Abstract The study and understanding of the concepts related to critical state soil mechanics is relatively recent in Brazil, especially among practicing geotechnical engineers in the mining industry, where simpler solutions were traditionally adopted. This raises the necessity to develop studies capable of promoting discussions about the benefits of the approaches from the critical state theory. In this context, this research aims to evaluate the behavior of an iron ore tailings from the Quadrilátero Ferrífero through critical state computational models, considering the Modified Cam-Clay and NorSand model. The numerical results from the use of the models simulated the ductile/brittle behavior of the material in drained shear and it was observed that for loose samples both models produced similar results. The simulations in undrained shear, on the other hand, highlighted the differences between the models, with the NorSand showing a strength loss in undrained shear (strain-softening) whereas the Modified Cam-Clay Model exhibited a ductile behavior. In general, the NorSand model was the one that presented the best numerical response in relation to the experimental behavior, which may be linked to the use of the largest number of parameters, to the concept that particulate materials exist in a set of states and the silty characteristic of the material. Additionally, it was observed the difficulty to simulate the dense behavior of materials with the model, which may be associated with the formation of ‘shear bands’ during the experimental test and the complexity of modeling the occurrence of this phenomenon in virtual tests using the NorSand model. Brazil industry adopted theory context CamClay Cam Clay ductilebrittle brittle hand strainsoftening strain softening (strain-softening general parameters Additionally bands

Abstract Αn online questionnaire was developed to find out (i) whether geotechnical engineering instructors have available a variety of satisfactory educational material and (ii) the types of educational material they desire. The title of the questionnaire was phrased as “What Geotechnical Engineering Educational Material can we dream of?”, in order to convey that the main purpose of the survey project reported herein is to learn about these desired educational materials. In doing so, the survey also aims to assemble information on related issues, such as: existing educational materials, where do instructors search for them and how satisfied they are with available material. The questionnaire has 12 close-ended (four yes/no and eight multiple choice) and four open-ended questions. Of the 94 completed questionnaires received, 63 were deemed to be conscientious attempts to answer its questions and were analyzed in detail. The most revealing findings from the close-ended questions include the following. The majority of the instructors (52%) are not adequately satisfied with the material they use. Likewise, whereas a significant percentage have searched for additional material, a little less than half of them (45%) are not satisfied with material found. Respondents need materials for their lectures, materials to engage students outside lecture time and, to a lesser extent, materials to assess students. In terms of topics of interest, case studies and laboratory-related educational materials are the most popular. The online supplement of the paper includes broad-stroke and fine-stroke descriptions of desirable educational materials that provide directions for developing them. i (i ii (ii desire What of, , of?” so issues 1 closeended close ended yesno yes no choice openended open 9 received 6 detail following 52% 52 (52% use Likewise 45% 45 (45% found lectures extent interest laboratoryrelated laboratory popular broadstroke broad stroke finestroke fine of? 5 (52 4 (45 (5 (4 (

Abstract The use of problem-based and project-based learning is beneficial. The teaching-learning process requires the development of a critical, objective, and rational mind. This paper analyzes methodological experiments from the teaching-learning process carried out in the geotechnical area of the civil engineering program at three universities in the state of Pernambuco, Brazil, for more than 40 years. Three integrated experiments are presented. In the first experiment, undergraduate students in geotechnical engineering courses interacted with companies operating in the area, conducting laboratory and field tests and geotechnical instrumentation. The second experiment integrated students and teachers from different areas of the civil engineering program around a multidisciplinary project, while the third brought together undergraduate and graduate (master and doctoral) student research activities into a single project that extends from the development and construction of geotechnical equipment and applications of new soil improvement techniques to land use planning and occupation. This study shows the use of teaching-learning experiences carried out in geotechnical engineering, contributing to the development of technical skills and professional competencies of civil engineers. It contributed to the advancement of knowledge in the development of new equipment, soil improvement, testing techniques and in the use, planning and occupation of soils. The interaction between the university, society and government institutions in problem solving also contributed. problembased based projectbased beneficial teachinglearning teaching critical objective mind Pernambuco Brazil 4 years presented instrumentation master doctoral engineers soils university

Abstract Small-scale physical models of geotechnical problems are thought-provoking didactic tools that motivate students by arousing their curiosity and facilitating the understanding of physical phenomena and theoretical concepts. This work presents the development of an educational video about slope stability failures and its contributing factors. It shows several small-scale models built in a glass wall tank measuring 150 x 50 x 10 cm. Layers of fine gravel were placed on a sloping surface of polystyrene to represent a slope with a layer of residual soil on rock. Toy houses and cars were used to represent anthropogenic agents, and water with dye represents the groundwater flow. Each model depicts a different scenario of shallow slope failure. The objective of the video is to show that most slope failures in urban areas result from natural and anthropogenic factors. Several influence factors are shown: porewater level rise, excavation, surcharge application, and solid urban waste deposition. The 6-minute video has had more than 130,000 views on YouTube. Thanks to its simple and concise language, the video is shown in basic education and science museum, as well as in graduate and undergraduate courses. A questionnaire survey was carried out with undergraduate students to assess how helpful the video was for the learning process. This article explains the construction of the model, the video script, and the strategies for its use, as well as its reception. It was found that the video promoted motivational and learning benefits of providing context, establishing relevance, and teaching inductively. Smallscale Small scale thoughtprovoking thought provoking concepts smallscale small 15 5 1 cm rock agents flow failure rise excavation application deposition 6minute minute 6 130000 130 000 130,00 YouTube language museum courses process script use reception context relevance inductively 13000 13 00 130,0 1300 0 130,

Abstract To solve the problem that the mechanical behavior of undisturbed loess in seasonally frozen soil area is affected by freeze-thaw action, triaxial shear tests of undisturbed loess under freeze-thaw condition were carried out. The results show that the mechanical properties of undisturbed loess are greatly affected by factors including freeze-thaw process, water content, natural density and confining pressure. Freeze-thaw action has a certain impact on the failure surface shape and stress-strain curve. Before and after freeze-thaw, the shape of the shear failure surface is complex, including single oblique failure surface, double oblique failure surface, vertical failure surface, X-shaped failure surface, bulging failure, etc. And under the conditions of low water content, low confining pressure and high dry density, the stress-strain curve tends to be softened. Conversely, the curve tends to harden. Freeze-thaw action can make the stress-strain curve transition from softening to hardening. In addition, the freeze-thaw action significantly weakens the failure strength, shear strength, cohesion, initial tangent modulus and failure ratio of undisturbed soil, but does not change the internal friction angle obviously. Also, the heterogeneity of natural soil is also an important factor affecting the mechanical parameters, failure surface shape and stress-strain curve of undisturbed loess. freezethaw freeze thaw out process content Freezethaw Freeze stressstrain stress strain freezethaw, thaw, complex Xshaped X shaped etc softened Conversely harden hardening addition strength cohesion obviously Also parameters

Abstract As dams play a very important role in the optimum use of water resources, it is very important to keep them stable and the water stored in the reservoir. It is particularly important to investigate how water moves through rocks and the permeability and quality of the rock mass in structures like dams. Therefore, one of the issues considered in dam stability is monitoring the quantity of leaks. In this research, the engineering geological and geotechnical parameters of the rock mass for the construction of the Kurit Dam located in the city of Tabas in eastern Iran were evaluated. Initially, following the determination of geotechnical parameters, the engineering classification of the rock mass of the study area was carried out. In addition, in order to study and trace the water evacuation routes of the dam construction, two parameters of the RQD and Lugeon were studied and modelled. Analyses have been conducted to examine the permeability and rock quality index in three parts of the left and right abutment, the dam's axis and reservoir with geostatistics and kriging methods. Three-dimensional model of the construction of the Kurit dam was presented and the results were analyzed. Based on the results, the quality of the rock mass in the right and left abutments is arguably better than the dam axis and reservoir. Additionally, as the depth increases, the permeability decreases and the permeability is higher at shallow depths. The highest level of permeability is located at the surface and near the B H 4 borehole. resources Therefore leaks research evaluated Initially out addition modelled abutment s methods Threedimensional Three dimensional analyzed Additionally increases depths borehole

Abstract Seismic bearing capacity of strip footings is a challenging task for geotechnical engineers due to its stochastic framework instigated by the natural uncertainties incorporated into geotechnical properties and earthquake parameters. Consequently, the introduction of the random field theory into reliability analysis may provide power tools to succor designers check how reliable their designs. This paper aims to assess the seismic bearing capacity of shallow strip footings resting on soils with randomly varying parameters. Bearing capacity formulas for purely cohesive and cohesive-frictional soils are considered. The influence of the type of the autocorrelation functions (ACFs), the scale of fluctuations (SOFs) and the coefficient of variation (COV) of the random parameters are investigated. Statistical moments, probability density function (PDF) and failure probability (Pf) of the seismic bearing capacity are computed. It is shown that the Single Exponential (SNE) ACF is the most appropriate function to characterize the spatial variability of the soil properties since it provides conservative results. On other hand, the results indicate that the increase in the coefficients of variation (COV) of the cohesion or the friction angle increases the variability of the seismic bearing capacity while this variability remains unaffected when the COV of the seismic coefficient increases. The results also highlight that the effect of the vertical SOF on the PDF and the failure probability is much more significant than that of the horizontal SOF. In addition, the mean seismic bearing capacity fluctuates slightly as the horizontal or vertical SOF increases so that the increment of variation is between 0.4% and 2% for the both two soil types. Consequently designs cohesivefrictional frictional considered ACFs, ACFs , (ACFs) SOFs (SOFs (COV investigated moments (PDF Pf (Pf computed SNE (SNE hand addition 04 0 4 0.4 2 types (ACFs 0.

Abstract The aim of the current study is to investigate the influence of consecutive wetting and drying cycles on the free swelling and swelling pressure properties of a potentially expansive soil. The investigated sample consisting of high-plasticity inorganic clay with high consistency-limit values and extremely high swelling potential. The adopted methodology comprised free swelling and swelling pressure tests – based on the post-swelling loading method, under 0.5 kPa overload. Both tests were conducted in a cyclic manner by implementing eight wetting and drying cycles. Results have shown that the wetting and drying cycles acted as agents influencing the swelling pressure and free swelling properties of the expansive soil. It was found that the expansive soil sample, when moistened and then dried to its initial moisture content, time and again, showed higher values of swelling pressure and free swelling at the first moistening cycle. It was also observed that the expansive soil sample decreases its expansive behavior as the number of wetting and drying cycles increases. highplasticity plasticity consistencylimit consistency limit potential postswelling post method 05 0 5 0. overload content again cycle increases

Abstract With the advent of critical state Soil Mechanics (CSSM), the void ratio began to be recognized as a key parameter, along with the stress state, which defines the mechanical behavior of soils and other particulate geomaterials by using the state parameter. The state parameter is the difference between the current and critical void ratio so that its definition requires the critical state line (CSL) identification. This work presents numerical calibration results, using the NorSand constitutive model, from three sets of triaxial compression tests selected from the literature. The SIGMA/W module of the Geostudio® System was adopted to perform the simulations of the triaxial compression tests, and the results showed adequate fit between real tests and numerical simulations. The parameters necessary for the modeling with NorSand model, defined from the numerical calibration, were used in a stress-strain evaluation of a hypothetical upstream tailings dam. These simulations allowed the evaluation of the differences in the tailings storage facility (TSF) responses in terms of both deformation behavior and flow liquefaction instability. Flow liquefaction instability is described in the literature as a complete loss in shear strength and the development of excessive strains due to the contractive response of tailings when subjected to low confining stress. The results suggest that the use of the NorSand model is, in general, a good option to reproduce the typical strain-softening behavior of such structures. Furthermore, it was clear the high sensitivity of the constitutive model parameters, drawing attention to the importance of best laboratory practices for carrying out triaxial tests to obtain reliable parameters for NorSand modeling. CSSM, CSSM , (CSSM) CSL (CSL identification SIGMAW SIGMA W Geostudio stressstrain strain dam TSF (TSF general strainsoftening softening structures Furthermore (CSSM

Abstract The Federal University of Goiás (UFG) and the University of Brasília (UnB), in partnership with the company Eletrobras Furnas, have developed research and, based on this, extension projects aimed at education in a broad sense, in which they seek to disseminate and popularise technical-scientific knowledge. This paper aims to present and evaluate educational actions carried out in the area of soil science and geotechnics applied to engineering, geography, and the environment. To do so, the educational experiences developed within the scope of two extension projects are shared. Besides that, the relevance of publishing books and primer, with language adapted to lay society, within the scope of research projects, is analysed. The results collected regarding the effectiveness of the extension actions as a tool for learning point to a positive evaluation by the students. Furthermore, social networks are an important tool for scientific dissemination and have the potential to disseminate knowledge more widely than in a classroom course. By comparing the number of citations in Google Scholar of the books and booklets with the papers arising from these projects, one can observe the reach of this type of publication, although its purpose is the popularisation of science, with reach in places not considered in the technical-scientific publication metrics. Finally, for effective scientific development, it is necessary to have public policies, effective interaction between universities, research centres and schools, and the participation of professional associations, funding and evaluation agencies, Education Departments and the Ministry of Education, Science, Technology, and Innovation. UFG (UFG UnB, UnB , (UnB) Furnas sense technicalscientific technical engineering geography environment so shared that primer society analysed students Furthermore course metrics Finally development policies universities schools associations agencies Science Technology Innovation (UnB

Abstract Terzaghi (1943) developed an empirical method for primary consolidation due to a load applied at constant rate (ramp load) until the end of construction at time tc. The method considers that the settlement at a time t during construction, can be evaluated admitting the load applied instantaneously at time t/2. In this research, two alternative modifications are proposed for this Terzaghi’s empirical recommendation. The first one is based on a variable fraction of time t and the second modification keeps Terzaghi’s suggestion (t/2) but makes reductions in the average degree of consolidation Uv. Computed results for different construction time factors Tv were compared to Olson (1977) analytical solution. The first approach yielded a maximum difference of approximately 2.40% while the second alternative gave results that are practically the same as those calculated by Olson’s solution. The validity of these new approaches was also proven by reproducing odometer test results with good agreement. 1943 (1943 ramp tc t2 2 t/2 research Terzaghis s recommendation (t/2 Uv 1977 (1977 solution 240 40 2.40 Olsons agreement 194 (194 t/ (t/ 197 (197 24 4 2.4 19 (19 (t 2. 1 (1 (

Abstract Modern tunnel design in urban areas heavily relies on numerical modeling to assess excavation stability and predict ground movement. Recent advancements in soil modeling, hardware, and software have facilitated the development of sophisticated 3D models within tight schedules. Urban tunnels are often shallow and excavated in challenging ground conditions, with proximity to existing structures and infrastructure. Consequently, numerical modeling of such tunnels involves highly nonlinear analyses with complex boundary conditions. Despite the widespread use of numerical modeling in tunnel research and design, there is a lack of publications addressing modeling procedures to ensure accurate and reliable results for highly nonlinear shallow tunnel analyses. This paper investigates the requirements for accurate results for highly nonlinear shallow tunnel analyses. The Finite Element Method (FEM) is employed with different mesh refinements and element types. The study focuses on the hypothetical excavation stability scenario explored by Carranza-Torres et al. (2013). Tunnel stability is assessed using Caquot's analytical solution based on the lower bound theorem of plasticity, as well as FEM modeling with the strength reduction method. The FEM numerical solution, which approaches the exact solution for the problem, provided a factor of safety slightly larger (2.3%) than Caquot's lower-bound solution. The results of the FEM modeling indicate that a significantly less refined mesh is required to achieve accurate results for highly nonlinear shallow tunnel analyses when adopting 2nd-order elements (i.e., quadratic interpolation) instead of 1st-order elements (i.e., linear interpolation). This study improves our understanding of FEM modeling requirements and provides practical insights regarding the numerical modeling of highly nonlinear shallow tunnels in urban areas. movement hardware D schedules conditions infrastructure Consequently (FEM types CarranzaTorres Carranza Torres al 2013. 2013 . (2013) Caquots Caquot s plasticity method problem 2.3% 23 2 3 (2.3% lowerbound 2ndorder ndorder 2nd order nd i.e., ie i e (i.e. interpolation 1storder storder 1st st interpolation. 201 (2013 2.3 (2.3 i.e. (i.e 20 (201 2. (2. i.e (20 (2 (

Abstract Environmental conditions have become a concern when involving the use of Geosynthetics clay liners (GCLs) as leachate barriers, particularly because they can be subjected to daily thermal cycles during construction and operation of landfills, which can affect their properties. This paper investigates the hydration behavior of a nonwoven geotextile carrier-GCL in contact with lateritic subsoils under isothermal and simulated thermal conditions as commonly found in tropical regions. A thermal insulate testing box was used to shelter an instrumented liner landfill allowing the investigation of thermal and hydraulic responses during hydration. Lateritic subsoils were observed not to provide high levels of GCLs hydration under isothermal conditions, whereas thermal daily cycles led to capillary break that restricted the moisture uptake at the interface between subsoil and the nonwoven geotextile carrier. Higher values of subsoil initial moisture contents were found to be significant to reduce capillary effects and to allow some GCL hydration. The poor hydration demonstrated to be critical in terms of GCL hydraulic behavior. (GCLs barriers landfills properties carrierGCL carrier regions