bluuebunny/crossref_metadata_2025 huggingface dataset:
Autonomous repair of polymer networks by stress-induced catalyst activation
Authors: Göstl R.  , Sijbesma R.P.
Published: February 2025

Autonomously self-repairing and -healing processes will play a key role in the development of future ‘smart’ materials and devices. Here we present the development of a novel second generation Grubb's catalyst that can be activated through the application of mechanical force in solution as well as in the solid state. We show thorough kinetic analyses as well as extensive optimization for the improvement of the catalyst's activity and lifetime and have eventually translated the concept to the solid state. It could be successfully proven that mechanical activation initiates the ROMP to linear as well as cross-linked polymers in the solid state and by this we present for the first time the autonomous repair of a material that relies on the mechanochemical activation of catalysts on the molecular level. We are certain that this tailor-made prototypical catalyst-system establishes an important step for the implementation of self-healing materials in an everyday environment and are confident that this novel motif will stimulate future research on this field.
Foreground Extraction Method for X-ray Imaging Auxiliary System
Authors: Zhan Pei-Ru  , Su Shun-Feng  , Chen Ming-Chang
Published: February 2025

The paper proposes a foreground extraction method for X-ray imaging auxiliary system. In the radiographic projection process, patient will put their palm on the receptor board. When the depth histogram of palm image and receptor board image are very similar, traditional method is hard to obtain satisfied segmentation results. Therefore, the paper utilizes the improved maximum filter to distinguish the palm image and receptor board image from the original image. In the experimental results, we compare Otsu method with our proposed method. It is evident that our proposed method can obtain a more complete palm image than the Otsu method.
Realization of an Energy-Based Ant Colony Optimization Algorithm for Path Planning
Authors: Lee Kuan-Tung  , Huang Shih-Hua  , Sun Shih-Hsun  , Leu Yih-Guang
Published: February 2025

In this paper, we propose an energy-based ant colony optimization algorithm for path planning. Because the shortest path does not guarantee the optimal energy-conserving way, this paper utilizes the ant colony optimization algorithm to acquire the optimal energy-conserving path. For battery-powered electric vehicles, the energy consumption depends on the road condition. Therefore, according to the road condition, the update law with energy pheromone is obtained. Finally, computer simulations and real road experiments of the battery-powered electric vehicle were conducted to verify the efficiency of the proposed method.
Stable Carbon and Nitrogen Isotopes as Indicators of Organic Matter Sources in Ishikari River System
Authors: Kumar Jha Pawan  , Masao Minagawa
Published: February 2025

The bed sediment and particulate organic matter (POM) samples collected from Ishikari river and its tributaries were analyzed for organic C, total N and their isotopic composition. The δ13C of POM in Ishikari river ranged from −34.6 to −24.6‰, suggesting that contributions from the C4-based vascular plant organic matter was negligible and detritus from C3plants and C3plant dominated soil and fresh water phytoplankton contributes the POM load in Ishikari river system. The δ15N isotopic ratio of POM ranged from −4.8 to +15.8‰, with an average of 4.5±4.3‰ in the Ishikari river system. The δ15N ratio of sediment samples range from −0.92 to +8.71‰, with an average value of 3.8±2.5‰ in the Ishikari river system. The δ15N isotopic ratio of POM samples taken from Barato lake – an Oxbow lake in Ishikari river – shows strong inverse relation with the dissolved nitrate concentration in the lake water indicating that significant portion of the POM being derived from phytoplankton that were utilizing nitrate that had been subjected to denitrification. The molar C/N ratio of POM sample ranged from 5.3 to 17.8, with an average of 9.8±2.8 in the Ishikari river system. The correlation plots between molar C/N ratio and N isotopic ratio indicates that most of the POM samples fall between mixing zone of aquatic source (phytoplankton) and terrestrial source (soil organic matter and plant detritus) in Ishikari river system.
On the Classification of Industrial SAT Families
Authors: Ansótegui Carlos  , Bonet Maria Luisa  , Giráldez-Cru Jesús  , Levy Jordi
Published: February 2025

The success of portfolio approaches in SAT solving relies on the observation that different SAT solving techniques perform better on different SAT instances. The Algorithm Selection Problem faces the problem of choosing, using a prediction model, the best algorithm from a predefined set, to solve a particular instance of a problem. Using Machine Learning techniques, this prediction is performed by analyzing some features of the instance and using an empirical hardness model, previously built, to select the expected fastest algorithm to solve such instance.
Spatial Variability of Subsurface Soil Conditions Causing Roadway Settlements
Authors: Bilgin Ömer  , Arens Kevin  , Salveter Mark  , Dettloff Alexander
Published: February 2025

Settlement of problematic soils constituting the roadway subgrade may result in pavement distress and structural failure, requiring periodic pavement patching and resurfacing. Many of these problems occur as a result of the settlement of soft cohesive and organic soils. Due to the extent of roadway projects and the limited frequency of boring locations, spatial variability of subsurface soil conditions, and sometimes due to an inadequate extent of exploration, these problematic soils may not be identified suitably during subsurface explorations. An extensive subsurface exploration program was implemented for detailed characterization of subsurface conditions for a relatively short section of an existing roadway experiencing continuing settlements. This paper presents some of the exploration results, assesses the spatial variability of the subsurface soil conditions, and comments on the effect of spatial variability of subsurface conditions on the roadway's performance.
Random Sets-Based System for Geotechnical Soundings Density Estimation
Authors: Boumezerane Djamalddine
Published: February 2025

The required number of soundings for geotechnical site investigation depends on different factors such as geology of the site, soil variability and the type of project to build. Indications on the number of soundings are given in codes of practice (Eurocode 7...) but they focus mainly on a minimal number which depends only on the area of the project.
System Failure Probability of c-ϕ Soil Slope Stability using Vertical Random Fields
Authors: Li Liang  , Chu Xuesong
Published: February 2025

The need for system failure probability, pf, of soil slope stability that takes into account the spatial variation of soil properties has been acknowledged by the geotechnical profession. The spatial variations of cohesion and friction angle for a c-ϕ soil slope were modeled by one dimensional vertical random field respectively. The cross correlation of these two random fields was modeled by a simple decaying function. The effect of random field discretization (i.e., local average size) on pfwas studied. The results show that the influence of local average size Δy on pfcannot be ignored (relative error is greater than 10%) if ignoring variance reduction and correlation between local averages for the cases that the ratio of Δy to scale of fluctuation is greater than 0.2. The influence of local average size Δy on pfis negligible (relative error is smaller than 10%) if variance reduction and correlation between local averages are considered for the cases that the ratio of Δy to scale of fluctuation is less than 1.0. It is highly recommended to take into account the variance reduction of local averages and correlation between local averages using random fields for the calculation of pf. The ratio of local average size Δy to scale of fluctuation is smaller than 1.0 if no more than 10% relative error is expected.
Influence of Model Accuracy on Load and Resistance Factor Calibration of Steel Strip Walls
Authors: Miyata Yoshihisa  , Bathurst Richard J.  , Otani Yoshinori
Published: February 2025

This study examines the load and resistance factor design calibration of steel strip reinforced soil walls (SSW). The tensile loads and pullout capacities of reinforcement strips that are measured using full-scale tests reported in the literature are compared with predicted values using analytical models recommended by the Public Work Research Center (PWRC) in Japan. Modified load and resistance models are proposed in this study. These models preserve the general form of the PWRC equations, but the factors variables in the equations are adjusted to improve accuracy. The adjusted variables are empirical and are selected by back-fitting to measured loads, to achieve a load bias mean equal to one and a low coefficient of variation of bias values. This study elucidates the influence of model accuracy on the load and resistance factor calibration of SSWs.
Interactive Evaluation of the Reliability of Engineered Slopes Utilising Multi-source Monitoring Information
Authors: Zhang Limin  , Li Xueyou  , Li Dianqing  , Zhou Chuangbing
Published: February 2025

Important engineered slopes are often heavily instrumented and their performance routinely monitored through these instruments. The evaluation of the safety of the slopes based on the monitored information is however a challenge. A systematic method is presented in this paper for evaluating the slope safety by combining multi-source monitoring information with underlying physical mechanisms. First, a Bayesian network with continuously distributed variables for a slope involving the factor of safety, multiple monitoring indexes and their influencing soil or rock model parameters is constructed. Then the prior probabilities for the Bayesian network are quantified considering model and parameter uncertainties. After that, multi-source monitoring information is used to update the probability distributions of the soil or rock model parameters and the factor of safety or failure probability using Markov Chain Monte Carlo simulation. Two rock slope examples are worked out to illustrate the proposed methodology. A non-intrusive stochastic numerical method is used in the reliability analysis in the examples.
Limit State Imprecise Interval Analysis in Geotechnical Engineering
Authors: Marques Sónia H.  , Beer Michael  , Gomes António T.  , Henriques António A.
Published: February 2025

The first applications of nonprobabilistic interval analysis in geotechnical engineering have been recently explored. In fact, the solution of practical problems in this field often requires judgement based on limited data and interval analysis has become a research area formally motivated by input information characterised by imprecision. Whenever no information apart from bounds is available, intervals may be considered in the form of a model noted that they are among the most widely used analytical tools to describe uncertainty by using nonprobabilistic approaches. However, the application of a pure interval analysis to engineering problems may lead to large overestimation due to the dependency phenomenon and meaningful results are only obtained when a decision is based on threshold values. A mixed approach that admits imprecise information as well as probabilistic information is therefore desirable. In this paper the conventional probabilistic approach to uncertainty is extended to include imprecise information in the form of intervals. For demonstration, results are provided for a strip spread foundation designed by the Eurocode 7 methodology, wherein the shear strength parameters of the foundation soil are implemented as intervals and then combined with other uncertain parameters in the form of bounded random variables under dependence. A limit state imprecise interval analysis for safety assessment is then presented in the format of a sensitivity analysis.
Reliability Analysis of Infinite Slopes under Random Rainfall Events
Authors: Yuan Ji  , Papaioannou Iason  , Straub Daniel
Published: February 2025

Landslide events often occur after rainfall events during which the pore water pressure builds up within surficial soil layers, leading to shallow slope failure. The spatial variability of the permeability parameters of the soil causes high gradients in pore water pressure when the rainwater infiltrates into the slope. In this paper, we compute the reliability of infinite slopes under random rainfall events considering the spatial variability of the soil permeability. We model the infiltration process in HYDRUS-1D, which applies a numerical solution of Richard's equation, and combine this with a one-dimensional random field model of the hydraulic conductivity of the soil. The rainfall event is characterized in terms of its duration and average intensity and modeled through a self-similar random process. The reliability analysis of the infinite slope is based on the factor of safety concept for evaluating slope stability. To cope with the large number of random variables arising from the discretization of the random fields, we evaluate the slope reliability through subset simulation, which is an adaptive Monte Carlo method known to be especially efficient for such high dimensional problems. We study the influence of the duration and average intensity of the rainfall event on the slope reliability.
Design of Deep Supported Excavations: Comparison Between Numerical and Empirical Methods
Authors: Katsigiannis Georgios  , Schweiger Helmut F.  , Ferreira Pedro  , Fuentes Raul
Published: February 2025

This paper focuses on the derivation of design prop loads for supported excavations in stiff clay with increasing excavation depth and number of prop levels. For multi-propped walls there are a number of empirical graphs to obtain the design prop forces. CIRIA C517 (Twine & Roscoe, 1999) enhancing Terzaghi & Peck's work (Terzaghi & Peck (1967) and Peck (1969)) and making it more relevant in the UK practice, suggests the Distributed Prop Load (DPL) method based on 81 case histories and field measurements of prop loads. Similar guidance and empirical graphs exist in other countries such as the EAB Recommendations in Germany (Recommendations on Excavations: EAB, 3rd Edition, 2014). The design prop loads derived by empirical graphs (both CIRIA and EAB which are widely used in the UK and Germany respectively) and Finite Element methods are compared in the context of Eurocode 7 requirements. The German recommendations give prop loads in better agreement with the numerical analysis results. Suggestions are made to update the CIRIA guidance in line with the German recommendations and give different shapes of pressure distribution for supported walls with different number of prop levels. This can result in more realistic predictions of prop loads for upper layers, particularly in deep excavations, and hence more economic design.
Monitoring Analysis of Foundation Deformations of the Botlek Lifting Bridge
Authors: Rijneveld B.  , Jacobse J.A.
Published: February 2025

A new lifting bridge is being constructed crossing the river Oude Maas in the Rotterdam harbour area in the Netherlands. Since foundation deformations of the main piers have a large influence on the performance of the superstructure, extensive deformation analyses have been performed during the design phase. In order to minimise the risks and optimise the costs, the observational method was applied. Based on an extensive monitoring system the deformations of the bridge were monitored. Since the deformations remained well below the intervention values no control measures were necessary. Valuable lessons with respect to dealing with uncertainties in the analysis of measuring and estimation of residual settlements were obtained.
Risk Management of a Complex Remediation of the Former Feijenoord Gasworks Site in Rotterdam
Authors: de Vries M.  , Hulsbos K.  , Blaauw J.
Published: February 2025

This paper will show how the project's geotechnical risk profile was put into design and contract, the experience of the risk monitoring and risk measures, followed by a short evaluation.
Reliability Analysis of an Anchored Contiguous Pile Wall in Ankara Clay with the Random Set Finite Element Method
Authors: Akbas Sami Oguzhan  , Kokten Ozgen
Published: February 2025

A deep excavation application characterized by imprecise data and lack of adequate information is used to demonstrate the efficiency, applicability, and validity of the random set theory in combination with finite element method (RS-FEM). A case history of an anchored contiguous pile wall in overconsolidated fissured Ankara Clay constructed for supporting the 15 m deep basement excavation of a nursing house in Seyranbaglari district of Ankara is considered. Existing buildings around the excavation area necessitated a careful examination of the wall deformations and the reliability of the system as a whole. However, the geotechnical parameters of the soil had to be estimated combining the results of very limited in-situ and laboratory tests with those obtained through previous experience of finite element analyses under similar conditions, i.e., expert knowledge. Plane strain finite element analyses were then performed to predict the contiguous pile retaining wall behavior. The parameters in the random set finite element model were chosen according to sensitivity analyses. Most likely bounds of the wall horizontal deformations were compared with those obtained from inclinometer readings. As suggested by previous case histories, wall deformations were observed to fall within the lower third of the range predicted by RS-FEM.
Geotechnical Reliability Analysis Involving Spatially Autocorrelated Soil Properties
Authors: Low Bak Kong
Published: February 2025

Spatial autocorrelation (also termed spatial variability) arises in geological material by virtue of its formation by natural processes acting over long geologic time (millions of years). This endows geomaterial with some unique statistical features (e.g. spatial variability) not commonly found in structural material manufactured under strict quality control. For example, by the nature of the slow precipitation over many years of fine-grained soil particles in water in nearly horizontal layers, two points in close horizontal or vertical proximity to one another are likely to be more positively correlated (likely to have similar undrained shear strength values, for example) than two points further apart in the vertical direction. This paper presents reliability analyses involving spatially autocorrelated soil properties for a laterally loaded pile and two soil slopes. Information on parametric sensitivity from reliability analysis, the differences and similarities between reliability-based design and Eurocode 7 design approach, and insights from reliability analysis, will be discussed.
Probabilistic Slope Stability Analysis using RFEM with Non-Stationary Random Fields
Authors: Griffiths D.V.  , Huang J.  , Fenton G.A.
Published: February 2025

Using recently obtained deterministic results as a benchmark, probabilistic slope stability analyses have been performed on an undrained slope using the random finite element method (RFEM). Non-stationary random fields have been generated with linearly increasing mean undrained strength and a constant coefficient of variation. The influence of input spatial correlation and variance on the probability of slope failure in a test example is reported, and particular attention is drawn to the solutions corresponding to extreme values of the spatial correlation length.
Reliability Assessment of Digital Terrain Models Drawn from Digital Photogrammetry
Authors: Colantonio Fabio  , Rainone Mario Luigi  , Orsini Loris Emanuel
Published: February 2025

The modern techniques of Digital Photogrammetry are used to reconstruct Digital Terrain Models (DTMs) from photosets taken by commercial digital cameras. The algorithms are based on the Multiview Stereo Vision (MVS) which draw a 3D model in the space through the internal setting of the digital photosets. In this study, two open source codes, VisualSfM and CMP-MVS are used to combine the photosets to build the DTM of the Civitaluparella (CH) quarry wall. This latter is compared with the reference DTM reconstructed by a Laser Scanner device (in this application the Long-Range Topcon GLS-1500 laser scanner has been used). The comparison evidences spatial errors about ±0.1m along y and z directions and ±0.2m along x direction for the DTM drawn by the Digital Photogrammetry for the vertical quarry wall. Hence, these outcomes confirm the reliability of the Digital Photogrammetry codes as fast and cheap tool for drawing accurate Digital Terrain Models. These DTMs can be used for generating Digital Elevation Models (DEMs) for engineering geological applications such as slope stability analyses
Effect of Prior Knowledge on Site-Specific Selection of Regression Model for Characterization of Geotechnical Properties
Authors: Aladejare Adeyemi Emman  , Wang Yu
Published: February 2025

During geotechnical site characterization, many geotechnical properties might be difficult to measure directly and have to be estimated using indirect measurement and regression models. For example, when there is no possibility of direct compression test, geotechnical engineers and practitioners may utilize regression models (i.e. equations) to estimate the uniaxial compressive strength, UCS, of rock from point load index, Is(50). However, there are many equations relating Is(50)to UCS in the literature. This leads to the problem of how to select the most appropriate model for a particular rock deposit out of the numerous models available. This study presents a method that rationally compares different regression models and selects the most appropriate model for a specific site or deposit considered herein. The most appropriate model is selected using only a limited number of site-specific Is(50)data. The selected model is then used in a Bayesian framework to integrate the prior knowledge about UCS with the limited number of site-specific Is(50)data available for probabilistic characterization of UCS. The approach is shown to perform properly, particularly when the prior knowledge reflects information from the site.
Observational Method, Case A2 Maastricht
Authors: van Dalen J.H.  , Servais R.  , Boone D.C.
Published: February 2025

The A2 tunnel in Maastricht has been built within a dry building pit with a maximum depth of 22 meters with sheet pile walls, suspended in a cement bentonite trench supported by struts at 2 to 4 levels. Dewatering is done by deepwells. The excavation reaches into Limestone layers so the maximum mobilized passive resistance of the sheet pile wall is depending on the strength parameters of these layers. In the design stage of the project uncertainties occurred about both strength parameters and permeability of the Limestone for a large part of the project. These uncertainties could only partly be reduced by additional soil investigation and in-situ tests, but they were vital for the design of the retaining walls. To combine economical implementation of the project with a very favourable risk profile the “Observational Method” was adapted. This article deals with the background behind the variations in soil conditions and the residual uncertainties. The elaboration of the Observational Method is explained, including the measurement results and the decisional system during the construction. Finally the results of the adaption of this method in the project will be evaluated. In May 2014 the building pit was fully excavated, so final conclusions are drawn.
Bilingual Robots: Extracting Robot Program Statements from Swedish Natural Language Instructions
Authors: Stenmark Maj
Published: February 2025

In the English-speaking world, the idea of human-robot interaction in natural language has been well established. The tools for other languages are lacking, more specifically, Scandinavian languages are not supported by robot programming environments. The RobotLab at Lund University has a programming environment with English natural language programming. In this paper a module for Swedish natural language programming is presented. Program statements for force-based assembly tasks for an industrial robot are extracted from unstructured Swedish text. The goal is to create action sequences with motion and force constraints for the robot. The method produces tuples with actions and objects and uses the dependency relations to find nested temporal conditions.
On Associative Confounder Bias
Authors: Wijayatunga Priyantha
Published: February 2025

Conditioning on some set of confounders that causally affect both treatment and outcome variables can be sufficient for eliminating bias introduced by all such confounders when estimating causal effect of the treatment on the outcome from observational data. It is done by including them in propensity score model in so-called potential outcome framework for causal inference whereas in causal graphical modeling framework usual conditioning on them is done. However in the former framework, it is confusing when modeler finds a variable that is noncausally associated with both the treatment and the outcome. Some argue that such variables should also be included in the analysis for removing bias. But others argue that they introduce no bias so they should be excluded and conditioning on them introduces spurious dependence between the treatment and the outcome, thus resulting extra bias in the estimation. We show that there may be errors in both the arguments in different contexts. When such a variable is found neither of the actions may give the correct causal effect estimate. Selecting one action over the other is needed in order to be less wrong. We discuss how to select the better action.
Time-History Modification and Spectral Matching Oriented to Dynamic Geotechnical Analysis
Authors: Ayes Zamudio Juan Carlos  , Flores Lopez Francisco Alonso
Published: February 2025

In day-to-day geotechnical seismic analysis is common practice to generate the seismic forces based on smooth-elastic response spectra, although this perspective has demonstrated full utility, it can present some limitations under some scenarios; nevertheless, to optimize the numerical hypothesis and improve the final design, today is highly recommended the use of empirical Time-Histories (TH) to execute step-to-step analysis that includes the possibility to reproduce the non-linear behavior of soils and structures. Spectral matching procedure is adequate to properly define the seismic-environment of a particular site via TH compatibles with a target response spectrum with the advantage of reducing the employed number of TH; thus, the adjusted TH generation also named synthetic seismogram, born due the necessity to create one or more movements with characteristics (e.g. amplitude, frequency content and duration) similar and consistent with the hazard level of the analyzed site (e.g. design spectrum). In this work, some accessible procedures related to TH pre-processing are explained as well as some parametric analysis oriented to the generation of synthetic TH through the RspMatch program v.2009 [1], finally the paper concludes with critics and general conclusions for its practical application in the geotechnical practice.
Evolución de la respuesta sísmica de una estructura subterránea en la ciudad de México
Authors: Sierra Laura  , Botero Eduardo  , Ossa Alexandra
Published: February 2025

La línea 12 del metro de la ciudad de México atraviesa diversas formaciones geológicas y depósitos de suelos blandos que cambian de propiedades y espesores en distancias cortas. Estos depósitos son afectados por el fenómeno de hundimiento regional, generando un cambio en las propiedades estáticas y dinámicas de los materiales. El objetivo es determinar la variación en la respuesta dinámica de los depósitos de suelo en el tiempo para los casos de estudio de campo libre y considerando a la presencia de la estructura subterránea. Para este análisis se elaboró un modelo tridimensional de diferencias finitas de un tramo subterráneo de la línea 12 del metro, el cual comprende dos estaciones, el túnel intermedio y el depósito de suelo. Para este último se considera la variación longitudinal de los espesores y el alineamiento del túnel. Los resultados muestran que la respuesta sísmica de los depósitos de suelo se modifica en el tiempo por la rigidización de materiales.
Estudo Experimental de Misturas de Solo Arenoso e Cinza de Bagaço de Cana-de-Açúcar e Cinza de Casca de Arroz para Aplicação em Obras Geotécnicas
Authors: Santos S.H.T.  , Casagrande M.D.T.
Published: February 2025

O presente trabalho tem por objetivo o estudo experimental do comportamento de um solo arenoso, reforçado e não reforçado com cinza de bagaço de cana-de-açúcar e com cinza de casca de arroz, por meio da realização de ensaios de caracterização física e química e de ensaios de cisalhamento direto. Busca-se estabelecer padrões de comportamento que possam explicar a influência da adição das cinzas, relacionando-os com os parâmetros de resistência ao cisalhamento e de deformação do solo. Os ensaios foram realizados em amostras com teores que variaram entre 5-20%. Em relação à cinza de bagaço de cana-de-açúcar, a mistura com 10% apresentou melhores resultados nos parâmetros de resistência. Para a utilização da cinza de casca de arroz, pode-se considerar a porcentagem de 20 % como a melhor estudada, uma vez que os parâmetros de resistência apresentados por essas misturas foram quase iguais ou superiores aos do solo puro, com maior porcentagem de resíduo utilizado. Os resultados obtidos neste estudo, em geral, mostraram-se satisfatórios e cumpriram os objetivos iniciais propostos com relação à investigação do comportamento solo-cinza para utilização em obras geotécnicas.
New Model for Improved Rutting Prediction in Unbound Aggregate Layers for Mechanistic-Empirical Pavement Design
Authors: Mishra Debakanta  , Chow Liang Chern  , Tutumluer Erol
Published: February 2025

This paper introduces a new permanent deformation model proposed from a research study recently conducted at the University of Illinois aimed at characterizing the deformation behavior of unbound aggregate materials used in pavement base/subbase applications. Sixteen different aggregate materials, commonly used for base/subbase applications in the state of North Carolina were tested in the laboratory for shear strength and permanent deformation behavior. An analysis framework was established to consider the strong correlation that commonly exists between permanent deformation and shear strength characteristics. Accordingly, the trends of permanent strain accumulations from repeated load triaxial tests were captured in a new rutting model developed by taking into account the shear stresses applied at certain fractions, i.e., 25%, 50% and 75%, of the shear strength properties of these materials under similar loading conditions. Finally, justification has been provided to highlight how this model would present an improvement over the unbound aggregate rutting damage model currently used in AASHTO's mechanistic-empirical pavement design approach. Physical significance of individual model parameters has also been analyzed in this paper, and inferences regarding expected values of these parameters have been drawn. It is concluded that the proposed model has the ability to predict deformation characteristics of aggregate materials by incorporating number of load cycles, shear strength and stress state components.
Behavior of Subgrade Granular Soils under Dinamyc Loads: Permanent and Resilient Deformation
Authors: Cauhape Casaux Marina  , Tadeo María Sol  , Angelone Silvia  , Martínez Fernando
Published: February 2025

The Empirical-Mechanistic Design Method used for the structural design of pavements is based on the determination of stresses at critical points of the structure to establish if the deterioration will remain between some acceptable limits which do not affect the serviceability level offered to the user for the design period. Under traffic loads, soil responds with two different deformations: the resilient or recoverable one and the permanent or plastic one. This work presents a study on the resilient and plastic behavior of unbound granular soils based on laboratory test results carried out using both the repeated load triaxial apparatus and the monotonic triaxial shear strength apparatus. Test results of different types of sand and granular material used as pavement subgrades or subbases are shown; different constitutive models to predict the accumulation of permanent deformation are compared; and finally the evolution of the resilient modulus during the test is analyzed.
Aspectos Geotécnicos de la Torre Única de Comunicaciones
Authors: Capdevila Eduardo  , Flores Roberto  , Barletta Ricardo  , Vasquez Miguel
Published: February 2025

Introducción: IATASA, participó en la elaboración del proyecto de la Torre Única de Comunicaciones (TUC). La TUC es un edificio de gran altura que se prevé ubicar en la localidad de Avellaneda, Provincia de Buenos Aires, la misma albergará un centro de comunicaciones para el Área Metropolitana, contando con antenas, emisoras de radio, televisión digital y sistemas de microondas además de sectores destinados a oficinas, auditorios, museos, gastronomía, etc.
Instrumentação e Monitoramento de um Talude de Solo Arenoso não Saturado no Centro-Oeste Paulista
Authors: Fernandes Mariana Alher  , Augusto Filho Oswaldo
Published: February 2025

A chuva é o principal agente deflagrador natural dos processos de instabilização de taludes de solo em regiões de clima tropical e subtropical. A instalação de diferentes tipos de equipamentos em taludes torna-se uma poderosa ferramenta para compreender e quantificar o processo de distribuição da água da chuva no solo. O objetivo deste trabalho é descrever a instrumentação e apresentar os resultados típicos do monitoramento de um talude de solo arenoso situado próximo ao município de Ribeirão Bonito, Estado de São Paulo, Brasil. A instrumentação deste trabalho é composta por dezoito tensiômetros, dois medidores de nível d´água de máxima e um pluviômetro, os quais foram instalados na crista, na face e na base de duas seções geológico-geotécnica ao longo do talude de solo e monitorados no período de 24 de dezembro de 2013 a 23 de janeiro de 2015. Os valores das leituras dos tensiômetros foram correlacionados com os valores de precipitação pluviométrica, resultando valores de sucção matricial de 3 kPa a 25 kPa no período chuvoso e de 12 kPa a 74 kPa no período seco. Os valores de precipitação pluviométrica medidos a partir do pluviômetro Ville de Paris variaram de 1,0 mm a 57,0 mm em 24 horas, sendo que, o maior valor registrado ocorreu no mês de dezembro de 2013. Para este mesmo período, os medidores de nível d´água de máxima não registraram a ocorrência de nível d´água transiente. De maneira geral, os valores dos tensiômetros mostram que no período chuvoso ocorre menor variação na faixa de sucção enquanto que no período seco, a faixa de valores é maior, independente da profundidade. Estes resultados indicam que a variação de sucção matricial ocorre em função da precipitação pluviométrica, decorrente da alteração no teor de umidade do solo. A inexistência da formação de nível d´água transiente aponta que neste talude predomina a condição não saturada, podendo este ser um grande indicativo que caso haja algum tipo de ruptura, esta poderá ocorrer na condição não saturada.
Suction-Controlled Cyclic Triaxial System for Measurement of Dynamic Properties of Unsaturated Soils
Authors: Suprunenko Ganna  , Ghayoomi Majid
Published: February 2025

Dynamic properties of soils including small-strain and strain-dependent shear modulus and damping are influenced by the degree of saturation and inter-particle suction forces. This change can affect the overall dynamic response of geotechnical systems under earthquake motion. Thus, strain-dependent dynamic material properties including shear modulus and damping play major roles in the seismic response. To this end, accurate estimation of these parameters in various saturation conditions is valuable. This paper focuses on adapting a cyclic triaxial system for dynamic tests with controlled degree of saturation (suction) using axis translation technique. The system development and testing procedure, the preliminary results of suction-controlled, drained cyclic triaxial tests on a fine, uniformly graded sand, and how the changes of suction affect the dynamic properties are presented in this paper. The challenges include controlling and measuring the suction in fast loading during a drained cyclic test and calculating the shear strain and modulus from axial stress-strain hysteresis loops during cyclic triaxial tests. The preliminary data presented in this paper clearly indicates the effect of suction on the shear modulus at a medium strain level.
Uso de Dispositivo Dieléctrico Para Monitoreo de Tefra Volcánica Parcialmente Saturada en Área Metropolitana de San Salvador, El Salvador
Authors: Chavez José Alexander  , Landaverde José  , Mendoza Lesly  , Lopez Reynaldo
Published: February 2025

Para conocer el comportamiento de tefras parcialmente saturadas se ha instalado dispositivo dieléctrico para monitorear taludes, el equipo está basado en principio de transmisión de dominio de tiempo (TDT) para conocer comportamiento de las tefras ante los fenómenos climáticos tales como lluvias y evaporación. Este equipo necesita que se construya una curva de calibración para relacionar los datos de medición electromagnética y contenido de humedad real del suelo. Además mide temperatura a niveles de −10, 0 y +12 cm con relación a superficie de suelo cuando es instalado. Se han obtenido resultados preliminares satisfactorios ya que además se pudieron grabar eventos de movimientos de ladera superficiales durante investigación. Aspectos como la topografía, raíces, costras de suelo biológicas (mezcla compleja de suelo, musgos, algas, liquen, micro-hongos y otras bacterias), granulometría y succión son factores que inciden mucho en comportamiento de taludes. Esta información servirá para uso de suelos, medidas de mitigación, alerta temprana y diseño.
Settlement Monitoring on Camboinhas Experimental Embankment, Rio de Janeiro
Authors: Azevedo Fernando Duarte  , de Sampaio Ferraz Jardim Sayão Alberto  , Sandroni Sandro Salvador
Published: February 2025

Monitoring of embankment settlements using topographic leveling is essential in previewing their evolution and assessing parameters used in designs. Unfortunately, there are few reported cases where settlements were monitored during a long period of time. In this work, settlements of an experimental embankment constructed between the end of 1977 and the beginning of 1978, over a 12m thick soft soils deposit in Camboinhas, Niteroi (RJ), were monitored. At that time, the embankment served as large model to help designing of a commercial housing development. The work was hampered shortly after the end of embankment construction and, since then, no enterprise was held. Settlements were monitored for 200 days between 2014 and 2015, using a procedure that aims to minimize the inherent errors of the leveling process. It was concluded that settlements due to embankment construction were still progressing and are secondary only, due to relatively high coefficient of consolidation obtained by different methods.
Seismic Analysis of a CFRD Dam Using the Material Point Method
Authors: Zabala Francisco  , Oldecop Luciano  , Rodari Rubén
Published: February 2025

Seismic safety of earth or rockfill dams and embankments is strongly conditioned by permanent displacements caused by earthquakes. For a severe earthquake, the permanent displacements pattern results from the combination of displacements generated by volumetric and shear plastic strains distributed within the structure, and those caused by sliding of the soil mass along one or more failure surfaces. Numerical procedures commonly used in practice do not consider the strain localization phenomena at failure surfaces and the associated mesh dependence of the solution. Typically, nonlinear finite element or finite difference codes yield an estimate of distributed deformations and dynamic response, without accounting for the plastic strain localization problem. In addition, some of the numerical approaches used in practice do not consider the change of configuration caused by large displacements. The material point method or MPM is a lagrangian “particle-mesh” numerical method. It has been previously used in modeling dynamic problems with large displacements and strain localization. With MPM, a body is discretized into a collection of lagrangian particles, which carry all the data needed to define the body's state. Interaction between particles takes place in a background fixed mesh, similar to those used in the finite element method. The MPM is applied in this paper to model the dynamic response of Punta Negra dam, a concrete faced gravel dam which is being built in San Juan Province, Argentina. The examples show that the MPM is a useful tool to assess the seismic safety of earth and rockfill structures.
Production, performance and maintenance time observations in mixed soil-rock EPB drives
Authors: González Claudia  , Arroyo Marcos  , Gens Antonio
Published: February 2025

Mechanized excavation in soft rock has been extensively studied in the field of mining when machines such as roadheaders are used. During this time, Tunnel Boring Machines (TBMs) have been the ideal machines for working in hard rock and their application has a good empirical / theoretical basis, especially regarding the excavation efficiency. Both techniques enjoy having such broad empirical support that it lets us establish a good number of benchmarks both to guide the design of the cutting heads and to assess the efficiency of equipment in a given project. In this communication data which has been gathered from more than 33km of tunnels in soil and soil mixed with soft rock that have been drilled through mechanized excavation with EPB is presented. The contrast between the results of these projects, in light of the available recommendations in the literature and other actual cases, let us reflect on the applicability of such recommendations in the case of machines conceived to work in soil or mixed soil and soft rock conditions.
Aplicação de Métodos Probabilísticos na Previsão Espacial de Escorregamentos Deflagrados por Chuvas – Estudo de caso: Pajarito, Medellín, Colômbia
Authors: Botero Eduardo Montoya  , Carvajal Hernán Eduardo Martínez  , Aristizábal Edwin Fabian Garcia
Published: February 2025

No presente trabalho foram aplicados dois métodos probabilísticos, associados a um sistema de informação geográfica, com o intuito de estabelecer a probabilidade de ruptura de escorregamentos deflagrados por uma chuva específica. Foram utilizados os métodos First Order Second Moment (FOSM) e Point Estimate Method (PEM), numa equação de talude infinito, que representa a estabilidade das encostas do local de estudo. A declividade foi obtida a partir do Modelo Digital de Elevação (MDE) das curvas de nível; os parâmetros de resistência foram estabelecidos mediante ensaios laboratoriais e, a poropressão foi calculada usando elementos finitos, com base na ação da chuva. Todos os cálculos são feitos para uma profundidade de 2,5m. Como resultado, além do mapa relacionado a fator de segurança, foi obtido o mapa de probabilidade de ruptura, usando os métodos mencionados.
Application of Soil-Enzyme for Stabilization of Soils in Paving
Authors: Cardoso Malko José Adriano  , Brazetti Rubens  , Casagrande Michéle Dal Toé  , Silva Ben-Hur de Albuquerque e
Published: February 2025

There was in recent years a great offer of patented additives (enzymes) to the road market as solution to soil stabilization. However, they are many times rejected because there are no theoretical foundation to prove such uses, and also because researches themselves don't see research opportunities. Anyway, these products has been marketed, and frequently municipalities and states waste resources by choosing for a solution that is not yet well studied. This study aims to present a methodology to solve the problems that affects the use of additives in laboratory, because his use in conventional tests do not shown efficient for these purposes. For this, it was used a portable traffic simulator, easy handling and common in pavement laboratories. It is a standardized equipment, used to assess the effect of compression and the strain characteristics of asphaltic coating layers. It was developed a set with several accessories to mold samples in the shape of tablets (380 x 50 x 10 mm), may be easily adapted to the equipment selected as simulator. The soils used for the production of the tested tablets were lateritic soils from Rio de Janeiro–RJ, and the enzymatic products were imported. A rigorous care was followed in the production of each tablet to ensure equality and, after, compare results each other. These tablets were molded and tested in order to obtain a series of experimental results, comparing the soil treated with enzymes with the soil without any kind of treatment. The study concludes, in principle, that the equipment used and the developed accessories are appropriate for this purpose and that the use of enzymes showed effective for some applications, but lacks more studies, including with the use of other types of soil to prove such effectiveness.
Natural Disasters Analysis based on IDF Equations
Authors: Kaiser Ilza Machado  , Peixoto Anna Silvia Palcheco  , Pellegrina Geórgia Jorge
Published: February 2025

Several climate models indicate an increase in the occurrence of severe thunderstorms in the Southeast region of Brazil, highlighting the importance of determining vulnerable areas to provide logistical support to agencies that work with victim assistance. A large number of natural disasters were recorded, in Sao Paulo state on the rainy season of 2009/2010 hydrological year. A search was carried out on the IPMET severe events database for significant occurrences triggered by precipitation. A synoptic description of the meteorological condition of the period is presented. The damage related to flooding and mass movements events were spatialized in São Paulo. Moreover, a systematic search for quantitative precipitation data was performed. The probability of occurrence of these events was determined using the usual hydrological resources, IDF equations. The difficulties to associate events with damage occurrence with precipitation threshold are discussed.
Arena de sílice de Ramadillas y su utilización en la explotación no convencional de gas natural (shale gas)
Authors: Poblete F. Mauro  , Salgado R. Karen  , Jeréz Oscar
Published: February 2025

El proceso de extracción de gas en reservorios no convencionales requiere de la utilización de arena de sílice para la fracturación y sostén de la roca en que se encuentra el gas natural. A 70 km al sur de Concepción, cerca de la costa, se encuentran importantes depósitos de arena de sílice con potencial de ser utilizados en el proceso de extracción no convensional de gas natural. Se estudia en detalle la arena de sílice de Ramadillas, analizando su granulometría, esfericidad, redondez, resistencia a la fracturación, conductividad hidráulica, resistencia a la calcinación, morfología y mineralogía. La muestra obtenida en estado natural se divide en diferentes bandas granulométricas optimizando su uso como agente de sostén, maximizando así su resistencia y conductividad. Se determina que la arena de Ramadillas cumple con los requerimientos para ser utilizada en el proceso de fracturación para la extracción no convensional de gas natural, y le permite competir con otras alternativas más costosas como materiales resinados o agentes sintéticos.