), and porosity (n). The generated statistic model was improved through several iterations for each correlation....

The simulation of the hydro-mechanical behavior of unsaturated soils is becoming a subject of major importance in soil mechanics. However, unlike the laws governing the behavior of saturated soils, those used to describe the behavior of unsaturated soils still lack of simplicity for common engineering practice. This is why it is important to reconcile saturated and unsaturated soil mechanics and establish a unified theory. In this paper, we use the same strength equation of saturated soils in unsaturated materials and verify that a single failure surface is obtained for any value of suction in wetting and drying paths.

Both draft force and soil breaking up of clods of soil are in function of the kind of tool, geometry and operational conditions. In order to analyze the effect of the conditions of operation (density of mesh) and the geometry (attack angle of wedge) in the tractional force of a vibratory scarifier of curved arm tilling a Rhodic Ferralsol soil , the soil was considered as homogeneous material. The model extended linear Drucker Prager's elastoplastic of constitutive relation was used for this modelation by finite elements and soil-tillage tool interaction was modeled with surface to surface contact and the software Solid Works and its complement simulation were used. When increasing the angle of attack of the wedge, the grade increases in displacement of the particles of soil, both, in the direction of advance of the tool and in vertical sense, and the values of the tensions of contact in the nodes grow, mainly located in the tip of the tillage tool of cultivation and the plane of...

This communication article presents a discussion of various identified shortcomings in the original research paper by Thapa et al. (the Authors) that was recently published in Transp. Infrastruct. Geotech. 11(6), 3941-3968, 2024. The Authors investigated the application of waste shredded rubber pieces (SRPs) for improving the performance of shallow foundations bearing on a problematic collapsible soil obtained from the Western Uttar Pradesh region of India. They performed laboratory experiments, including Atterberg (consistency) limits, compaction, unconfined compressive strength and undrained direct-shear tests, on the unamended soil (i.e., 0% SRP content) and five soil-SRP blends prepared with gravimetric SRP contents ranging from 1% to 5%. Moreover, the Authors employed finite-element method (FEM) modeling to assess the effects of SRP content on the ultimate bearing capacity (B) and settlement (S) response of an infinite strip footing bearing on the investigated compacted soil-SRP blends. Using the results obtained from the six FEM simulations, the Authors then produced multiple linear regression (MLR) models for predicting the FEM-generated B and S values of the compacted soil amended with 0-5% SRP additive. In this communication article, the Discussers raise several shortcomings of the Authors' research, including (i) the presented Atterberg limits results are fundamentally compromised by the inclusion of the coarse SRP additive in the test material, and (ii) the validity and applicability of their proposed MLR models for predicting the B and S responses of shallow footings bearing on the SRP-amended soil.

This paper presents a novel experimental investigation for improving the bearing pressure resistance of medium-dense sand deposits. Model footing tests were performed on similarly prepared sand beds to examine the effects of incorporating one, two and three separate geogrid-reinforced thin densified gravel layers at various depths within the beds. Additional load tests investigated incorporating only geogrid-reinforcement layers or densified gravel layers of different thicknesses placed separately within the sand beds for the purposes of establishing their resistance contributions. Furthermore, a dimensional analysis relating the model test results to the large-scale conditions is presented. Compared to the unreinforced medium-dense sand bed, superior bearing-pressure resistances (and reduced footing settlements) were achieved for including the geogridreinforced gravel layers. For example, at a settlement ratio of 2% (s/D = 2%), the inclusion of one, two, and three geogridreinforced thin densified SwG layers improved performance by 68%, 110%, and 124%, respectively, compared to the unreinforced sand bed. Increasing the number of these layers (from one to three) produced improved geomechanical performance, albeit more layers produced diminishing returns. The basic mechanisms responsible for the improvements in bearing pressure resistance are elucidated. This study demonstrates that when suitable engineering fill is unavailable, the concept of incorporating geogrid reinforced thin densified granular layers in the backfill could be of practical application for constructing reinforced footings, reinforced soil walls, etc.

The present work presents a study on an emergency containment work carried out on one of the main avenues of the capital of Minas Gerais in the year 2018. This structure comprises a curtain anchored by rods installed on a containment of the same nature that was instated as a function of corrosion in the head of the rods due to saturation of the slope. The stability of the problem was analyzed by means of the rigorous equilibrium-limit method (Morgenstern-Price), with the help of GeoStudio 2019 software, SLOPE/W module. Through modeling using finite elements in the Sigma module of GeoStudio, A 2D strain study was carried out for the following "In Situ" scenarios (before reinforcement rods and after the application of the new reinforcement lines). Additionally, the Elastoplastic model was considered representative of the Geotechnical massif. In general, the study returned a significant increase in the safety factor of the slope conferred by the anchored wall and acceptable h...

The worldwide increase in production of water treatment sludge together with the overwhelming disposal cost has fuelled research into the development of economic re-use alternatives. This study investigated the shear behaviour of unmodified and modified clay to determine the potential of using lime-iron sludge as a soil modifier. The effects of lime-iron sludge concentration, moisture content and vertical normal stresses were examined. The optimum dose of lime-iron sludge was found to be 3% with an accompanying optimum moisture content of 20%. An improvement of 20% increase in shear stress together with a rise in cohesion of 155% was observed. However, the inclusion of lime-iron sludge in soil specimens had no significant effect on the internal friction angle. Experimental results were successfully used to illustrate the positive effect of lime-iron sludge inclusion on the shear behaviour of soil. Additionally, experimental data was successful in correlating shear variables and opti...

Систематизирането на изследванията и знанията за почвите включва основно тяхната номенклатура, диагностика и класификация за различни цели. Почвената им класификация много често е синоним на систематика и обединява останалите научни подходи и направления в почвознанието. Ако генезисът изучава произхода и същността на почвите, а диагностиката ги разпознава и дефинира чрез техните свойства и признаци, то класификацията оценява, подрежда и систематизира почвите на базата на доказани процеси, явления и качества (Теохаров, 2005). Черноземите в България са добре изучени, но въпреки това съществуват "бели петна" в зависимост от техните местни особености и поради липса на съвременна информация за агроекологичните въздействия и промени върху техния статус и плодородие. Пушка-

It is increasingly apparent that faults are typically not discrete planes but zones of deformed rock with a complex internal structure and three-dimensional geometry. In the last decade this has led to renewed interest in the consequences of this complexity for modelling the impact of fault zones on fluid flow and mechanical behaviour of the…

This report describes the research completed under the project titled "Soil-Structure Interaction Parameters For Structured Silts." The main objective of this research was to characterize the drained stress-strain behavior of naturally occurring structured/ cemented silts. The results of this research were also used to develop recommendations for drained hyperbolic stress-strain and Mohr-Coulomb shear strength parameters for use in soil-structure interaction analyses involving structured/cemented silts. This research utilized oedometer and isotropically consolidated-drained triaxial compression tests on structured/cemented and reconstituted specimens to evaluate the importance of the structure/cementation on the stress-strain behavior and anisotropy of silts. Triaxial compression tests were conducted on structured/cemented and reconstituted specimens at the natural degree of saturation and after laboratory saturation to investigate the effect of saturation on the drained stress-strain behavior of silts. In addition, unload/reload triaxial compression tests were conducted to estimate the unload/reload modulus and the effect of unloading/reloading on the degradation of the structure/cementation of silt.

Piled raft foundations have gained significant popularity in recent years due to their ability to enhance bearing capacity, minimize settlement, and mitigate differential deflection. This foundation system efficiently distributes structural loads, with the raft directly transferring part of the load to the soil while the piles contribute through skin friction. Compared to conventional pile foundations, piled raft foundations offer economic advantages by allowing pile termination at higher elevations without penetrating the full depth of weak soil layers. However, they exhibit more settlement than pile foundations but less than raft foundations, making them a balanced alternative in geotechnical engineering. This review paper analyses key parameters influencing the behaviour of piled raft foundations, including raft size and thickness, pile diameter and length, pile configuration, and the stiffness of both raft and piles. The study provides insights into optimizing design parameters for enhanced performance and efficiency. Based on existing research, recommendations are proposed for selecting the most suitable piled raft configurations, ensuring an optimal balance between cost-effectiveness, settlement control, and load distribution.

Penelitian bertujuan untuk mengetahui hubungan antara keterampilan proses sains dan self efficacy mahasiswa Teknik Sipil pada mata kuliah Mekanika Tanah . Jenis penelitian adalah korelasi dengan melakukan observasi dan pemberian angket. Sampel penelitian terdiri dari 53 mahasiswa Jurusan Teknik Sipil. Instrument terdiri dari angket untuk mengukur self efficacy dan lembar observasi untuk mengukur keterampilan proses sains. Data hasil kedua tes dianalisis dengan korelasi pearson product moment. Hasil penelitian menunjukkan adanya korelasi positif antara keterampilan proses sains dan self efficacy mahasiswa.

Expansive clay soils, characterized by their propensity to undergo significant volume changes in response to moisture variations, present considerable challenges in construction engineering. These challenges manifest as structural damage, including fractures, asymmetrical settlements, and erosion. This study investigates the application of sustainable waste materials, specifically a mixture of plastic and glass waste, as an innovative approach to soil stabilization. In the context of Anbar, Iraq, laboratory experiments were conducted to evaluate the efficacy of incorporating plastic and glass waste in various proportions (0%, 4%, 5%, 6%) into clayey soil. The primary focus was to assess changes in geotechnical properties, notably the reduction in swelling potential and alterations in the maximum dry unit weight of the soil. Results indicated that the inclusion of waste materials in the specified proportions significantly mitigated the soil's swelling behavior, with reductions of 2%, 3%, and 5% observed for the respective waste content. Concurrently, enhancements in soil density were recorded, with increases in the maximum dry unit weight by 4%, 5%, and 9% corresponding to the same proportions of waste additives. These findings underscore the potential of using recycled waste materials in soil stabilization, aligning with environmental sustainability goals through the repurposing of waste. Additionally, this approach offers an economically viable alternative to traditional stabilization methods. The utilization of waste materials not only addresses the environmental impact of construction activities but also contributes to the broader goal of waste management and resource conservation.

The design and evaluation of mechanically stabilized earth (MSE) wall structures for riverbank protection, quays, sea walls and other waterfront structures is critically dependent on a design parameter called the interaction coefficient (Ci) for submerged or fully saturated condition. However, the available research works conducted in this field are limited to non-submerged and, at most, partially saturated condition. This limitation does not closely represent actual conditions where waterfront structures are almost often submerged and fully saturated. Hence, the objective of this study was to determine the Ci in a submerged condition, on top of the Ci in a non-submerged condition for different types of geogrid reinforcement for fine-grained soils and coarsegrained soils used for MSE walls. Test results revealed that the Ci decreased as the effective overburden stress increased. The submerged conditions yielded lower Ci compared with non-submerged conditions, and the reduction wassi...

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.

In this research, the philosophy of manufacturing the geogrids in their conventional shape is modified to let the friction between the ribs and soil particles have a noteworthy effect on the final resistance of soil reinforced by geogrids. Inspired by the belts used to link gears, both surfaces of the conventionalBiaxial Geogridwere reformed by adding cubic cogs distributed in a sine wave order on both sides of the ribs. The proposed geogrid shall be denominated "ICB-GGR"as an abbreviation for Isometric Cogged Biaxial Geogrid. In order to study the improvement in the soil-cogged geogridinteraction, prototypes of theconventional Biaxial geogrid and the modified ICB-GGR were manufactured of steel 37with the same dimensions of apertures and ribs. After many unsucccessful trials to manufacture polymeric geogrid prototypes due to some technical difficulties, steel 37 was the most appropriate material to accomplish the researchsince the main target isto investigate theshapeeffect of the proposed ICB-GGR.Pull-out tests were operated according toASTM D 6706-0101with some modifications to suit the laboratory preparations.The geogrid prototypes were used to reinforce uniformly graded sand and were tested under three different values of overburden pressures. The results showed that thepull-out resistance of the proposed ICB-GGR superior the conventional Biaxial Geogrid by about 50%.

Granular  Pile  Anchor  (GPA)  is  one  of  the  innovative  foundation  techniques,  devised  for mitigating heave of footing resulting from the expansive soils. This research attempts to study the heave behavior of (GPA-Foundation System) in expansive soil. Laboratory tests have been conducted on an experimental model in addition to a series of numerical modeling and analysis using the finite element package PLAXIS software. The effects of different parameters, such as (GPA) length (L) and diameter (D), footing diameter (B), expansive clay layer thickness (H) and presence of non-expansive clay are studied. The results proved the efficiency of (GPA) in reducing the heave of expansive soil and showed that the heave can be reduced with increasing length and diameter of (GPA). The heave of (GPA-Foundation System) is controlled by three independent variables these are (L/D) ratio, (L/H) ratio and (B/D) ratio. The heave can be reduced by up to (38 %) when (GPA) is embedded in expansive ...

The Storegga slide, released about 8200 years ago off the western coast of Norway, is a complex system of debris flows which occurred on the remains of previous Pleistocenic slides materials. Following geological mapping and interpretation of data gathered with geological and geophysical methods, the Storegga slide has been interpreted as consisting of a giant slide (volume z3100 km 3 and runout of about 400 km) followed by a swarm of progressively smaller events. The flow of the giant slide, object of the present, study, represents a dynamical enigma. Indeed, if one simulates the flow of the giant slide with simple non-Newtonian soil properties constant along the path, extremely small yield strength must be attributed to the material. This finding is incompatible with observations of the smaller slides, where the simplest non-Newtonian soil properties models work well with a yield strength more than one order of magnitude larger. A possible conclusion is that the material has charged its properties during the flow. Numerical simulations are conducted with a newly introduced model where in analogy with soil mechanical models, the material progressively loses strength during the flow. The model gives results comparable to field data if the shear strength decreases by at least a factor of 30 during flow.

Vertical movements calculated with the new design method for six case study cross sections in three different climatic zones in Texas were compared with the swelling movement predicted by the potential vertical rise (PVR) method, which has been used by the Texas Department of Transportation. Vertical movements included both swelling and shrinking. A review of assumptions that underlie the PVR method shows that two assumptions are unrealistic because they are not based on sound analytical principle and the three others cannot be supported by subsequent findings on actual Texas pavements or on soils of the United States. Pavement treatments were selected to provide acceptable predicted performance at high levels of reliability, and the vertical movements were calculated both at the edges of pavements and beneath the outer wheelpaths. The case studies were based on a variety of traffic levels, site conditions, and sample testing. The pavement treatments included limestabilized and cement-stabilized layers, removal and replacement with inert layers, and vertical and horizontal moisture barriers. The results of the case studies showed that the PVR method overpredicts the swelling movement that can be expected with the new method and does not predict shrinkage movement, which is important because that is an indicator of future longitudinal shrinkage cracking along the pavement edge.

A model was developed to predict pavement roughness caused by both expansive soils and traffic in terms of the serviceability index (SI) and the International Roughness Index (IRI). The model correlates the roughness analysis to the vertical movement estimated from the Texas A&M University suction-based method. The total vertical movement (including both swelling and shrinking) at the edge of pavement sections, the geometry of the pavement, site conditions, traffic, and the level of reliability were used as model parameters. Total movements calculated at the edge of pavement sections were based on a relationship between moisture content and suction, exponential suction envelopes, volume change coefficients, pavement treatments, and roadside conditions. Pavement treatments included vertical and horizontal barriers, inert soil, and lime-stabilized or cement-stabilized layers. The movements in wheelpaths at a distance from the edge of pavement were estimated on the basis of both field observations and the computed results of a transient finite element analysis. Transverse distribution of vertical movements on a pavement cross section was estimated. A relationship between IRI and SI was developed on the basis of surface profile measurements in several pavement study sections. The design equations that were developed for both flexible and rigid pavements include the effects of traffic and expansive soil and permit the selection of the desired level of reliability.