bluuebunny/crossref_metadata_2025 huggingface dataset:
A Supporting Model for the Dynamic Formation of Supplier Networks
Authors: Teixeira Kellyn Crhis  , Borsato Milton
Published: February 2025

Supply chains have become an important focus for competitive advantage. The performance of a company increasingly depends on its ability to maintain effective and efficient relationships with its suppliers and customers. The extended enterprise (i.e. composed of several partners) needs to be dynamically formed in order to be agile and adaptable. According to the Digital Manufacturing paradigm, companies have to be able to quickly share and disseminate information regarding planning, designing and manufacturing of products. Additionally, they must be responsive to all technical and business determinants, as well as be assessed and certified for guaranteed performance. The current research intends to present a solution for the dynamic composition of the extended enterprise, formed to take advantage of market opportunities quickly and efficiently. A protocol model has been elaborated and inspired in the OSI reference model with reference to the Supply Chain Operations Reference model (SCOR®). This model provides a framework for linking customers and suppliers. It is presented in the form of seven layers that relate to steps for negotiating the participation of candidate companies in the dynamic establishment of a network for responding to a given demand for developing and manufacturing products, as follows: request for information; request for qualification; alignment of strategy; request for proposal; request for quotation; compatibility of process; and compatibility of system. An information model has been defined based on the concepts of SCOR® as well. The protocol model has been implemented by means of process modeling according to the BPMN standard and, in turn, implemented as a web-based application that runs the process through its several steps, which uses forms to gather data. An application example in the context of the oil and gas industry is used for demonstrating the solution concept.
Data Flow To Manufacturing Simultaneous With Design Phase
Authors: Ilter Dilşad  , Şenaltun Gülden  , Cangelir Can
Published: February 2025

Designing and producing an item with the best quality is a common concern for companies. Decreasing time consumed design and production stages is a new concern with the accelerating world views. Design or production phases cannot be accelerated in order not to concede the quality. So as to, managing both design and production related stages in parallel can be an option to reduce the time consumed. Concurrent engineering philosophy suggests different ways to achieve this goal. In traditional approach, production and production related stages' planning (NC programming, tool design, raw material procurement) starts after design phase is completed. This approach causes time loss. As wells as, project management struggles shortening the project schedule. At this point, concurrent engineering offers a solution that enables procurement of raw materials and making production arrangements (NC programming, tool design, manufacturing planning) in accordance with data flow from design while project is still in design phase. Tight project schedule can be relieved in two ways with this concurrent engineering approach. First is backdating production arrangements and ordering raw materials earlier while project is still in design phase. Second proposal provides taking preventive actions by discovering prospective design related problems. In this paper, management of data flow from design department to manufacturing department will be studied. In order to get the best outcomes, management of data flow with a PDM (Product Data Management) tool will be clearly stated in requirements, restrictions, type and planning of data perspectives. In addition to these topics, management of changes in data shared to manufacturing planning department will be studied. As well, all topics studied in this paper will be supported with an industry implementation.
Impact of Non-Functional Requirements on the Products Lines Lifecycle
Authors: Urrego-Giraldo German  , Giraldo Gloria  , Delgado Myriam
Published: February 2025

The big progresses in Information and Communication Technologies and the increasing development of web systems highlight the importance of Non-Functional Requirements (NFR) in the construction of knowledge and information systems. This kind of requirements has been always present, indicating the systems quality. But, the traditional supplementary role of implicit expected quality attributes changes in an explicit central role in specialized technological solutions centered on massive interactions of agents who access communications nets at anytime, anywhere, with any means. The dynamicity of the collective work, of the diversification, integration, and deepening of knowledge treatment of every intervention field in the society, as well as the massive interaction of persons, machines, and objects support the emergence of new products development approaches and their lifecycles. For example, in Software Products Lines, the changes in the lifecycle determine that the Non-Functional Requirements must be defined in earlier phases than in the software lifecycle. In this paper it will be explained why and what is the meaning of the introduction of Non-Functional Requirements in earliest phases of Products Lines lifecycle. Highlight the changes of Non-Functional Requirements introduced in phases of product lines lifecycle and their impact in every development phase is the goal of this article.
Generic Functional Decomposition of an Integrated Jet Engine Mechanical Sub System Using a Configurable Component Approach
Authors: Raja Visakha  , Isaksson Ola
Published: February 2025

A procedure is proposed to functionally decompose an already existing integrated mechanical jet engine subsystem. An integrated sub system is a system where the same design object satisfies multiple functions: which is typically the case in aircraft engine sub systems and components. A generic decomposition method will allow implementation and use in automated design systems and will function as a means to build experiences into platforms. Using the procedure, an enhanced function-means tree (E F-M tree) consisting of functional requirements, means to satisfy the requirements and constraints was created for the integrated jet engine component. The E F-M tree is then used to generate a hierarchy of configurable components (CCs). A configurable component (CC) is a stand-alone conceptual object that contains the functional requirement, means to satisfy the requirement (or design solution) and constraints at a certain level of the E F-M tree. A specific CC hierarchy configuration results in the description of the product concerned. The usage of the CC hierarchy as design documentation as well as a template to derive other designs from is demonstrated. Finally limitations of describing product functional requirements using CC method and recommendations for further development of the method are discussed.
Design Optimization of Electric Propulsion of Flying Exploratory Autonomous Robot
Authors: Wąsik Mateusz  , Skarka Wojciech
Published: February 2025

The main idea of the paper is to optimise the design parameters of the electric propulsion of exploratory autonomous robot designed for flying in specified extremely unfavourable environment. There are still a lot of unsolved needs in the flying autonomous robots area. A lack of solutions for drones flying in the unpredictable and turbulent conditions has been identified. As examples of such needs the following could be distinguished: exploration of the space-planets with their own atmosphere different from Earths or on Earth drones being used in mountain and marine emergency services which operate in extremely unfavourable weather conditions. The main issue from the propulsion designs site is the influence of the turbulent wind, sometimes connected with precipitation on the flight mechanics. As another important concern the strength of the propulsion of the flying object can be mentioned. Another aspect which has a profound effect on the operation of such a robot drive is the best energy balance of such devices and the desire to ensure its long-term operation and extreme maximum performance. Already, each of these tasks is solved separately and optimization is a major challenge. However, the multi-criteria optimization taking into account the coupling phenomena occurring on the robot is a much bigger problem. In the paper the requirements for the propulsion are presented and the concept solutions for specified unfavourable environments is proposed. The very definition of the assumptions of the environmental conditions defining the tasks of optimizing the yarn can be a problem. Excessively harsh conditions lead to the solutions unacceptable in practice. The following features of the conceptual drones propulsion design are analysed: aerodynamics, strength, stiffness, mass and mobility. Consequently, the analyses lead to the optimization of the shape and design of the drones propulsion system.
Towards a Proposed Process to Manage Assumptions during the In-Service Phase of the Product Lifecycle
Authors: Iley John  , Bil Cees
Published: February 2025

Assumptions affect our everyday life and more specifically in business they can have a profound effect on an organisation's support services delivery performance if they prove to be wrong. The literature shows the need to identify assumptions and expose any implicit assumptions that may have a major impact on the business objectives. There are also examples of methodologies that suggest there are advantages in managing assumptions for strategic decision making. However, there is little research dealing with the ongoing assessment or review of assumptions when delivering support services during the In-Service phase of a product's lifecycle. The outputs of various government audit reports and independent enquiries suggest that erroneous assumptions are a potential cause of death or serious injury and substantial increases in costs or reductions in capability of major capital systems. This suggests that a method for the ongoing review and management of assumptions would be beneficial as an aid to the successful delivery of support services. An industry project was observed to gain an insight into how projects deal with assumptions. A number of methods from the strategic planning, risk management and reliability engineering domains are compared and these form the basis for a proposed process to manage assumptions in the In-service phase of a system's lifecycle.
Studies of Air Transport Management Issues for the Airport and Region
Authors: Zhong Z.W.  , Tee Y.Y.  , Lin Y.J.
Published: February 2025

We analysed the effects of increasing low-cost carrier flights on the airport runway capacity. Different runway utilisation approaches were simulated to study their pros and cons. The single arrival and departure runway approach gives the best results for runway capacity and safety measures. The approach can be applied to runway 3. It can be allocated for only arrival or departure flights during certain time slots to cope with the ever increasing growth of flight movements in the region. We also examined the flight delays in December 2013. An ANOVA and a t-test were performed with two sets of the delays to find that thunderstorms would significantly affect the duration of the flight delays. The delays were translated into the number of flights loss due to deficiency caused by thunderstorms. The number was then used in a derived equation to compute the profit loss due to the thunderstorms in 2013. A simulation and modelling function has been established by the ATMRI to conduct analyses of airspace structures and traffic flows throughout the region.
Service-oriented Life Cycles for Developing Transdisciplinary Engineering Systems
Authors: Sobolewski Michael  , Kolonay Raymond
Published: February 2025

A transdisciplinary computational model requires extensive computational resources to study the behavior of complex engineering systems by computer simulation. The large system under study that consists of hundreds or thousands of variables is often a complex engineering design system for which simple, intuitive analytical solutions are not readily available. In this paper the basic concepts of mogramming (modeling and programming, or both) for N3(three-dimensional design structure matrix) diagramming in a Service-ORriented Computing enviRonment (SORCER) are presented. On the one hand, mogramming with service variables allows for computational fidelity with multiple services, evaluations, and sources of data. On the other hand, any combination of local and remote services in the system can be described as a collaborative service federation of engineering applications, tools, and utilities. A service-oriented lifecycle for all phases of mogram-based systems development reflecting N3diagraming is presented. In particular all basic phases from inception through analysis, design, construction, transition, and maintenance are outlined in a service-oriented framework for deploying transdisciplinary engineering design systems.
Customer Engagement in Product Development: Bring UX Upstream
Authors: Fukuda Shuichi
Published: February 2025

Early version CE focused on efficiency of product development. Then with the diversification of customer requirements, it changed to collaborative engineering and the emphasis was placed on how experts from different fields can work together as a team to come up with a solution to respond to the diversifying requirements. But these versions are primarily producer-centric and customers are considered to be end-users or passive consumers. But if we note CE is the tool to integrate all processes, we will be aware that we forgot about the last process of usage. If we can get customers involved in design and manufacturing, we can create experience for our users beyond UX and customers can enjoy being a player in the game. Their needs for self-actualization will be satisfied and they will be most happy. To achieve this, reconfigurable modularization is expected to provide a versatile tool for design And manufacturing and it will not only turn design and manufacturing to value creating processes, but it also may enable us to grow our product value for the lifetime. This can be realized because this new approach pays attention to the fact not only products, but processes also generate values.
Improving the Ability of Future Engineers by Using Advanced Interactive 3D Techniques in Education
Authors: Skarka Wojciech  , Wyleżoł Marek  , Januszka Marcin  , Rzydzik Sebastian  , Targosz Miroslaw
Published: February 2025

For technical field a lot of issues which are necessary to understand the subject is adjustable in the sphere of abstraction. For people, who do not have adequate knowledge, imagining even a simple element/assembly based on its orthogonal projections is not a significant problem. Such problems are well known and are the main goal of our research. The objectives of the project InterEdu was mainly to increase the quality of education. The ability to apply the techniques of passive and active 3D is assumed by default for the future engineer applying concurrent engineering methods. Aiding the teaching process with the use of a system which allows presentations of knowledge and data in a 3D virtual reality environment should result in a more efficient way to browse, evaluate, interpret and hence better understand the presented contents. The application of these techniques in a variety of courses not only makes it easy to explore the content of these courses but also allows students to become familiar with the use of sophisticated data visualization and to cooperate in various fields. The aim of the validation studies was to evaluate the operation and usefulness of the system in the context of its use in order to facilitate learning. The evaluation has been subjected to issues how the visualization of knowledge influences the effectiveness of the process of teaching. The students, taking part in the evaluation process, indicated the usefulness of this system in the teaching process. The InterEdu system improves the process of education and effectively aids the students who have difficulties in the content interpretation, especially at the earlier years of study.
Product Avatar as Digital Counterpart of a Physical Individual Product: Literature Review and Implications in an Aircraft
Authors: Ríos José  , Hernández Juan Carlos  , Oliva Manuel  , Mas Fernando
Published: February 2025

‘Product Avatar’ and ‘Product Digital Twin’ are the terms used currently to refer to the product digital counterpart of a physical product. Both terms derived from different perspectives and from different initial objectives. With a specific focus on the aerospace sector, this communication is a starting point and reviews the different topics involved in the creation of an aircraft digital counterpart, i.e. product identification, product lifecycle, product information, product configuration, product models, and software applications involved. Then, a specific section presents both approaches, ‘product avatar’ and ‘product digital twin’, together with the currently published related works. The paper ends with a discussion of the implications of creating an aircraft avatar with an industrialization-oriented perspective.
The Improved Global Supply Chain Material Management Process Framework for One-Stop Logistic Services
Authors: Hsu Abby P.T.  , Chang Ai-Che  , Trappey Amy J.C.  , Trappey Charles V.  , Lee W.T.
Published: February 2025

This research focuses on the material procurement process improvement of a manufacturer under one-stop logistic services and proposes a to-be process offering a vendor-managed inventory (VMI) and information integration services provided by one-stop logistic services providers (1SLP) for shortening the procurement and manufacturing lead time, and enhancing the information flow accuracy and transparency. The 1SLP is an integrator that assembles the resources, capabilities, and technologies of supply chain networks to design and implement comprehensive logistic solutions. The research develops the 1SLP process framework by dividing the service scope into four service models. We use a case example to demonstrate the improved process. The case company is a leading manufacturer in producing projectors for the global market. The current material procurement process causes long lead times, delays the manufacturing process, and does not integrate all information in the supply chain. In the to-be model, a 1SLP incorporated model 2 services and provides a VMI warehouse as a value-added service and integrated information platform to ensure the buyer's inventory level and implements appropriate logistics optimization for efficient delivery. The AnyLogic Simulation Software is used to model the current and the to-be business processes. The comparison between the as-is and the to-be models demonstrates that the improved material procurement process increases the current process's efficiency under the one-stop services without impeding product availability to the target market.
4.3. Vehicle Terrain Mobility Enhancement and Minimization of Energy Consumption
Authors: Vantsevich Vladimir V.  , Gray Jeremy P.
Published: February 2025

A new method to improve vehicle mobility and energy efficiency of multi-wheel vehicles is proposed. It is shown the power distribution between the drive wheels impacts driveline power losses and power losses in the tire-soil contacts. Conditions for the maximum driveline efficiency analysed and the maximization of the tire slippage efficiency are analysed for a 6x6 terrain vehicle with different driveline configurations.
10.1. The Role of the Suspension System
Authors: Blundell Mike  , Dickison Mike
Published: February 2025

This Section covers the role of the suspension system for vehicle ride and handling and the design process involved with suspension systems to ensure good performance. The durability of the suspension system due to operating in aggressive environments and resilience to abuse loads is also discussed.
Medical Response to Lone Actor Incidents
Authors: Mechem C. Crawford
Published: February 2025

The number of lone actor terrorist attacks has increased in recent years. These have taken the form of bombings, shootings, stabbings, the deployment of chemical or biological agents, and the use of vehicles as a weapon. The medical response to such attacks primarily involves patient care once the incident is over. However, in the case of lone actor attacks that take the form of an active shooting, a modified response by Emergency Medical Services (EMS) providers may allow for treatment of some victims before the scene is fully secured. Two recent active shooter incidents in Pennsylvania, the West Nickel Mines Amish school shooting and the Kraft Foods plant shooting in Philadelphia, are presented with a description of medical issues encountered. The Rapid Assessment Medical Support (RAMS) program, developed by the Philadelphia Fire Department and the Philadelphia Police Department based on lessons learned from these and other such incidents, is one way that EMS providers can initiate patient care at active shooter incidents in areas that have been cleared by police but not secured. It is based on the premise that care of victims is a shared responsibility of police and EMS. It involves close coordination and ongoing training between the two departments with a priority given to early hemorrhage control, airway management, patient evacuation away from the immediate threat, and rapid transport to a trauma center. The RAMS program represents one way to potentially save lives during lone actor attacks.
Legal Responses to Lone Wolf Terrorism
Authors: Vesely Michael
Published: February 2025

This note serves as an introduction to the American legal system's attempts to deal with lone wolf terrorism. It outlines the general approach that courts employ in legal proceedings, with particular emphasis given to terrorism cases. The note also provides an overview of key antiterrorism laws and their applicability to lone wolf terrorists, including enhanced governmental tactics and emerging technologies. This paper concludes by considering various proposals for legal reform and how these proposals might impact the threat of lone wolf terrorism.
Comparative Analysis of Counterinsurgency Operations in Iraq and Afghanistan: New Foresight Approaches to Counterinsurgency Operations with Special Focus on Lone Wolf Terrorism
Authors: Kaivo-Oja Jari
Published: February 2025

In this article a discussion about counterinsurgency, foresight approaches and lone wolf challenge will be provided. Foresight can be defined as a component of strategic counterinsurgency operation with many benefits. Typically social settings of counterinsurgency operation are turbulent, complex and in some cases chaotic. Foresight should be linked to social practices of counterinsurgency agencies. In chaotic and emergent conditions, possibilities of foresight analyses are limited. This is why foresight analyses should be applied in such way that they enable proactive actions. Early warning systems and foresight diagnoses, prognoses and prescriptions should serve directly expected phases of counterinsurgency operations (pre-operation phase, operation phase and phase after counterinsurgency operation). If stakeholders want to develop effective early warning systems in relation to lone wolf challenge, it requires updated information of psychological and sociological behavior patterns of potential lone wolves. Early warning systems (and also weak signal systems) should be tailored to identify and recognize alarming psychological and social signals of potential lone wolf activities. In general, mass counterinsurgency attacks are problematic because larger trauma behavior (with terror behavior) can be expected to happen. In this conceptual study, alternative eight patterns of lone-wolf terrorism will be presented. These identified patterns are based on morphological analysis. To understand lone wolf phenomenon, we need more empirical research about these alternative psychological and sociocognitive patterns. Concerning terror intelligence challenges, we can note that probably the pattern where terror attack is solo, non-directional and not ideologically motivated is the most challenging pattern of lone world terror phenomenon. On the other hand, the social pattern where terror attack is not solo, and it is directional, clearly rationally motivated and also ideologically motivated is the easiest lone wolf pattern to be observed before the attack happens. If we are able to contextualize the lone wolf phenomenon and identify facilitation channels and causal qualities of lone wolf behavior, it is possible to development effective counter operations of lone wolf terror. Other social patterns of lone wolf terror are more or less complex issues to be observed beforehand. Understanding lone wolf terror and explaining causal and complex relationships of lone wolf phenomenon need more research in the future. Especially supportive incentive mechanisms of lone wolf terror (ideological support, operational support and psychological support) need more scientific attention. Issues of anti-fragility, resilience, flexibility, adaptability, artificial intelligence support, and weak signal sensors are going to be critical challenges in the global battle against lone wolf terrorism.
Assessing Terrorism and Counterterrorism in the Maghreb
Authors: Bartolucci Valentina
Published: February 2025

The spectre of terrorism still afflicts North Africa. There is no state in the Maghreb which has not experienced terrorism and there are indications that the threat is on the rise. Moreover, the worsening of socio-economic conditions in the region as well as the political turmoil in the Middle East have further fuelled the rise of political and radical terrorist movements in the Maghreb and neighboring areas. This article aims to provide an overview of the threat and spread of terrorism in the Maghreb, and to assess the counter-terrorism approaches of the three countries under review – Algeria, Morocco, and Tunisia. The analysis reveals a story that is more complex and nuanced that one may assume and highlights the extent to which North Africa has been neglected in academic and policy debates on terrorism and counter-terrorism. It emerges that the actual security situation in the region is particularly volatile, but also that the cards of both an Islamist threat and the menace of terrorism have been at times overplayed by politicians and the media with lasting implications both in terms of human rights violations as well as the security point of view.
EMG data analysis of Seizures
Authors: Conradsen Isa  , Wolf Peter  , Beniczky Sándor
Published: February 2025

The neuromuscular junction connects the motor nervous system with the muscles. Thus, measuring the electric signals in the muscles provides information about the function of the motor cortex. We used quantitative analysis of surface electromyography (EMG) signals to characterize the pathophysiology of convulsive seizures. We found specific EMG features for convulsive seizures, and quantitative characteristics distinguishing generalized tonic and generalized tonic-clonic seizures (GTCS). Based on these EMG features we developed a neurophysiological biomarker for GTCS. This proved to be accurate in distinguishing between GTCS and convulsive psychogenic non-epileptic seizures. In consequence, an algorithm was created which detected GTCS with a high sensitivity and specificity. In this chapter we give a synopsis of our findings on quantitative analysis of surface EMG during epileptic seizures, with focus on clinical and biomedical applications.
Posture detection based on a waist-worn accelerometer: an application to improve Freezing of Gait detection in Parkinson's disease patients
Authors: Rodríguez-Martín Daniel  , Samà Albert  , Pérez-López Carlos  , Català Andreu  , Cabestany Joan  , Browne Patrick  , Rodríguez-Molinero Alejandro
Published: February 2025

Freezing of Gait (FoG) is one of the most disabling symptoms in Parkinson's disease (PD). Current algorithms to detect FoG are based on wearable inertial systems which relies on the frequency response given by the inertial signal. However, these algorithms have only been evaluated under laboratory conditions causing that, in real life, they present false positives, reducing the reliability of the algorithm. This paper presents the evaluation of 20 PD patients in their homes and the inclusion of a posture algorithm in order to contextualize FoG detection. This algorithm improves the optimal FoG detection algorithm specificity from 74.5% to 79% (4.3%) while in average improves specificity from 69.9% to a 74.6% (4.7%) preserving the sensitivity. In some patients, those who performed more false positive tests, specificity could increase up to 11.95% keeping the sensitivity.
Wearable Solutions Using Bioimpedance for Cardiac Monitoring
Authors: Ulbrich Mark  , Mühlsteff Jens  , Reiter Harald  , Meyer Christian  , Leonhardt Steffen
Published: February 2025

Monitoring of a patient's vital signs in their home using some form of wearable technology is of increasing importance and interest. Preferably, patients should be able to operate the system and perform the measurements themselves in a comfortable, easy and reliable way. Until now, only heart rate and rhythm measurements, e.g. obtained from the electrocardiogram or photoplethysmogram, have been realized in a home care scenario. Particularly interesting for telemonitoring applications are the hemodynamic measures such as stroke volume, systolic heart phases, or the development of edemas. The relatively simple bioimpedance technique has a long research history and has proven useful to detect changes in these latter measures. In addition, the technique can be implemented in wearables, such as functional textiles. This chapter discusses the basics of bioimpedance measurements and provides insight into the technical and design challenges relevant for the development of system components based on our experience to date.
Deep foundations in Mexico City soft soils
Authors: Auvinet-Guichard Gabriel  , Rodríguez-Rebolledo Juan-Félix
Published: February 2025

A general overview of the different solutions to the problem of foundation of buildings on highly compressible soft soils such as those found in Mexico City valley is presented. Special attention is given to deep foundations systems that were developed to control settlement or protruding in consolidating soils. Recent techniques for modeling the behavior of deep foundations are also reviewed.
Porosity/binder ratio
Authors: Consoli Nilo Cesar  , Festugato Lucas
Published: February 2025

The porosity/binder ratio, η/Civ, is possibly the main development in the field of soil stabilization over the last many decades. η/Civis shown to be the controlling factor of artificially cemented materials mechanical behavior. Experimental results were presented to highlight this ratio applicability for determination of artificially cemented soils unconfined compressive strength, splitting tensile strength, triaxial compression behavior, shear and volumetric stiffness, stress-dilatancy behavior and strength envelopes. Moreover, fiber reinforcement use and its benefits were presented as a solution for geotechnical problems and as a future challenge to be incorporated into engineering practice.
TBM Pressure Models – Observations, Theory and Practice
Authors: Dias Tiago Gerheim Souza  , Bezuijen Adam
Published: February 2025

Mechanized tunnelling in soft ground has evolved significantly over the last 20 years. However, the interaction between the tunnel boring machine (TBM) and the ground is often understood through idealized concepts, focused mostly on the machine actions in detriment of the reactions from the ground. These concepts cannot be used to explain several mechanisms that have been observed during the construction of mechanized tunnels. Therefore, this paper presents the path from field observations to the theoretical developments to model the TBM-ground interaction more realistically. Some ideas on how these developments can be applied into practice are presented. Finally, a discussion is proposed about how an effective collaboration between academia and industry can alleviate the current concentration of knowledge in the state of practice.
Tailings Dams and Hydraulic Fills – The 2015 Casagrande Lecture
Authors: Valenzuela Luis
Published: February 2025

The significant growth of the metallic mining industry over the last few decades has made the construction of tailings deposits of large dimensions necessary, tailings being the fine mining waste resulting from the milling and concentration processes. In some cases the dams required to contain these tailings could reach a considerable height. The most common types of tailings dam in mining are the tailings sand dam, a special kind of hydraulic fill dam, for two main reasons: because such dams need to be built over a long period of time, and due to the low cost of sand available from the tailings. Both types have not only a similar construction method in common, but also negative social perception due to the history of failures associated with the original designs of these dams. These designs have evolved with time to more adequate schemes enabling a much better performance. Although these types of dam differ in many aspects, such as main objective, source of the sand for construction, and the total construction time, the evolution of their designs has some interesting similarities. At this Conference, critical aspects in the performance of both types of dams will be discussed, together with the evolution of their original designs.
Geotechnical Characterization of a Pyroclastic Sand and Tuff
Authors: Covassi Pedro A.  , Zeballos Marcelo A.  , Gorosito Sofía I.
Published: February 2025

This paper reports the geotechnical characterization of pyroclastic sand and a tuff formation, both finding at the Valley of Pichin Leufú River, Río Negro province, Argentina. The geological origin of these materials is the precipitation of volcanic ash. The materials studied present singular mechanical characteristics. Tests results show that both materials present a low unit weight and low plasticity, but high liquid limit, high compressibility and high strength parameters. The aim of the geotechnical characterization is to determine an exhaustive set of both stiffness and strength parameters. A series of conventional laboratory techniques, such as one-dimensional compression, triaxial compression and direct shear tests were performed in order to determine both deformational and strength parameters of the pyroclastic sand. On the other hand, unconfined compression tests were performed on specimens of the tuff rock in order to characterize this material. Also, a series of direct shear tests in concrete-tuff interfaces were performed in order to evaluate the skin friction for different of normal stress levels and concrete roughness. A comparison with other tests results finding at the literature also are presented.
Stress-Deformation Modeling of Geosynthetic-Reinforced Pavement Structures at Different Water Contents
Authors: Baltodano Goulding Rafael  , Leiva Padilla Paulina
Published: February 2025

The use of geosynthetic materials to improve the bearing capacity and deformability behavior of pavement structures is a technique often used by engineers. The effectiveness of the geosynthetic as a reinforcing material relies on certain physical mechanisms and some simplifications made about the behavior of the soil being improved. The transmission of stresses from the soil, bases or subgrades, to the geosynthetic material depends on the stiffness of the soil. The compaction process of such soils becomes very important as the stiffness of compacted soils is such that stresses can be transmitted to the geosynthetic at relatively low deformations. However, the deformation behavior of soils varies with the degree of saturation and a soil that is expected to have a stiff material behavior might exhibit a more ductile deformation behavior as the water content in the soil increases, or as a double-peak shear strength behavior as a function of water content and consistency limits is developed. Therefore, less stresses could be transmitted to the geosynthetic but deformations could be greater, and this can certainly affect some analysis assumptions. A series of shear strength tests on different fine grain soils were used to obtain deformability parameters at different water content but at similar void ratios. These soils were used to represent subgrade materials in a computer model of a pavement structure. The results of this model might provide a better understanding of the influence that varying degrees of saturation, produced by climatic conditions or poor drainage designs, could have on the deformation behavior of pavement structures reinforced with geosynthetics.
Geotechnical characterization of calcareous sands in the northeastern coast of Venezuela
Authors: Vieira Faria Nelly  , De Ponte Fernandes Diana
Published: February 2025

The term calcareous may be applied to sediments, sedimentary rocks or soils which are formed or contain high proportion of calcium carbonate (CaCO3). The calcareous sediments are usually deposited in shallow water and close to the coast because the precipitated calcium carbonate comes mainly from organisms that required terrigenous nutrients. These sediments exist in different forms, in each case having distinctive properties between them, depending on the sedimentary facies that controls their deposition process. In general there is limited literature related to carbonate materials in the Caribbean. Most of recent information comes from Australia where they have been extensively studied. This article shows the characterization of carbonate soils in the northeastern region of Venezuela. For this study, data from two campaigns conducted offshore Venezuela are studied. Water depth in the area is approximately 100 m. Samples were taken with 3" Shelby (pushed) and 2 1/4" Shelby (driven). Additionally, CPT tests were performed. Basic classification tests including carbonate content and advanced geomechanical tests such as direct simple shear (ASTM D6528, [1]) and controlled-strain loading consolidation tests (ASTM D4186, [1]) are performed. All data obtained in field and laboratory is processed and analyzed in order to estimate their characteristics, behavior and in-situ state. This paper presents the characterization of the calcareous sands incorporating geological and geotechnical data with the aim at a future comparison with analogous materials in other parts of the world. Main findings can be summarized as: a) the methodology for reconstituting this sort of soil for maximum and minimum density should be improved, and b) samples did not suffer fragmentation and did not (or barely) experienced compressibility under the applied stresses.
Seismic Wave Velocities of Soft Clays Measured with Piezoelectric Crystals in an Oedometer
Authors: Diaz Pardave Miguel  , Ovando-Shelley Efraín
Published: February 2025

We present some of the results of an experimental investigation aimed at characterizing soil samples in terms of seismic wave velocities estimated from measurements with piezoelectric crystals. Specimens of Mexico City Clay were mounted on an instrumented consolidometer in which we obtained compression and shear wave velocities. The paper examines the close field effect on shear wave velocity measurements by looking at the signals recorded in the piezoelectric receivers in response to sinusoidal signals induced at different frequencies that ranged between 1 and 7 kHz. We use the specimens' transfer functions to obtain their natural frequencies; with them and with a dimensionless parameter (the quotient of the distance between the emitter and the receiver and wave length), we put forth a procedure to determine the minimum frequency required to avoid near field effects and, hence, to obtain reliable values of shear wave velocities.
Determination of the Maximum Density of Carbonate Silty Sands
Authors: Naghavi Alhosseini Naemeh  , El Naggar M. Hesham  , Sadrekarimi Abouzar
Published: February 2025

The range and values of the limit densities are important in interpreting laboratory results. In this study, the available procedures reported in the literature and ASTM standard are evaluated to identify their limitations in maximum density testing on well-graded carbonate silty sand samples with different fines content. Four levels of fines content in the samples are studied and it is revealed that particle degradation and segregation can affect the results of density tests. As a result, appropriate test methods that preserve the original soil gradation and create uniform soil distribution should be employed in determining soil densities.
Shear strength and stiffness anisotropy of geologically aged stiff clays
Authors: Jardine Richard  , Brosse Amandine  , Coop Matthew  , Hosseini Kamal Ramtin
Published: February 2025

This paper considers the deformation behaviour of four geologically aged, medium-plasticity, heavily overconsolidated stiff clays that affect a broad swathe of infrastructure projects in the SE of the United Kingdom. Static triaxial and hollow cylinder stress path experiments on high quality samples are examined along with dynamic multi-axial bender element and resonant-column measurements. Patterns of undrained shear strength anisotropy are revealed that are governed by the clays' meso and micro-structures. The clays are brittle in shear and their stiffness characteristics are shown to be markedly anisotropic, highly non-linear and pressure dependent. The results obtained have many implications for practical geotechnical engineering.
Improved laboratory techniques for advanced geotechnical characterization towards matching in situ properties
Authors: Viana da Fonseca António  , Ferreira Cristiana  , Soares Marisa  , Klar Assaf
Published: February 2025

Laboratory tests are well recognized as highly appropriate for defining the engineering properties of geomaterials, in terms of constitutive law parameters for modeling geotechnical engineering problems. The strong development of advanced techniques, both in equipment and in data interpretation, has increased the confidence in laboratory testing, while on the other hand the limitations due to the quality of soil sampling with depth and the spatial representativeness of the samples are less consensual. Still, the development of new methods for assuring high quality samples is increasing, together with sampling quality assessment by non-destructive methods using vibration wave velocities. Interpretation methods of in situ tests for ground characterization has also evolved significantly, increasing the reliability of these methods. Their versatility to cover large areas on site and the fact that these tests are, in principle, performed at the actual state (physical and stress) conditions, as well as the improvements in the correlations between field tests and hydraulic and geomechanical parameters, allows joining the quality of data and theoretical approaches, namely through critical state soil mechanics. Current techniques are usually associated either with very low stress-strain levels, such as in geophysical surveys, or with very high stress-strain levels, near failure, as in dynamic penetration tests. This practice means that the complete range of stress-strain response is rarely covered in the investigation. Exceptions can be made when using the pressuremeter test, especially the self-boring technique, although time-consuming and expensive. New research trends are making use of a single technology for characterization at different scales (e.g. element, layer and global characteristics), which is the case of the use of high-resolution fiber optic distributed sensing technology for in situ moduli profiling and in laboratory element testing.
Behavior of compacted unsaturated soil in isotropic compression, cyclic and monotonic shear loading sequences in undrained condition
Authors: Rasool Ali Murtaza  , Kuwano Jiro  , Tachibana Shinya
Published: February 2025

Unsaturated soils are most common in geotechnical practice. In order to study mechanical behavior of unsaturated soil a series of constant water content tests were performed in this study. Soil specimens were tested under isotropic loading-unloading, monotonic and cyclic loading sequences to study the effects of stress history on change in void ratio and suction, and on shear characteristics of unsaturated soil. It was concluded that the mechanical behavior of silty soil named as DL clay is not affected significantly by loading sequences incorporated.
Element Tests On Lumpy Inhomogeneous Soil And Their Interpretation
Authors: Shi X.S.  , Herle I.
Published: February 2025

Lumpy soils are inhomogeneous materials which can be encountered in open pit mining. The initial structure of the clayfills is similar to that of the granular material, which is stable due to the absence of a reconstituted soil. However, it might be transformed into a lumpy-composite structure due to the influence of climate. The lumps are randomly distributed in the reconstituted soil, which can be bounded by two basic configurations. For this purpose, two series of triaxial shear tests were performed on artificially prepared samples with parallel and series configurations of the different constituents. The test results show that the shear strength of the series samples is only slightly higher than that of the weaker constituent and the strength of the parallel samples lies between those of the constituents. For the parallel samples, there is a significant difference in the stress concentration ratio at different consolidation stress; while, the strain concentration ratio of the series samples is not significantly affected by the consolidation stress.
Effect of Cement Type on the Mechanical Behavior of Fiber Reinforced sands
Authors: Nikzad Navid  , Hamidi Amir
Published: February 2025

Early attempts to increase the soil strength by mixing it with other materials date back 3000 years ago in construction of ziggurats when the soil was mixed with plant roots. Coupled usage of cement and fiber in soil, however, refers to more recent years. Reinforcement with cement and fiber is one of the soil improvement methods for increase in bearing capacity and reduction of settlements. Cemented soils are usually found naturally, however, artificially cemented samples are widely used in the laboratory to investigate deformation and shear strength characteristics due to the limitations in undisturbed sampling. In present study, series of conventional triaxial tests were carried out to investigate the effects of cement type on the mechanical behavior of fiber reinforced sand. Accordingly, Portland cement type (II), hydrated lime and gypsum plaster were used as the cementing agents. The cement content was 3% (dry wt.) of the base soil. Fibers 0.012 m in length and 23 μm thicknesses were added at 0.0%, 0.5% and 1.0% (dry wt.) of the sand-cement mixture. Samples were prepared at 70% relative density and triaxial tests were performed under confining pressures of 100, 200 and 300 kPa. Samples cemented with Portland cement were cured for 7 days in humid room, however, samples with hydrated lime cured for 7 days in a constant temperature about 40°C and samples with gypsum cured for 24 hr in a constant temperature about 50°C. Samples with Portland cement and hydrated lime were tested in saturated condition but gypsum cemented ones were tested in dry condition. The results of experiments showed that fiber inclusion increases peak and residual strengths, axial strain at failure and energy absorption for all cement types. For the mentioned curing condition, samples cemented with Portland cement indicated the most shear strength and samples with hydrated lime showed the least value. Also, fiber addition was more effective on the peak shear strength of samples cemented with hydrated lime and had the least influences on the strength of gypsum cemented samples.