bluuebunny/crossref_metadata_2025 huggingface dataset:
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 and Roscoe, 1999) enhancing Terzaghi and Peck's work (Terzaghi and 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.
Identification and Treatment of Erodible Clays in Dikes
Authors: Nagy Gábor  , Nagy László
Published: February 2025

When it comes to flood protection, the established method is to use some impermeable material in water dikes, to prevent seepage. This material is usually some kind of clay soil which is considered as watertight and erosion-resistant. Dispite that, in many occasions not only seepage, but the failure of the dam occured due to tunnel erosion, because these kind of irregular soils are barely investigated, and their presence are not considered during the phase of designing.
Risk Assessment of Induced Earthquake Hazards in the Northern Netherlands
Authors: Peters M.G.J.M.  , Kleinjan J.A.  , Koster A.
Published: February 2025

During the last decade, at least eight earthquakes occurred in the Northern Netherlands with a magnitude of 3 or higher on the Richter scale. These earthquakes are not tectonic but induced by natural gas production from the Groningen Gas Field. Before that time there were no earthquakes in Groningen with such magnitudes. Research conducted by the Ministry of Economic Affairs (EZ) and the State Supervision of Mines (Sodm) showed that both number and magnitude have increased in recent years. The Ministry has given priority to investigate the induced earthquake risks and effects on the most critical structures, installations and infrastructure, such as industrial plants in the Delfzijl – Eemsmond region and public buildings like hospitals and schools. This paper describes a method to develop a risk analysis in order to check the earthquake resistance of structures with the highest risk profile.
Geotechnical Monitoring of a Trial Pit Excavation toward the Boom Clay in Antwerp (Belgium)
Authors: de Nijs Richard  , Kaalberg Frank  , Osselaer Gert  , Couck Jan  , van Royen Kristof
Published: February 2025

In order to relieve the busy traffic arteries of Antwerp (Belgium), the closing of the ring around Antwerp was put to study by BAM (Beheersmaatschappij Antwerpen Mobiel). The design of this construction requires detailed insight in the behaviour of the overconsolidated Boom clay layer during and after dewatering and removal of the covering soil layers. For this purpose a fully monitored excavation test was performed in order to assess the soil behaviour and specific techniques to be used in anticipated projects in the Antwerp area. This paper will specially present and evaluate the results regarding swell and pore pressures recorded in the Boom clay. From the monitoring results it can be derived that the Boom clay shows a quick response to a fluctuation in water level in the overlaying aquifer. The Boom clay also shows a severe pore pressure reduction as a result from loss on effective stress during excavation. These two effects should be considered separately. The underpressure is caused by swell hindered by a very low permeability of the Boom clay. Up to 50% of the effective stress reduction can be transferred into a pore pressure reduction. This condition results in a long term dissipation and swell process towards a gradient of approximately 25 kPa pressure increase per m depth. The pore pressure converges towards the original hydraustatic pressure in the Boom clay.
Concrete Flow in Diaphragm Wall Panels: A Full-Scale In-Situ Test
Authors: van Dalen Jan H.  , Bosch Johan W.  , Broere Wout
Published: February 2025

Flow processes, taking place during the concreting of diaphragm wall panels (D-wall panels), are of great importance for the quality of the wall. During this phase, the bentonite, present in the excavated trench, should be completely replaced by concrete in a controlled way. In literature several cases are described in which this process resulted in bentonite inclusions in the panel. These inclusions often lead to severe problems, like leakages, for the building pit to be excavated within the diaphragm wall panels. Beside the risks for the building pit, leakages caused by bentonite inclusions can also have large consequences for nearby constructions. In this article, set up and results of a full-scale diaphragm wall test are described. Conclusions are drawn with regard to the influence of several parameters on the flow process and subsequently on the quality of the wall and the risk on bentonite inclusions.
Evaluation Settlement Models Test Embankments Bloemendalerpolder – Geo-Impuls Program
Authors: Hoefsloot F.J.M.
Published: February 2025

In the Bloemendalerpolder two test embankments were constructed, starting October 2010, to study the long term behavior of embankments on very soft soils with respect to settlement and lateral pile loading resulting from horizontal soil deformations. A detailed description of the test embankments, performed soil investigation, laboratory tests and instrumentation is given in an accompanying paper. This paper provides a brief description of both test embankments consisting of sand fill with a height of 3.0 m and a plan area 26 × 36 m2with slopes 1:2. At the embankment overlying 5.7 m of clay/peat, wick drains are installed at a triangular spacing of 1.0 m. The second embankment overlying 4.0 m of clay/peat is not provided with any additional drainage accelerating measures. From the laboratory tests settlement parameters were derived for three settlement models; Koppejan-Terzaghi-Buisman, NEN-Bjerrum isotache model and the a,b,c-isotache model. Additionally parameters for Terzaghi and Darcy consolidation models were derived as well: consolidation coefficient, permeability and strain dependent permeability strain factor. Based on applied field loading increments predictions were made. Test results of both embankments will be shown including predictions. Because of the limited dimensions of the test embankments a correction of the monitoring results is applied to match one-dimensional conditions. Based on the measurements a fit of input parameters for all models have been generated matching the settlement of both embankments. Based on these results recommendations are given for application of the models for the site preparation in the Bloemendalerpolder. Researchers, however, are invited to analyse the data to develop more general settlement models for such very soft soils.
Uncertainty Analysis and Risk Management of Underground Cavern Group at Jinping II Hydropower Station
Authors: Zhang Yong-Jie  , Feng Xia-Ting  , Jiang Quan
Published: February 2025

The epistemic uncertainty and aleatory uncertainty caused by the geology condition and construction method make the surrounding rock stability evaluation of underground cavern group difficult. The first may be reduced with more field investigation, tests or monitoring, but the later can not be avoided completely. So the risk analysis method can be used to evaluate the cavern group stability. In this paper, based on the large hydropower underground cavern group database, the risk management stages were divided into two main stages: initial risk management and dynamic and final risk management. For the first stage, the assessment and mitigation methods of overall risk and local risk before the construction of hydropower underground cavern group were suggested. And the dynamic risk was assessed with the fuzzy mathematical method and mitigated during the construction of each layer of cavern according to the revealed geological conditions and actual behaviors of surrounding rock after excavated. Finally, one layer of Jingping II Hydropower Station was analyzed with the proposed method.
Evaluation of Empirical Methods for Estimating Breaching Parameters of Dikes
Authors: Danka Jozsef  , Zhang Limin
Published: February 2025

Dike breaching parameters are important to support dike flood risk management, and can be estimated rapidly using empirical models. Due to the lack of dike specific models, sometimes models for man-made dams were used without validation. This paper compares relevant factors of dike, man-made dam and landslide dam breaches. With the aid of two dike breaching cases, the prediction capabilities of different dike, man-made dam and landslide dam models are studied. It is clearly shown that the models for man-made dams and landslide dams should not be used for dike breaching analysis.
On The Inspection of River Levee Safety in Japan by MLIT
Authors: Honjo Yusuke  , Mori Hirotoshi  , Ishihara Masanori  , Otake Yu
Published: February 2025

The ministry of land, infrastructures, transportation and tourism (MLIT) of the Japanese government maintains governmental managed river levee for the safety against flood whose total length is more than 10,000 km. The design standard of river levee had been traditionally done based on so called shape based specification, where levee is judged to be safe as long as a section satisfies the specified dimensions. In 2002, this policy had been changed and a new inspection guideline which is based on the modern soil mechanics principles had been introduced. The method mainly consists of the non-stationary seepage analysis followed by the circular slip line stability analysis. The exit gradient and uplift pressure are also checked based on specified safety factors. The way of the safety assessment is that, first a river is divided into so called a continuous strip (CS) which is judged to have similar configurations, geotechnical and hydraulic conditions. The typical length of a CS is half to several km long. Then a representative cross section (RCS) that is considered to represent all the CS section is selected. At RCS, detailed soil investigations are carried out, and the inspection is done to assess the safety of the section for stability and piping. A CS is judged to be safe if all the verification items satisfy the specified safety factor, but judged to be NG (no good) if any of the items could not fulfill the threshold value. The first round assessment at year 2011 indicated, only 60% of the all levee is judged to be safe for all verification items. 25% of the levee could not satisfy the stability requirement, 30% piping requirement, and 14% the both requirements. In the paper, the details of the verification methods are described. Furthermore, some recent flood events are introduced. Finally, further challenges for the second screening of the safety of levee are discussed.
Quantifying Statistical Uncertainty in Site Investigation
Authors: Ching Jianye  , Wu Shih-Hsuan  , Phoon Kok-Kwang
Published: February 2025

Due to limited information in site investigation, it is impossible to obtain the actual values for the mean, standard deviation, and scale of fluctuation of a soil property of interest. The deviation between the estimated values and actual values is called the statistical uncertainty. There are two schools of thoughts on how to model the statistical uncertainty: frequentist thought and Bayesian thought. The purpose of this paper is to discuss their philosophical difference, to show how to quantify the statistical uncertainty based on these two very different schools of thoughts, and to compare their performances. For the frequentist thought, the confidence interval will be used to quantify the statistical uncertainty, whereas the posterior probability distribution will be used for the Bayesian thought. Examples will be presented to compare the performances of these two schools of thoughts in terms of their consistencies. The results show that in general the Bayesian thought performs better in terms of consistency. In particular, the Markov chain Monte Carlo method is recommended when the information amount is very limited.
Computing the Reliability of Shallow Foundations with Spatially Distributed Measurements
Authors: Papaioannou Iason  , Straub Daniel
Published: February 2025

In many geotechnical projects, field data is used to determine the soil parameters. In most instances, however, the statistical analysis is performed ad hoc and the spatial distribution of this data is not (expclitly) accounted for. A more formal statistical approach allows to make better use of the data and combine it in a consistent manner with other information on soil parameters. In particular, Bayesian analysis enables combining information from different sources to learn parameters and models of engineering systems, and facilitates a spatial modeling. In this paper, we apply the Bayesian concept to learn the spatial probability distribution of the friction angle of a silty soil using outcomes of direct shear tests at different locations; we then use the derived distribution to compute the reliability of a shallow foundation. We employ two different approaches for constructing the spatial probabilistic model of the friction angle. Both approaches account for the spatial variability of the soil parameter. In the first approach, we apply a single random variable for modelling the soil property within the area of interest. The inherent spatial variability of the parameter is described by the distribution of the random variable and we use the measurements to update the parameter of this distribution. We adopt the simplifying assumption of a highly fluctuating soil and use the distribution of the mean of the friction angle in conjunction with an analytical model for the bearing capacity to update the reliability of the shallow foundation. The second approach consists of modelling the spatial variability explicitly through a random field model and using the measurements to directly update the random field. Thereby, we employ a finite element model of the soil to assess the reliability of shallow foundation.
Learning Music Online
Authors: Loeckx Johan
Published: February 2025

Much of music learning happens outside the classroom in an informal setting, for example online by watching YouTube movies. Despite the many research effort and government projects, many online lack pedagogical foundations while few music educators fully employ online technology yet. In this paper, existing research on online music learning is reviewed as well as platforms and sites that are currently available, mapped in a so-called “market quadrant”. Also, the main problems with the current state-of-the-art are identified, along promising technologies that are believed to address these challenges.
Blended Learning And MOOCs
Authors: Van der Perre Georges
Published: February 2025

The digital transformation of the world is likely to cause dramatic shifts in the world of learning, as is shown spectacularly by the MOOCs phenomenon [5]. It faces universities with the opportunity (and the obligation) to transform themselves thoroughly into institutions with a significantly improved and extended service to society and the ability to adapt flexibly to the rapidly changing needs (learning organizations). The Internet and the multimedia-interactive information technology allow to extend education beyond the (school) hours as well as beyond the (class) walls. The consequences of this simple observation are not yet fully seen. It is not just that universities' own regular full-time students get new “blended” learning schemes offered, but it also means new tools for flexible, part-time and distance learning, and it especially implies that external target groups can be served significantly better, such as future students (study orientation), graduates and professionals (lifelong learning), and last but not least international (global) audiences (virtual mobility).
The Coming of MOOCs
Authors: Steels Luc
Published: February 2025

A MOOC is a Massively Online Open Course. It is massive because there are many students (sometimes hundreds of thousands). It is online because it uses the Internet for course delivery. It is open because it is publically available to anyone without selection barriers or payment. And it is a course, teaching a particular subject, often in engineering and science, but increasingly in all domains of human knowledge including the arts. MOOCs burst on the scene of online distance learning in the fall of 2011 and caused a wave of excitement followed rather quickly by a wave of scepticism and resistance. What are MOOCs? Will they help to deal with the ‘crisis in education’? How do they fit within the earlier developments in distance-education and the use of computers and telecommunication for supporting learning processes? What are the limitations of MOOCs? How can we strengthen them and fully profit from their potential? This paper addresses these questions from my personal viewpoint as an educator involved for decades in teaching and online distance-education. It looks at MOOCs, bringing in a European perspective, and suggests avenues for further research and practice.
Social Flow in Social MOOCs
Authors: Steels Luc
Published: February 2025

Flow theory is a way to explain how humans can be self-motivated and reach a state of high focus and intense, very effective learning. Usually this theory is merely descriptive but recently it has also been operationalized and used as the basis for building autonomous agents. This paper examines how such an operationalization can be incorporated in computer-supported learning environments such as MOOCs. It also expands the notion of flow to take into account ‘social flow’ occurring in a group of learners, such as a sports team or a small Jazz ensemble. We discuss how this kind of social flow can be induced, what the benefits are, and how it is relevant for building learning communities through web and social media.
Chapter 5. Teaching Jazz Improvisation: A Personal Experience
Authors: D'Inverno Ray
Published: February 2025

This short note gives a personal account of how I became an establish Jazz pianist. It emphasizes the importance of personal study and playing in a small group from the very beginning. I also describe various routes to improvisation, which I used as the basis for a MOOC on piano Jazz improvisation, currently in an experimental stage of development.
Chapter 7
Authors: Yee-King Matthew  , Krivenski Maria  , Brenton Harry  , d'Inverno Mark
Published: February 2025

We report on our development of an educational social machine based on the concept that feedback in communities is an effective means to support the development of communities of learning and practice. Key challenges faced by this work are how best to support educational and social interactions, how to deliver personalised tuition, and how to enable effective feedback, all in a way which is potentially scalable to thousands of users. A case study is described involving one to one and group music lessons in an on-campus, face to face, higher education context that were observed and analysed in terms of the actions carried out by the participants. The actions are described and it is shown how they can be formalised into a flowchart which represents the social interactions and activities within a lesson. Through this analysis, specific scenarios emerged where the feedback being given might not be effective, e.g the recipient not understanding the feedback or the provision of feedback which is not specific enough. In answer to these scenarios of ineffective feedback, the requirements for a technological intervention which aims to make the feedback more effective are proposed. With this in mind, we are then able to describe a novel technological platform which has been developed as part of a large-scale European research project and which aims to support effective feedback. The platform is based around focused discussion of time based media, embedded within existing teaching activities at a research led higher education institution in the UK. We outline how it is being used in a blended learning model to support the teaching and learning of music. We reflect on the experience of developing techniques and systems for enabling communities of e-learning and describe our evaluation methodology which involves several case studies and approximately 400 users in its current phase.
Being in an Avatar: Action and Embodiment in a Digital Me
Authors: Triberti Stefano  , Serino Silvia  , Argenton Luca  , Riva Giuseppe
Published: February 2025

This paper provides an empirical research about virtual reality users' avatar embodiment. According to literature, users that are embodied/incarnated in their avatars show a tendency to perceive avatars' failures as their own mistakes. Therefore, they are likely to monitor their own hands on the device they're using (e.g.: keyboard) when they perceive a failure in the interaction (a behavior named “focus shift”). We hypothesize that the phenomenon of focus shift is sensitive to different types of failures that can affect the multiple elements involved in the interaction. Thirty participants guided an avatar through a videogame-like virtual environment. The participants were exposed to three experimental manipulations (defective keyboard, defective avatar, defective virtual environment). We counted the number of focus shifts that participants showed in response to these three manipulated anomalies. Results showed a significantly high number of focus shifts in the condition with defective virtual environment. The findings are discussed with reference to mediation theory, explaining the role of action/feedback matching in the phenomenon of avatar embodiment.
Importance of Virtual Reality to Virtual Reality Exposure Therapy, Study Design of a Randomized Trial
Authors: McLay Robert N.  , Baird Alicia  , Murphy Jennifer  , Deal William  , Tran Lily  , Anson Heather  , Klam Warren  , Johnston Scott
Published: February 2025

Post Traumatic Stress Disorder (PTSD) can be a debilitating problem in service members who have served in Iraq or Afghanistan. Virtual Reality Exposure Therapy (VRET) is one of the few interventions demonstrated in randomized controlled trials to be effective for PTSD in this population. There are theoretical reasons to expect that Virtual Reality (VR) adds to the effectiveness of exposure therapy, but there is also added expense and difficulty in using VR. Described is a trial comparing outcomes from VRET and a control exposure therapy (CET) protocol in service members with PTSD.
Measuring Co-Presence and Social Presence in Virtual Environments – Psychometric Construction of a German Scale for a Fear of Public Speaking Scenario
Authors: Poeschl Sandra  , Doering Nicola
Published: February 2025

Virtual reality exposure therapy (VRET) applications use high levels of fidelity in order to produce high levels of presence and thereby elicit an emotional response for the user (like fear for phobia treatment). State of research shows mixed results for the correlation between anxiety and presence in virtual reality exposure, with differing results depending on specific anxiety disorders. A positive correlation for anxiety and presence for social anxiety disorder is not proven up to now. One reason might be that plausibility of the simulation, namely including key triggers for social anxiety (for example verbal and non-verbal behavior of virtual agents that reflects potentially negative human evaluation) might not be acknowledged in current presence questionnaires. A German scale for measuring co-presence and social presence for virtual reality (VR) fear of public speaking scenarios was developed based on a translation and adaption of existing co-presence and social presence questionnaires. A sample of N = 151 students rated co-presence and social presence after using a fear of public speaking application. Four correlated factors were derived by item- and principle axis factor analysis (Promax rotation), representing the presenter's reaction to virtual agents, the reactions of the virtual agents as perceived by the presenter, impression of interaction possibilities, and (co-)presence of other people in the virtual environment. The scale developed can be used as a starting point for future research and test construction for VR applications with a social context.
Defining Cyberbullying: A Multiple Perspectives Approach
Authors: Alipan Alexandra  , Skues Jason  , Theiler Stephen  , Wise Lisa
Published: February 2025

To date, there has been a lack of consensus among researchers, practitioners, and laypersons about the definition of cyberbullying. Researchers have typically applied the key characteristics of intent to harm, power imbalance, and repetition from the definition of traditional bullying to cyberbullying, but how these characteristics transfer from the real world to a technology-mediated environment remains ambiguous. Moreover, very few studies have specifically investigated how cyberbullying is defined from the perspective of bullies, victims and bystanders. To this end, this article will propose a three-part definition of cyberbullying, which incorporates the perspective of bullies, victims and bystanders.
Interacción Suelo-Estructura en Pilotes Cargados Lateralmente Mediante Elementos de Viga Embebidos en Sólidos
Authors: Turello Diego F.  , Pinto Federico  , Sánchez Pablo J.
Published: February 2025

La modelación del problema de interacción suelo-pilote debido a cargas laterales mediante métodos numéricos requiere la representación de dos subdominios: el suelo y el pilote. Con el objeto de optimizar el proceso de modelación, resulta atractiva la idea de representar el pilote mediante elementos de viga y el suelo mediante elementos de sólidos. En los últimos años se desarrolló el concepto de elementos finitos embebidos, donde los elementos de vigas interactúan directamente con los elementos de sólidos circundantes a través de restricciones cinemáticas que se verifican en la superficie de interacción suelo-pilote. La respuesta mecánica del pilote a carga lateral en el rango de deformaciones laterales moderadas, está influenciada por el comportamiento no lineal del material del suelo en la zona cercana al pilote. Actualmente, uno de los métodos más empleados para estimar la respuesta lateral no lineal del pilote, es el método de las curvas p-y, donde la interacción suelo-pilote se tiene en cuenta a través de resortes no lineales colocados en los nudos del pilote. Las curvas no lineales que caracterizan a estos resortes, que representan la fuerza en función del desplazamiento lateral, fueron calibradas con ensayos a escala real. En este trabajo se propone acoplar una interfaz no lineal a los elementos de vigas embebidos, a fin de tener en cuenta el comportamiento plástico en las proximidades del pilote. Debido a la gran aceptación que tiene el método de las curvas p-y, se propone usar este tipo de curvas para la definición del comportamiento mecánico en la interfaz. Finalmente se ilustra el desempeño numérico del modelo que resulta de acoplar el elemento de viga embebido y la interfaz no lineal en el medio sólido.
Dynamic Response of Vertical Sand Drains in a Zone with Seismic Amplification
Authors: González Acosta José León
Published: February 2025

Preloading is a usual method used to accelerate the process of consolidation of fine-grained soils and increment its bearing capacity. To improve this technique, vertical sand drains with a given diameter and between one or two permeable strata are placed under an embankment which is intended to increase pore pressure and induce the process of consolidation. Countless research concerning the effectiveness of vertical sand drains has been made, but its capability to hold stable without suffering considerable damage, which may affect its performance, during and after a seismic event is an issue that remains unknown. This paper shows an analysis concerning the dynamic response of vertical sand drains during an earthquake. First, a free field dynamic analysis using data of an earthquakes occurred in Mexico City in a zone composed by highly compressive clays capable of increasing the dynamic response of the soils will be carry out. Then, the change in the response in the surface will be obtained considering the sand drains in the model and considering the sand drains along with the embankment. Also, the performance of the drains (deformations) during the maximum response of the soil will be obtained. The analysis will be performed by means of the Finite Element Method (FEM) using MIDAS GTS NX software, including additionally an extensive explanation about the basis taken into account to create the model (soil static and dynamic properties, boundary conditions, etc.). Finally, conclusions about the results will be made including remarks about the model creation.
Evaluación de propiedades físicas e hidráulicas de los suelos derivados de cenizas volcánicas de la región de Popayán, Colombia
Authors: Hernández O.  , Cordão Neto M.P.  , Caicedo B.
Published: February 2025

Según Lizcano & Herrera (2006) los suelos derivados de cenizas volcánicas representan aproximadamente el 11.6% de los suelos en Colombia y están localizados en las principales zonas de crecimiento demográfico y económico del país. Este suelo es predominante en la región de Popayán en Colombia, donde existen muchos problemas con la compactación, erosión y estabilidad de los taludes, motivo por el cual se necesita conocer el comportamiento hidromecánico de este suelo para su mejor utilización en obras de ingeniería.
Estudo Comparativo da Evaporação de Solos não Saturados Através de Métodos Empíricos em duas regiões da frança
Authors: Araújo Larissa C.  , Bicalho Kátia V.  , Dantas Bruno T.
Published: February 2025

Neste trabalho avalia-se de forma comparativa a influência da interação solo-atmosfera na evaporação de um subsolo não saturado em duas regiões da França, com condições climáticas distintas. São utilizadas cinco equações empíricas (Thornthwaite, 1948; Turc, 1961; Romanenko 1961; Blaney e Criddle 1959; e Kharrufa, 1985) para o cálculo da evaporação potencial ET em duas regiões com condições climáticas distintas localizadas na França. Os métodos empíricos selecionados são baseados, principalmente, em dados climáticos de fácil medição, tais como: temperatura do ar, umidade relativa do ar, porcentagem de horas luz e radiação solar. O Balanço Hídrico Atmosférico (BHA) de cada uma das regiões estudadas, em um determinado período, é também avaliado. Os métodos empíricos publicados para determinar ET baseados em dados climáticos regionais apresentam grandes diferenças mensais (mais que 100 mm/mês) e anuais (até cerca de 1000 mm/mês), e, portanto devem ser usados somente para estimativas preliminares do BHA.
Sobre el Comportamiento de los Suelos Potencialmente Activos Estabilizados para su Uso en la Ingeniería Vial
Authors: Cosentino José M.  , Rico Oscar  , García Alejandro  , del Río Guillermo  , Medina Ma. Emilia  , Cotorruelo Ezequiel  , Cristaldo Sebastián  , Romero Alejandro  , Waldbillig Juan Esteban
Published: February 2025

Los movimientos generados por los fenómenos de expansión retracción del suelo y los estados tensionales agresivos para las estructuras viales, en general se intentan controlar con la incorporación de sustancias que puedan combinarse químicamente con el terreno existente y eliminar la actividad del material arcilloso. Con éste trabajo se propuso ampliar el grado de conocimiento en el tema de los suelos de la región noreste de la provincia de Entre Ríos. Se planteó la necesidad de ponderar cualitativa y cuantitativamente los aditivos a incorporar vinculando esa “dosificación” con las propiedades índice de estos suelos. Con muestras de suelo de dos localidades, ejecutando ensayos de laboratorio en situaciones controladas, se obtuvieron curvas de tendencia que permitieron relacionar porcentajes de “hinchamiento” y “valor soporte relativo”, con cantidades crecientes de adiciones para distintas condiciones iniciales de densificación.
Levee stability and the interaction between a stiff embankment and a very soft subsoil
Authors: Zwanenburg C.  , Teunissen J.A.M.  , de Lange D.A.  , Van M.A.
Published: February 2025

Levee stability is influenced by the subsoil on which the levee is founded. Not only subsoil strength also the subsoil stiffness plays a role. This paper discusses a series of centrifuge tests and its analysis, in which the influence of foundation stiffness is studied. Both centrifuge tests and numerical analysis show that by increasing foundation stiffness a reduction of the failure load is found. This effect is explained by geometrical effects. In numerical analysis a large strain approach is essential in reproducing the geometrical effects. The tests show an influence of the pre-consolidation pressure of the Speswhite clay and presumably the saturation ratio. This last aspect has not been studied.
Análisis de las Propiedades Físicas, Mecánicas y Micro-Estructurales de un Limo Arcilloso para ser Empleado en la Construcción de Presas de Tierra
Authors: Buriticá García Julián  , Pacheco de Assis André
Published: February 2025

Los materiales disponibles y las características topográficas Brasileras han llevado casi siempre a que se elijan presas de tierra y enrocado para generar energía eléctrica. Sin embargo existen regiones lluviosas con elevadas precipitaciones anuales donde se hace difícil la construcción de este tipo de presas. En esos lugares donde la humedad del suelo es mayor que la humedad óptima, se acostumbra tratar el suelo con adición de cal o escarificarlo para reducir el contenido de agua del suelo, pero esta práctica generalmente ocasiona atrasos en las construcciones de este tipo de obras. Este contexto motivó la realización de esta investigación. En este trabajo son presentados los resultados de los ensayos de laboratorio de caracterización física, compactación, compresión edométrica, permeabilidad, ensayos triaxiales saturados tipo CD y microscopia electrónica de barrido, realizados en cuerpos de prueba compactados por medio de la metodología proctor normal, en la humedad óptima, la humedad óptima + 2% y en la humedad óptima + 5% de una muestra de un material limo arcilloso, colectado en la ciudad de Brasilia, Distrito Federal. Se presenta el análisis de las propiedades físicas, mecánicas y micro-estructurales del material para ser empleado en la construcción de presas homogéneas y heterogéneas con núcleo impermeable en regiones tropicales con elevadas precipitaciones.
Diseño de sistema de estabilización de una excavación circular de 80 m de diámetro y 42 m de profundidad, en rellenos heterogéneos y tobas, en Ciudad de México
Authors: Cirion Arana Alfredo  , Paulín Aguirre Juan
Published: February 2025

Este trabajo trata el análisis y diseño del sistema de estabilización para una excavación a máximo 42 m de profundidad en un sitio localizado al poniente de la ciudad de México. Se describen las condiciones geotécnicas del sitio, destacando la presencia de un potente estrato de suelo re-depositado (rellenos heterogéneos predominantemente granulares muy sueltos), los cuales sobre yacen a los depósitos vulcano-sedimentarios propios de la región. Se presentan también las hipótesis de diseño y la solución para la estabilización de la excavación, la cual consiste en la formación de un pozo circular de gran diámetro (80m) formado por un muro de concreto lanzado como elemento estructural definitivo, construido secuencialmente formando anillos de forma descendente. En la zona de rellenos inestables se considera la construcción de una pantalla perimetral (previo a la excavación) formada por pilas de concreto simple contiguas entre sí para garantizar la estabilidad local y con ello evitar la generación de fallas generales en la excavación.
Análise Espacial da Estabilidade de Encostas Visando a Implantação de Vias com o Uso do Shalstab – Aplicação em Sub-Bacias do Rio Tubarão
Authors: Michel Gean Paulo  , Mafra Vicente  , Contessi Rodolfo Joaquim  , Higashi Rafael Augusto Dos Reis
Published: February 2025

Urban dynamics is called as the process of use and occupation of urban center, which can be diagnosed based on the expansion of the road system. This dynamic is subject to factors of various kinds, including geotechnical factor, which can be associated with the slope stability. Thus, this research has made a spatial analysis integrating the instability of the slopes and the implementation of the resulting road system of the expansion of the urban center of Tubarão, located in the state of Santa Catarina.O Shark city was chosen as the site of application of this methodology by geomechanical have characteristics similar to other coastal cities in the state of Santa Catarina, which allows the extrapolation of this technique to other municipalities. For this analysis we used the SHALSTAB software (ShallowSlopeStabilityModel), which connects hydrological data, discretized into bowls, and soil strength parameters for obtaining a map landslide susceptibility rasos.Como conclusion of this study, there was a concentrated growth the road network in regions of low quotas the median, not being occupied critical areas of steeper slope. Moreover, with respect to stability analyzes, which were divided into drainage units, it has been observed that although unit River considered to be the most stable for this study, as compared with the other studied areas, the land use of the basin is not intense. This fact points to the need for readjustment of the use and occupation of land in the urban center Shark, encouraging the mechanical stress of the most stable areas and restricting the occupation of areas more susceptible to landslides.
Deep Characterization of the Santiago Basin for Seismic Site-Response Evaluation using Seismic Noise Cross-Correlation
Authors: Pastén César  , Saez Miguel  , Leyton Felipe  , Ruiz Sergio
Published: February 2025

We deployed a temporal network of 24 broadband stations that continuously measured seismic ambient noise in order to investigate the intermediate and deep structure of the Santiago basin for seismic site-response evaluation. Empirical Green's Functions (EGFs) for selected pairs of stations at different frequency bands were obtained from time-domain cross-correlation of the extended seismic noise records. The EGFs were used to estimate phase velocity dispersion curves and shear wave velocity profiles. The resolution of the method allows solving intermediate depths associated to periods from 0.25 to 2 s, a critical period range for infrastructure. The results show average shear wave velocities between 1,250 to 1,450 m/s for depths larger than 150 m and velocities around 800 m/s for gravelly soil deposits of the central area that are consistent with single-station H/V spectral ratio results.
Elaboração do Mapa Geotécnico Preliminar e Análise das Áreas Suscetíveis a Deslizamentos Rasos do Município de Antônio Carlos, SC
Authors: Guesser Luiz Henrique  , Higashi Rafael Augusto dos Reis
Published: February 2025

A frequência e intensidade dos desastres naturais vêm aumentando em consequência das mudanças climáticas que ocorreram no planeta e, principalmente, pela ação antrópica desordenada. Com isso, os danos socioeconômicos e ambientais também sofreram significativo aumento. O mesmo ocorre no Brasil, sendo que os deslizamentos de encostas são considerados um dos desastres naturais mais frequentes no país. Este trabalho se propõe a elaborar o mapa preliminar das unidades geotécnicas do município de Antônio Carlos/SC e o mapa de suscetibilidade a deslizamentos rasos do município, ferramentas estas necessárias para auxiliar no gerenciamento, uso e ocupação do solo. Os mapas necessários para elaboração deste trabalho foram adquiridos junto à Prefeitura Municipal de Antônio Carlos, Secretaria de Estado do Desenvolvimento Sustentável de Santa Catarina, Departamento de Geociências da Universidade Federal de Santa Catarina e ao Instituto Brasileiro de Geografia e Estatística. O mapa geotécnico preliminar foi elaborado segundo a metodologia proposta por Regina Davison Dias. Gerou-se o mapa de suscetibilidade a deslizamentos rasos para diferentes cenários, conforme o modelo SHALSTAB. Como resultados, foram obtidos o mapa geotécnico preliminar de Antônio Carlos, composto por oito unidades geotécnicas e o mapa das áreas suscetíveis a deslizamentos rasos, gerado para diferentes cenários, com profundidades de ruptura variáveis.
Non-destructive control methodology for micropiles based on low strain dynamic load test
Authors: Calvente R. Matías  , Breul Pierre  , Benz Miguel Angel  , Gourves Roland  , Bacconnet Claude  , Gotteland Philippe
Published: February 2025

Micropiles are widely used since their creation in the 1950s in Italy by Dr. F. Lizzy [1]. This foundation technique has been highly developed; nevertheless, such growth does not come with a development of specific “proof” load tests. Actually, among the control techniques that can be used in micropiles, the uplift load test is the most widely used. The static load test is easy to perform and interpret, however this test cannot be made systematized. In this paper a methodology to control the ability of the micropile to safely carry the design load in service based on a simple low strain dynamic load test (LSDT) is developed and adapted to the specific conditions of the site. LSDT test consist in the application of a simple low energy impact that allows determine the small-strain elastic stiffness of the micropile-soil system. The objective is to test in a relatively simple, economical and systematic way vertical micropiles. The calibration and for subsequent validation of the testing method and its protocol have been carried out from a large amount of static and dynamic test performed on 18 real scale micropiles made in an experimental site. The results show that the proposed methodology allows determining the micropile bearing capacity under service loads. This methodology is easy to carry out and has an immediate interpretation; also it is particularly adapted to the reals conditions of micropiles site constructions.
Development and applications of a portable erosion test device
Authors: Anwar Tariqul  , Huang Jie  , Johnson Drew W.
Published: February 2025

Vegetation is an effective way to mitigate soil erosion; however, there is no portable device available to assess the erosion around a single plant. This study focused on developing a portable erosion device to assess erosion around a single plant in the field, which can also be used to assess cylindrical soil specimens. The device mainly consists of a speed-controlled agitator, a plat blade paddle, and a thin wall tube. The thin wall tube holds the water in which the paddle, connected to the agitator, will generate a vortex to mimic the flow around a plant. The applicability of the device was examined by a series of comparison tests and a shear stress analysis. For the comparison tests, the device was used to assess the erosion of the soil specimens and the soil specimens with a single plant root under different paddle revolution rates. The erosion was monitored for hours until the erosion rate became steady. The total amount of eroded soil was plotted as a function of time. Data indicated that the paddle revolution rate needed to exceed a threshold value to achieve consistent measurements. When the paddle revolution rate was less than the threshold value, the test showed poor repeatability due to the deviation in the surface texture among the soil specimens. The shear stress induced by the vortex was derived based on the paddle revolution rates, water viscosity and location of the paddle. It was found the erodibility of the tested soil, as a function of shear stress, was consistent with published data.
Contenções com Paredes Diafragmas Análise Crítica de Métodos de Cálculo
Authors: Küpper Fernanda A.G.  , Massad Faiçal
Published: February 2025

O cenário de escavações urbanas profundas em solos aluvionares e com presença de elevado nível d'água aponta a parede diafragma como principal solução estrutural para projetos de contenção de terra. As informações obtidas através de investigações geotécnicas são fundamentais para a elaboração de projetos seguros e econômicos, considerando a natureza dos carregamentos atuantes, as características do solo e suas propriedades. O ensaio tradicionalmente utilizado no Brasil é o Standard Penetration Test (SPT), porém, recentemente, tem-se buscado executar modernos ensaios in situ para determinação de parâmetros geotécnicos da Bacia Sedimentar de São Paulo: Ensaio Dilatométrico (DMT), Ensaio Piezométrico (CPTU) e Ensaio Pressiométrico (PMT – Camkometer). O problema é analisado considerando não somente as estimativas de parâmetros dos solos dos diversos ensaios in situ como também o processo evolutivo da construção. O presente estudo visou analisar: (i) os métodos usuais de cálculo para dimensionamento das contenções do tipo parede diafragma; e (ii) confrontá-los com métodos numéricos com parâmetros geotécnicos obtidos através de ensaios in situ como o Pressiômetro e o Dilatômetro Marchetti (DMT).
Geotechnical behaviour of unpaved roads: understanding the CBR test
Authors: Caicedo Bernardo  , Mendoza Cristhian
Published: February 2025

Unpaved roads constitutes a significant portion of road networks in developing countries. These roads are constructed by a succession of layers of unbound granular materials having different characteristics. From the geotechnical point of view, unpaved roads involve numerous complexities in their behavior such as: repetitive loads producing accumulation of plastic strains, stress rotation, abrasion and crushing; and all that occurs in unsaturated soils having strong interaction with the environmental conditions. The principles of current applied to unpaved roads are based on the results of the California Bearing Ratio tests (CBR). However this test is more related with the strength characteristics of the material (friction angle and apparent cohesion) than its stiffness (young modulus and Poisson ratio). This paper presents the influence of the intrinsic variability of soil parameters in the California Bearing Ratio tests by means of numerical simulations. These simulations were performed to penetrate a soil sample with a plunger of standard area using a random finite element method, in terms of soil parameters. The results of the CBR test are discussed.