bluuebunny/crossref_metadata_2025 huggingface dataset:
Execução de Estacas em Solos Lareríticos
Authors: Abreu Paulo Sérgio Barbosa  , Décourt Luciano  , de Souza Filho João Mathias
Published: February 2025

Este trabalho apresenta um estudo da execução de estacas cravadas e/ou escavadas em solos lateríticos existentes em Brasília, capital do Brasil. É fato conhecido que as previsões de comprimento de estacas com base em fórmulas brasileiras de capacidade de carga são muito conservadoras quando essas estacas são executadas em solos de formação laterítica. Deu-se ênfase ao comportamento dos solos lateríticos na interface estaca-solo para explicar as diferenças de capacidade de carga das estacas, determinadas em provas de carga ou ensaios de carregamento dinâmico e aquelas obtidas pelos métodos convencionais de cálculo de capacidade de carga com base nos valores de SPT. Para tanto, foram escolhidas algumas obras no Distrito Federal, nas quais foram executados ensaios de carregamento dinâmico e/ou provas de carga estáticas. As estacas foram executadas em uma camada de solo argiloso cujos primeiros metros formam a camada de argila porosa vermelha do manto intemperizado superficial existente no Distrito Federal.
Laboratory study of the pressurized grouting in sand
Authors: Wang Qiong  , Wang Shanyong  , Sloan Scott William  , Sheng Daichao
Published: February 2025

Pressurized grouting technology has been widely adopted in ground improvement. In this study, a series small-scale laboratory pressurized grouting tests were conducted on loose sand under confined conditions, the effects of injection pressure, grout water/cement ratio and degree of saturation of soil (water content) were considered. By comparison of the injected grout quantity and the characteristics (shape and size) of grouted bulbs obtained two main different processes are found to be involved during pressure grouting process, i.e. densification by compaction grouting or fracturing by the injected grout. At a lower water/cement ratio of 0.5, spherical grout bulbs are generally obtained in the tested grouting pressure range and the compaction effect is prevalent; while, at a higher water/cement ratio of 1, the fracture starts to occur at a low grouting pressure, inducing a relative thin grout structure. It is also observed that more grout is injected at higher water/cement ratio due to the appearance of fractures. Regarding to the soil property, the degree of saturation (Sr) plays a significant role in the grout bulbs generation and development in relation to the soil water characteristics. With the Srincrease from 5 %, the mass of injected grout decreases followed by an increase after a threshold value of about 40%; on the other hand, compaction grouting seems to be dominant at the threshold Srvalue, while factures tend to appear at both lower and higher degree of saturation.
Medición del Cambio Volumétrico Total en Ensayos Triaxiales Utilizando Imágenes Digitales
Authors: Rodari Germán  , Garino Lucas  , Oldecop Luciano  , Zabala Francisco
Published: February 2025

En este artículo se presenta la aplicación de una técnica de medición directa de la variación de las dimensiones de una probeta de suelo en ensayos triaxiales basada en procesamiento de imágenes digitales (IP). La aplicación de esta técnica permite medir el cambio volumétrico en muestras no saturadas, sin necesidad de modificar la cámara triaxial. El equipo utilizado en la aplicación que se describe en este artículo consiste en una cámara fotográfica compacta y un dispositivo mecánico que permite tomar fotografías desde distintos ángulos alrededor de la probeta sin que se modifiquen el resto de las variables geométricas que influyen en el análisis. La técnica se ha calibrado durante ensayos triaxiales de muestras reconstituidas de arena, inicialmente saturadas y con drenaje durante la fase de aplicación del esfuerzo desviador (CD), en los que el cambio volumétrico se midió con una bureta graduada.
The influence of suction on the unconfined shear strength of a Compacted Residual Soil
Authors: Oliveira O.M.  , Marinho F.A.M.
Published: February 2025

This paper investigates the variation in the shear strength of a residual soil of gneiss using results from unconfined compression tests. The soil was prepared based on the standard Proctor compaction test. The specimens were statically compacted at three different regions of the compaction curve (dry side, wet side, and optimum point), in an attempt to generate three different structures from the same soil. A total of 54 unconfined compression tests were conducted. To enable evaluations at several suction levels, the specimens underwent either wetting or drying after compaction. The initial suctions were determined by the filter paper technique. The cohesion intercepts obtained from tests conducted on samples compacted at optimum moisture content and wet of optimum are similar and located above the intercept cohesion defined by specimens molded from the dry of optimum. The test results allowed defining three suction intervals; their influence on the shear strength presents different characteristics. The cohesion intercept obtained for the three molding conditions, initially shows a linear variation. After the air entry point, the intercept cohesion presented a non-linear behavior. For values of suction greater than 1000 kPa, the shear strength remains practically constant.
Geotechnical Instrumentation in Tailings Sand Dams
Authors: Illanes José  , Urquidi Jaime  , Figueroa Abraham  , Campaña José  , Morales Fernando
Published: February 2025

Geotechnical instrumentation is of great importance for assessment and evaluation of the safety of dams, and also for delivery of reliable information about their behavior during the construction, operation and post-operation stages, or in the face of any extraordinary event. In the case of tailings sand dams, the construction period coincides largely with their operation, this process sometimes extending over decades. That condition imposes some restrictions on the type of instrumentation and interferences of the dam operation with installation and long-term availability of the instrumentation system. In this article, the Chilean experience with geotechnical instrumentation considered for some high tailings sand dams is presented as an example. In addition, different technologies are discussed.
Ancoragens passivas. Casos de Obra (II)
Authors: Ferreira Sandra  , Sarra Pistone Raúl
Published: February 2025

O recurso a ancoragens passivas como elementos de estabilização/de reforço dos maciços constitui uma prática de corrente aplicação na geotecnia. Questões como o programa de ensaio, o sistema de reação e os dispositivos de leitura, constituem aspetos fundamentais para a garantia de resultados fidedignos e realistas, que por sua vez permitirão confirmar os pressupostos de projeto e inferir o comportamento deste tipo de elementos a longo prazo. Como elementos de suporte ao tema, são analisados casos de obras recentes.
Influencia de la Variabilidad Espacial de los Parámetros Mecánicos e Hidráulicos en la Estabilidad de Taludes
Authors: Muñoz Estefanía  , Cordão-Neto Manoel  , Ochoa Andrés
Published: February 2025

Debido a la gran complejidad e incertidumbre involucrada en la ocurrencia de movimientos en masa, no es posible preverla con precisión. Esta incertidumbre es consecuencia de la variabilidad espaciotemporal de los parámetros físicos del suelo y de los procesos que determinan las condiciones de frontera del problema. En este trabajo se analizó la influencia en el Factor de Seguridad (FS) de los parámetros que describen la resistencia del suelo, la curva de retención de agua y la curva de conductividad hidráulica no saturada de un talud hipotético. Inicialmente se realizó un análisis de sensibilidad utilizando el Método de Primer Orden Segundo Momento, donde se obtuvo que la cohesión, el ángulo de fricción, el valor de entrada de aire y el coeficiente de conductividad hidráulica saturada son los parámetros que determinan la estabilidad del talud analizado. Posteriormente, se hizo un segundo análisis para evaluar la variabilidad espacial de los cuatro parámetros, y se encontró que con el valor de entrada de aire y la cohesión se obtienen distribuciones de probabilidad con dispersión muy baja y moda similar a los valores determinísticos del FS, concluyéndose que su influencia es poca. Al variar la conductividad hidráulica, los valores de la moda se alejan del valor correspondiente al FS determinístico a medida que pasa el tiempo, aumentando la dispersión. Por último, al variar todos los parámetros al mismo tiempo, se obtuvo que el comportamiento del FS está altamente influenciado por la variabilidad de la conductividad hidráulica.
Urbanization Convenience Zoning Based on Geomorphology
Authors: Chavez José Alexander  , Šebesta Jiři
Published: February 2025

High intense rains, hurricanes and earthquakes constantly affect the Metropolitan Area of San Salvador, El Salvador. These natural processes along uncontrolled urbanization provoke landslides, erosion, collapse, liquefaction and drought increasing the environmental, economic and social losses. For this reason, an urbanization convenience zoning is proposed, based mainly on geomorphology with lithology and slope information. The results depend of the interpretation of aerial photos, satellite images, fieldwork and knowledge of the geodynamic of the territory. When compared with existing databases of denudation problems in the studied area, good results were obtained with this methodology; being the unconsolidated volcanic tephra deposits the more problematic region (badlands). The objective of the cartography is to identify the areas that need more research, improve the urban planning and recognize the processes that might affect existing infrastructure.
Physical Tests of Grain Contacts in Silica Sand: Static Fatigue
Authors: Wang Zhijie  , Michalowski Radoslaw L.
Published: February 2025

Freshly deposited or disturbed sands experience time-dependent increase in small strain stiffness and delayed increase in cone penetration resistance. Evolution of micro-mechanical properties at inter-granular contacts has been proposed as one of the key causes of time effects in silica sands. Previous work did not produce sufficient information about evolution of individual contacts, neither did it indicate how to relate such information to time-dependent behavior of particle assemblies. A static fatigue hypothesis was proposed recently, which identifies the delayed fracturing of surface textural features at contact as the key cause of time-dependent behavior of sands. Laboratory fatigue tests were carried out on an individual contact between a single grain and a flat stainless steel surface. The normal load was kept constant and the displacement of the grain relative to the stainless steel plate was monitored. It is evident that the response of the contact is time-dependent with decaying characteristics, which is consistent with the hypothesis of static fatigue.
Comparative Analysis of Reliabity Methods Applied to Rock Slope Stability
Authors: González Shand Gastón  , Sepúlveda Zamorano Jaime
Published: February 2025

Over the last years, it has become increasingly popular to include both deterministic (i.e., Factor of Safety) and probabilistic (i.e., Probability of Failure) methods in defining acceptability criteria for the design of operating mines and mining projects in Chile. There are many different methods available to calculate Probability of Failure, and each has its advantages and disadvantages. There are methods that are considered more rigorous nevertheless time-consuming to perform, while the less rigorous ones are generally simpler and faster to implement. This paper points out the most frequently used methods for calculating Probability of Failure of rock slopes in Chilean Practice. Among them, there are those that are approximations from Taylor Series, specifically the First Order Second Moment (FOSM), Monte Carlo and Latin Hypercube, Monte Carlo with Response Surface, and Point Estimate Method. In this paper Limit Equilibrium Modeling was chosen to develop a comparative analysis among the reliability methods in a hypothetical slope comprised of Mohr-Coulomb materials and a simplified rock slope from a Chilean mining operation.
Application of the Response Surface Methodology to 3DEC Analysis of Open Pit Slopes
Authors: Ortiz Rodrigo  , Silva G. Rodrigo  , Michalak Nelly
Published: February 2025

The aim of this work is to establish the response surface modeling (RSM) approach as a practical means to carry out probabilistic analysis of rock slopes with computationally intensive, large-scale numerical models that have proven reliable for assessing stability in complex, large open pit operations but which require considerable running time to estimate sufficient factor of safety (FoS) intervals. When compared to other well-established techniques such as Rosenblueth's Point Estimate Method (PEM), RSM a) facilitates the inclusion of a greater number of random variables, b) enables the sensitivity of individual variables to be readily ascertained, c) better translates such sensitivity into response skewness and d) allows for input variables to be characterized by explicit distributions based on sample histograms. This research centers on evaluating the three-variable probability of failure (PoF) response for two slope geometries through both RSM and PEM in order to establish the applicability of response surface modeling to real-world analysis scenarios. FoS estimations were undertaken in a 3DEC [1] model of similar complexity to those currently employed in assessing stability for mine plans. The results show that the RSM approach renders comparable results to PEM and that, provided proper estimation points are used, differences can be attributed to a better representation of the output distribution. Further modeling is also done to demonstrate PoF estimations with five random variables, a task which could not be reasonably contemplated by applying the point estimate method. The impact of analysis decisions such as estimation points and input variable probability density functions (PDFs) is further illustrated by means of a simple 2-variable model which allows for PoF to be attained through closed form solution or estimated through Monte Carlo simulation.
Finite Element Analysis in an Open Pit Mine Including Rock Faults
Authors: Aguilar Deysi Garcia  , Romanel Celso
Published: February 2025

This study investigates the influence of lithological discontinuities in the slope behavior of an open pit mine located in Peru. According to surveys of structural geology, the region of the mine has two large main systems of faults, separated from distances greater than 200m, and several secondary fractures, separated from distances greater than 20m. These faults can affect the stability of the slopes and turn themselves into preferred channels of water infiltration to the mining area. Field tests were carried out to obtain the properties of the intact rock, the quality of the rock mass and spatial orientation of the fault systems. The behavior of rock slopes, in terms of stability as well as the occurrence of displacements caused by excavations, is investigated using two and three dimensional numerical models based on the finite element method, considering the Mohr-Coulomb constitutive model for mechanical representation of the rock mass. Comparisons with the obtained numerical results show the effects of the presence of discontinuities on the slope behavior.
Weight Analysis of Influence Factors Based on SVM
Authors: He Shi-Jun  , Tang Ying-Li  , Zhang Ting  , Li Yu  , Xie Sheng-Dong  , He Pei-Min
Published: February 2025

Aiming at problems of the traditional weight analysis method, such as its subjection to the lack of a large number of known samples or experts' individual subjective consciousness, and according to properties of small sample theory and good generalization of support vector machine (SVM), a factor weight analysis algorithm based on SVM is presented in this paper. Firstly, according to the SVM model, weights of various influence factors over different time periods are calculated. Then, the variation of each weight over time is tracked. Finally, the change rule of each factor's weight is analyzed. This approach is applied to study the change regulation of factors' weights, which influenced the Enteromorpha disaster of the Yellow Sea in the year of 2013. The weight of each factor over different time periods is obtained, and various stages of the disaster process are divided according to the change regulation of weights. The above research works are proved using the data from 2012, and all results above show that the algorithm using SVM to get weight dynamically is effective and reliable.
Insights from Over a Decade of Electronic Publishing Research
Authors: Loizides Fernando  , Jones Sam A.M.
Published: February 2025

The work in this article presents findings from a text mining exercise of over a decade of research into electronic publication. We give readers insights into the past, present and possible future directions in a structured way, and further allowing them access to the extracted data in order to produce their own analysis and conclusion. We also produce our working methodology which can be replicated to produce systematic similar findings over the years as well as comparisons to other data souces.
Peer Review on the Move from Closed to Open
Authors: Schmidt Birgit  , Deppe Arvid  , Bordier Julien  , Ross-Hellauer Tony
Published: February 2025

Openness in peer review is no longer a terra incognita. However, there remains a need for further experimentation and careful evaluation of its advantages and disadvantages in practice. OpenAIRE, the European digital infrastructure for Open Scholarship, offers a unique environment for such experiments. This paper describes the design and early results of three such experiments, which are currently under development in close collaboration with selected publishing and repository communities.
Fading away vibrations during heavy tamping
Authors: Brandl H.  , Kopf F.  , Paulmichl I.
Published: February 2025

Heavy tamping (deep dynamic consolidation/compaction) has been increasingly used since the early Seventies. The paper reports on in situ measurements and theoretical investigations referring to fading away vibrations of the falling mass after each drop. This behaviour is essential for the soil – falling mass interaction and enables a site-specific optimisation of the heavy tamping technique. The field tests comprised acceleration measurements of the falling mass and the soil whereby the drop height was changed repeatedly. The amplitudes of the fading away vibrations provided a damping coefficient. The numerical calculations involved numerous parametric studies and were compared to the measurement results. Scope of the research project was to gain a reliable indicator for the compaction degree of the soil immediately after each blow, hence a method for continuous compaction control and documentation.
A study on the chemical and physical factors influencing compressive strength of grouting materials
Authors: Chun Byung Sik  , Yang Hyung Chil  , Sagong Myung  , Song Chi Yong
Published: February 2025

New type of tunnel driving method and tunnel aid method are not only in common use of subway constructions but also obtaining good results in Korea. Chemical groutings are one of the most popular methods for the ground improvement during tunneling. In this paper, a series of uniaxial compressive strength tests of grouting materials were carried out to examine the variation of compressive strength for homo-gel of grouting materials. It was observed that the compressive strength of Sodium Silicate-Cement Grouts varied depending upon mixing methods. The compressive strength of grouting materials increases with using Circulation-Grinding-Mixing Methods, and this trend is increasingly noticeable to a low molar ratio(calcium hydroxide/natrium oxide).
Experimental multi-layered water-saturated soils consolidation with the help of vertical drains
Authors: Konovalov P.A.  , Zekhniev F.F.
Published: February 2025

A program was implemented in practice to investigate heterogeneous soil beds stabilization by draining that enabled evaluation of the effect of various types of vertical drains in stratified beds with pockets and peat-containing clay loam seams that changed the conventional concept about impossibility of stabilizing such soil bases with drains.
Comparison between field monitoring and numerical results of a woven geotextile-reinforced soil retaining wall
Authors: Benjamim C.V.S.  , Bueno B.S.  , Zornberg J.G.
Published: February 2025

The use of geotextiles as reinforcements in soil retaining walls may result in significant benefits over the use of other reinforcement with other inclusions such as metallic strips or geogrids. However, the lack of a good understanding of the actual behavior of geotextile-reinforced structures, mainly regarding expected deformations, has prevented widespread utilization of this approach. To contribute for a better understanding of the behavior of geotextile-reinforced soil structures, monitoring of full-scale structures and a further characterization of the materials is needed. Accordingly, eight geotextile-reinforced soil structures were built and instrumented to analyze their behavior. This paper presents the field monitoring results and finite element analyses conducted to analyze the behavior of one of these structures. The results show that current design procedures are conservative, and that the displacements are smaller than expected. The numerical simulation results showed that the Finite Element Method (FEM) is a useful tool to predict the response of structures reinforced with geosynthetics, since the values collected from field instrumentation are very similar to those obtained from numerical simulation.
Behavior of a fiber-reinforced sand under large shear strains
Authors: Consoli Nilo Cesar  , Dal Toé Casagrande Michéle  , Coop Matthew Richard
Published: February 2025

Previous studies of fiber soil-reinforcement have shown significant improvement of the mechanical properties of soils, such as increased peak and post-peak strength, ductility and tenacity. However, studies of such materials have thus far been restricted to shear strains of approximately 20%, due to the restrictions of the standard equipment used (e.g. triaxial and direct shear tests). The objective of the present research was to study the behavior of fiber-reinforced sand submitted to very large displacements, to determine whether the improved strength would eventually deteriorate. Ring shear tests were carried out in order to investigate the effect of fiber micro-reinforcement of homogeneous sand over a wide range of strains and displacements. Polypropylene fibers (0.5% by weight, 12 mm in length, 0.023 and 1.394 mm thick) were randomly inserted in sand considering different relative densities. The results show the great potential of this kind of fiber when used as soil reinforcement, even at very large horizontal displacements.
Effects of geosynthetics reinforcement on bearing capacity and settlement of shallow foundations
Authors: Gualco D.  , Berardi R.
Published: February 2025

This paper reports the results of model loading tests performed on shallow footings resting on a double-layered deposit of Ticino Sand, a natural silica sand, with geosynthetic inclusions as reinforcement. The sand deposit is reconstituted by raining, using a travelling sand spreader apparatus at purpose developed, in two layers having different relative densities to simulate natural deposits. The soil is pluviated into a steel caisson (1.60x2.50x1.70 m) with reinforced wall; different model foundations, and types and assemblies of geosynthetic reinforcement are installed within. Analyses of the results in terms of bearing capacity, settlement and failure mechanisms are reported.
Unsaturated hydraulic properties for compressed air tunnelling by inverse modeling
Authors: Chinkulkijniwat A.  , Semprich S.  , Steger G.
Published: February 2025

A large scale element test was carried out to determine the unsaturated hydraulic properties of silty sand. To simulate air flow likewise in compressed air tunnelling, where air pressure is used to prevent water inflow during excavation, air pressure was upward injected from the bottom part of a saturated soil column. A series of constant head permeability experiments were conducted before to derive the saturated hydraulic conductivity. Thereafter the transient flow experiments were performed. UCODE in combination with TOUGH2 was employed to estimate the unsaturated hydraulic properties. To check the uniqueness of the solution, response surfaces were plotted and analyzed. Finally the derived parameters were employed in a 3D-numerical tunnel advance simulation to calculate the rate of air flow, which is one determining cost factor in the compressed air tunnelling method. The results show a very good coincidence with a comparable tunnelling project carried out in Munich.
Numerical modelling of unbound granular materials in thin pavements structures
Authors: Erlingsson S.
Published: February 2025

New pavement design methods are under development where the aim is to predict functional and structural conditions of the road over time. To be able to take advantage of these new design methods a better understanding of the ability to calculate the response of pavement structures due to vehicle load is needed were the mechanical properties of the constituent materials are properly presented. For thin pavement structures the granular materials, base and subbase layers, play an essential role in the overall structural performance. However they show a complex elasto-plastic behaviour under external loading. An instrumented thin surface dressed pavement structure has been tested in accelerated testing by using a Heavy Vehicle Simulator (HVS). The response of the structure due to traffic loading was measured and thereafter two different numerical techniques used to predict the structural behaviour, the Multilayer Elastic Theory (MLET) and the Finite Element (FE) method. Both linear and nonlinear elastic analyses have been carried out to simulate the response of the structure. It was found that analyses where the nonlinear base behaviour is taken into account gave better agreement with measurements compared to a linear elastic analyses. Based on the calculated response of vertical strain in the pavement structure as well as from results from Repeated Load Triaxial (RLT) testing a simple power law function is used to estimate the development of rutting in the pavement structure and compared to actual measurements. Good agreement was found between the actual measurements and the calculations.
Monitored construction of a high embankment on soft soil, reinforced by stone columns
Authors: Logar Janko  , Majes Bojan  , Ravnikar Turk Mojca  , Ločniškar Andrej
Published: February 2025

In 2003 a 11.5 m high embankment was constructed on approximately the same site where, 17 years previously, the soft alluvium deposits of the Rižana river failed beneath the 7 m high embankment, which was being built at that time at this location. The subsoil beneath the new Srmin embankment was reinforced by approximately 12 m high stone columns in order to ensure sufficient safety during and after construction, as well as small relative settlement between the embankment and the neighbouring deeply-founded structures during operation of the motorway. The results of design calculations have been compared with the measurements performed during construction of the embankment.
Filter performance test for dams containing cracks
Authors: Park Youngjin  , Brandon Thomas L.  , Duncan J. Michael
Published: February 2025

A new test procedure has been developed to evaluate filter performance when both the filter and the core (base) material have been cracked. This procedure allows the orientation of the crack to be horizontal or vertical, and accommodates flow in the horizontal and vertical directions as well. The applied hydraulic gradient and the thickness of the crack can also be varied. Two apparatuses have been constructed and tested. The smaller apparatus allows testing of truncated cylindrical test specimens that are 4" (10 cm) in diameter by 8" (20 cm) long. The larger apparatus allows testing of specimens that are approximately 12" x 12" x 12" (30 cm x 30 cm x 30 cm). An automated data acquisition system was developed to measure the pressures and flow rates through the test specimens as well as obtaining a video record of the filter performance. Initial tests have shown that the current filter criteria used by the U.S. Bureau of Reclamation, U.S. Army Corps of Engineers, and the National Resource Conservation Service provide filters that perform reliably even when cracked at the start of flow.
Reduction of the Cone Resistance caused by the installation of CFA piles
Authors: Hannink G.  , van Tol A.F.
Published: February 2025

In The Netherlands reduction coefficients are prescribed in order to account for the quality decline of the soil due to the installation of continuous flight auger (CFA) piles. In this paper the results of cone penetration tests (CPT's) are compared that have been made before and after the installation of CFA piles. The regulations and prescribed installation factors in the Dutch code NEN 6743 do not appear to be too conservative. The installation effect is significant, and not constant around the pile, and increasing with decreasing distances from the installed CFA pile.
Distributed parameter sensitivity of piles in nonlinear sand subjected to cyclic bending moment
Authors: Rahman N.  , Budkowska B.B.
Published: February 2025

The paper presents the formulation and numerical investigations of the sensitivity of maximum lateral deflection of a long pile embedded in p-y sand below the water table subjected to cyclic loading. The bending moment Mpof discrete variability is applied to the pile head. The cyclicity of the pile-soil system is tackled in a quasi-static fashion. The parameters involved in the p-y soil relationship as well as the pile bending stiffness are considered as the design variables of a continuous type. The system is analysed in the scope of variational calculus based on the virtual work principle. The virtual load method is employed in the determination of the first variation of generalized deformation. The formulation leads to establishing the new sensitivity functions that are spatial integrands connected with each of the design variables. The nummerical investigations are focused on the determination of sensitivity integrands of maximum deflection caused by the changes of the design variables of the system. The characteristics of spatial senstivities associated with each design variable of the system are discussed in detail.
Infiltration of a phthalate acid ester in a Brazilian tropical soil
Authors: Carrara S.M.C.M.  , Morita D.M.  , Boscov M.E.G.
Published: February 2025

Phthalate esters are used in industrial production of lubricants, glues, insect repellents and plastics. Among the phthalate esters, di-2-ethylhexyl phthalate (DEHP) was chosen because it is one of the most difficult to biodegrade. The aim of this work was to study the infiltration of DEHP into a Brazilian tropical soil, as preliminary step for the investigation of a bio-remediation technique. An experiment was carried out in an infiltration reactor. The soil was compacted inside the reactor at the in-situ dry unit weight, and DEHP was applied to the upper surface of the specimen as an emulsion. Water and soil samples collected in the reactor and analyzed by gas chromatography showed that DEHP was retained in the upper layer of the soil. In the case of an accidental spillage of DEHP in a soil with characteristics similar to the studied saprolite, a great fraction will be retained in a superficial layer, suggesting that containment techniques may be advantageous to reduce environmental impact.
Suction-controlled tensile strength of compacted clays
Authors: Zeh R.M.  , Witt K.J.
Published: February 2025

This paper represents a testing method to directly measure the suction-controlled tensile strength of compacted clays under a constant, initial soil structure. Test results of a medium plasticity clay are shown as an example. The induced suction is 0 to about 140,000 kN/m2. The tensile strength of the compacted clay reaches about 450 kN/m2as a maximum. In addition, analytic calculations based on the capillary theory show values in the same magnitude but underestimate the test results.
Geotechnology in harmony with the global environment: dream or deliverable?
Authors: Jefferis Stephan A.
Published: February 2025

This paper addresses issues raised by the sub-title of the conference “Geotechnology in harmony with the global environment” and considers how harmony may be assessed. It is argued that harmony with the environment cannot be achieved without sustainability and therefore sustainability must be considered as a first step. An attempt is made to develop a procedure to assess sustainability using life cycle assessment as a model and taking into account human values.
Application of geosynthetic barrier wall to containment of hydrocarbons in the Arctic
Authors: Mukunoki Toshifumi  , Rowe R. Kerry  , Hurst Paul  , Bathurst Richard J.
Published: February 2025

The effect of freeze-thaw cycles on the hydraulic conductivity of a geosynthetic clay liner (GCL) is assessed with respect to Jet Fuel A-1 (Arctic diesel). GCL specimens subjected to 0 and 5 freeze-thaw cycles and specimens recovered from a site on Brevoort Island in the Canadian Arctic after 3 years are examined. The GCL recovered from Brevoort Island had the lowest hydraulic conductivity with respect to de-aired water. Freeze-thaw cycles did not have a negative impact on hydraulic conductivity with respect to de-aired water. Freeze-thaw cycles did increase the hydraulic conductivity, k, with respect to Jet Fuel A-1. However, the hydraulic conductivity was still very low and the results suggest that the GCL can be expected to perform well as a hydraulic barrier in the medium term with respect to the effects of both freeze-thaw and permeation with Jet A-1. More testing is needed to assess long term performance.
Energy analysis and model tests on lateral flow induced by water film effect in liquefied ground
Authors: Kabasawa K.  , Kokusho T.
Published: February 2025

Considering that water films formed beneath low permeability sublayers in liquefied sand have a great influence on lateral flow mechanism, shaking table tests for saturated sand slopes are carried out. In a saturated uniform sand, flow deformation occurs almost exclusively during shaking, while in a sand slope with a sandwiched silt arc, post-shaking large flow deformation occurs in the upper layer by the water film effect. Results of energy analysis during the post-shaking flow reveal that the shear strength exhibited along the slip surface passing through the water film is only 20% of that of uniform sand. It takes non-zero value presumably due to the roughness of the slip surface. A close connection has been found between water film induced flow and dilatancy characteristics of sand beneath the low permeability seam.
Early warning system for landslides caused by high intensity rains during the El Niño
Authors: Marín-Nieto L.
Published: February 2025

Much geological and archeological evidence show that in the coast of Ecuador and Northern Peru, flourished ancient civilizations that later completely disappeared, by reason of intense rains and disastrous droughts. After El Niño phenomenon of the years 1997 and 1998, that destroyed towns, roads, agriculture in that region, the author has investigated the relationship between intense rain , its evolution and intensity, with the landslides occurred at the city of Guayaquil and other cities of the Ecuadorian coast, like base for a Early warning system. Many of the advances in the investigation were already presented by the author at several international meetings.
Failure mechanism and characteristics of soil subjected to interaction between soil elements in simple shear
Authors: Shigemura S.  , Tokue T.
Published: February 2025

To clarify shear behaviour in soil elements in a shear band which undergoes interaction between soil elements, principal stress rotation, etc, a simple shear test using a large specimen with five-coupled elements was conducted with the following results: the middle three elements produce the pure shear state by interaction, and show shear behaviours similar to those in a shear band and a two-step failure mechanism in which the overall failure follows the formation of local failure surfaces; one of Coulomb's and Mohr-Coulomb's failure criteria can derive the other of the two, etc.
Effects of irregular dynamic loads on soil liquefaction
Authors: Kim S.I.  , Park K.B.  , Park S.Y.  , Hwang S.J.  , Lee J.H.  , Choi J.S.
Published: February 2025

The sinusoidal types of cyclic loading have been commonly used for investingating dyamic responses of soils under earthquake loading, primarily due to simplicity. In this study, dynamic triaxial tests with different types of dynamic loadings including sinusoidal, triangular, incremental, and 9 real earthquake loadings were performed to investigate effects of loading type on liquefaction behavior. Based on test results, mobilization of the excess pore water pressure and the deviatoric stress is analyzed and compared. The phase transformation line from the effective stress path is introduced and investigated for generation of initial liquefaction. Stress damage concept based on the stress-time history and the cumulative energy is addressed and investigated as well.
Second phase construction project of Kansai International Airport
Authors: Furudoi T.
Published: February 2025

Kansai International Airport was constructed as a marine airport 5km offshore in Osaka bay so as not to burden urban dwellers with noise pollution. The second phase construction works are being performed even farther offshore than the first phase. To reclaim land over vast area and complete the island in a short period of time, maximum use is being made of the experience accumulated during the first phase construction works. And by introducing the latest technology and careful planning to procure the large quantity of materials and equipment required, construction works are proceeding in a smooth and efficient manner. This report shows an overview of the construction works of the second phase construction project of Kansai International Airport.
Activity, relative activity and Specific Surface Area of fine-grained soils
Authors: Cerato Amy B.  , Lutenegger Alan J.
Published: February 2025

Activity, as introduced in 1953 by Skempton, was defined as the ratio of plasticity index (PI) to the clay fraction (CF) of a soil and was used by Skempton to help distinguish mineralogic differences in fine-grained soils. While activity (A) provides an approximate method of delineating fine-grained soils by mineralogy, PI is not really a fundamental soil property. Conversely, Specific Surface Area (SSA) and Cation Exchange Capacity (CEC) are more fundamental soil properties that dominate engineering behavior of fine-grained soils. SSA and CEC are “inherent” soil parameters and may be combined with the clay fraction in order to help classify mineralogic composition of fine-grained soils. Two parameters are examined: 1. Specific Surface Area Activity (Sc), which is defined as the ratio of surface area to the clay content, and 2. Cation Exchange Capacity Activity (CECA), defined as the ratio of cation exchange capacity to the clay content. These two parameters show clear groupings of low, medium and high “activity” when used in relationship with other index parameters that may help explain fundamental clay behavior. The relationships between Scand CECA and engineering properties are presented and described. The results indicate that Specific Surface Area Activity and Cation Exchange Capacity Activity may be a more fundamental and convenient basis for describing the mineralogic composition of fine-grained soils.
Strain rate behavior of Mexico City soils
Authors: Díaz-Rodríguez J.A.  , Martínez-Vásquez J.J.
Published: February 2025

The purpose of the investigation reported in this paper was to study the influence of strain rate on stress-strain and strength relationships of Mexico City lacustrine soils from the Central Park site (Alameda). An isotropic consolidation test to define the yielding stress, σ'y(=95kPa), was done by triaxial-cell method. The paper describes results from 16 consolidated-undrained triaxial compression tests on Mexico City lacustrine soils. Specimens were consolidated to four confinement pressures (σ'c=40, 80, 160, and 300 kPa), and for each, σ'c, undrained shear was performed using four axial strain rates (1%, 5%, 100%, and 800%/h). The results show that the peak shear resistance increased about 336% in passing from the slow to the fast strain rate for the structured domain. For destructured domain, the increase was about 229%.
Modern technology introduced to safeguard old monuments in Angkor
Authors: Santoro V.M.
Published: February 2025

Some case histories of use of modern technologies and innovative materials for monument structures with damages provoked by geotechnical causes are presented.
Computational modeling of large deformations and the failure of geomaterials
Authors: Oka Fusao
Published: February 2025

Studies on constitutive modeling and numerical analysis methods have been well developed. Nowadays, numerical and analytical methods play a very important role in Geotechnical Engineering and in a related activity called Computational Geotechnics. Due to large deformations and failure, however, several issues are encountered in Computational Geotechnics. They include constitutive modeling and its calibration, mechanical instabilities: strain localization and progressive failure, the modeling of chemo-thermo-hydro-mechanical coupled behavior, and the verification and the validation of the mathematical modeling. In the present paper, we deal with the recent progress that has been made to solve these problems, in particular, the constitutive modeling of soil for rate-dependent models with structural degradation, strain localization, liquefaction of soil and their applications in the context of large deformations and the failure of geomaterials.
SPT sampler static penetration resistance in the case of a sandy soil
Authors: Aoki N.  , Esquivel E.R.  , Neves L.F.S.  , Cintra J.C.A.
Published: February 2025

This paper describes the performance of static load tests on the SPT sampler in sandy soils. The tests were performed soon after the measurements of the NSPTindex and the energy applied. It has been verified that the deformation potential energy assessed by the static test load-settlement curve is nearly equal to the work done by the system. Under these conditions, the efficiency based on the work done by the system non-conservative forces could be directly evaluated from the results of static load tests performed on the sampler.
Large compression of soil due to decay of structure during drained repeated shearing
Authors: Nakano M.  , Asaoka A.  , Nakai K.  , Tashiro M.
Published: February 2025

Huge volume compression of loose sand can be easily observed not under monotonie loading but under repeated shear stress application with small amplitudes, which is called compaction of sand. Although it takes long time the similar phenomenon is commonly observed even in highly structured natural clay, which has been called, for long years, secondary consolidation/delayed compression of natural clay. This study describes that these large-scaled volume compression observed both in clay and sand is due to the decay/collapse of soil skeleton structure that occurs with on going plastic shear deformation. Distinguishing the mechanical difference between sand and clay, the super/subloading elasto-plastic constitutive model still explains the mechanism of the volume compression of soils consistently.
A 2-D numerical study of the effects of anisotropy, ancillary drainage and geometry on flow through hydraulic fill mine stopes
Authors: Rankine K.S.  , Sivakugan N.
Published: February 2025

This paper utilises the two-dimensional finite difference package FLAC to investigate various factors affecting mine drainage including the effects of anisotropy, ancillary drainage and geometry on flow through hydraulic fill mine stopes. The numerical modelling carried out using FLAC shows that the horizontal ancillary drain provided at the bottom of the stope reduces the pore water pressure at all points within the fill substantially, however large the stope is, with the reduction being proportional to the length of the drain. For the case of stopes with horizontal ancillary drains at the bottom, a simple expression was developed to predict the maximum pore water pressure that always occurs at the bottom corner of the stope. The ancillary drain increases the hydraulic gradient and thus the rate of flow, resulting in quicker drainage of the stope. It was also shown that anisotropy in permeability of the fill material could also lead to a substantial reduction in pore water pressure. An increased knowledge of the factors affecting drainage will provide an increased level of confidence in design, more efficient mining procedures to be developed, and safer filling practices to be undertaken.
Bearing capacity of rectangular footings on two-layer clay
Authors: Zhu Ming  , Michalowski Radoslaw L.
Published: February 2025

While bearing capacity of footings has been a widely researched area, only recently have rigorous solutions to square and rectangular footings been attempted. A finite element analysis of square and rectangular footings over two-layer clay foundation soil is presented. Bearing capacity results are shown for a limited range of parameters. While the bearing capacity is distinctly affected by both the ratio of the strengths of the two layers and the depth of the weak layer, the shape factors are only dependent on the depth ratio.
Using the Sugeno Integral in Optimal Assignment Problems with Qualitative Utilities
Authors: Drissi Oudghiri Soufiane  , Perny Patrice  , Spanjaard Olivier  , Hachimi Mohamed
Published: February 2025

This paper is devoted to the assignment problem when the preferences of the agents are defined by qualitative utilities. In this setting, it is not possible to compare assignments by summing up individual utilities because the sum operation becomes meaningless. We study here the optimization of a Sugeno integral of the individual utilities. We show that the problem is NP-hard in the general case, but we also identify special cases that are solvable in polynomial time. Furthermore, we provide a mixed integer programming formulation in the general case, which leads to a compact formulation for k-minitive capacities.
A Probabilistic Logic Programming Approach to Automatic Video Montage
Authors: Aerts Bram  , Goedemé Toon  , Vennekens Joost
Published: February 2025

Hiring a professional camera crew to cover an event such as a lecture, sports game or musical performance may be prohibitively expensive. The CAMETRON project aims at drastically reducing this cost by developing an (almost) fully automated system that can produce video recordings of such events with a quality similar to that of a professional crew. This system consists of different components, including intelligent Pan-Tilt-Zoom cameras and UAVs that act as “virtual camera men”. To combine the footage of these different cameras into a single coherent and pleasant-to-watch video, a “virtual editor” is needed. This paper describes the development of such a component. We adopt a declarative approach, in which we build a model of the decision process that a human editor might follow to edit a video. To achieve a montage that obeys various cinematographic rules while at the same time retaining a natural, non-mechanical feel, we construct this model in a Probabilistic Logic Programming language. We demonstrate that the resulting system can be run in real-time and that it delivers montages that are almost indistinguishable from those made by a professional editor.