bluuebunny/crossref_metadata_2025 huggingface dataset:
Parametric identification of the dynamics model in the system fertilizer-soil-plant
Authors: Четырбоцкий В.А. , Четырбоцкий А.Н.
Published: October 2021

Выполнена математическая формализация уравнений модели, для построения которой использовалась концепция системы ресурспотребитель. В рассматриваемом случае потребителем выступает биомасса растений, а ресурсомраспределенные в узкой прикорневой зоне растений основные элементы его минерального питания (азот, фосфор и калий). Динамические уравнения модели следуют основному положению химической кинетики, согласно которому результат взаимодействия динамических переменных в системах рассматриваемого профиля определяется их произведением. Выполнена оценка параметров и установлена адекватность модели выборочным распределениям. В качестве выборочных распределений используется массив экспериментальных данных роста яровой пшеницы (Красноуфимская-100) на торфяной низинной почве, предварительная почвенная обработка которой проведена с помощью азотных, фосфорных и калийных удобрений.

Modern mathematical models for the simulation of dynamics in the fertilizer-soil-plant system, the components of which are agricultural plants, soil microorganisms and elements of their mineral nutrition, are considered. Based on the analysis of the adopted provisions, a model that takes into account the relationships and the specific nature of the joint changes in its components has been developed. The mathematical formalization of the model equations is carried out, for the construction of which the concept of the resourceconsumer system was used. In this case, the consumer is the biomass of plants, and the content of the main elements of its mineral nutrition distributed in the narrow basal zone of plants is a resource. The dynamic equations of the model follow the basic principle of chemical kinetics, according to which the result of the interaction between dynamic variables in the systems of the profile in question is determined by their product. The equations also contain the self-limitation factor, which sets the growth rate of the curve for the logistic equation and the specific rate of the model variables saturation effect. Thus, the specific rate of change in biomass is determined by its natural growth rate, the weighted sum of the nutrient contents in plants, and intraspecific competition. The rate of change in the content of these elements per unit of biomass is proportional to their current content in the rhizosphere and to the factor of the mutual influence of the elements on each other. The parameters are estimated and the adequacy of the model to sample distributions is established. An array of experimental data on the growth of spring wheat (Krasnoufimskaya-100) on peat lowland soil, the preliminary soil treatment of which was carried out using nitrogen, phosphorus, and potassium fertilizers, is used as sample distributions. The coefficients obtained as a result of parameter estimation and the calculated distributions of model dynamic variables with a sufficiently high degree of adequacy correspond to their experimental distributions and reflect the real situation of the system evolution.
Jugendpsychiatrie, Familie und Adoleszente – Sozialisationstheoretische Annäherungen an die Figur des institutionellen Dritten als strukturellem Krisenauslöser
Authors: Becher Julia , Schulmeister Janina , Silkenbeumer Mirja
Published: October 2021

Werden Jugendliche aufgrund psychosozialer Krisen in einer jugendpsychiatrischen Klinik stationär behandelt, tritt diese als Repräsentantin des medizinisch-therapeutischen Handlungssystems und spezifische Form der institutionellen Krisenbearbeitung als institutioneller Dritter in die Dyade aus Adoleszenten und deren Familien ein. Gestützt auf Erkenntnisse rekonstruktiver Fallstudien wird der heuristische Mehrwert einer triadischen Perspektive auf Sozialisations- und adoleszente Bildungsprozesse im Schnittfeld der different strukturierten Sozialisationsräume Familie und Jugendpsychiatrie ausgeführt. Anhand zweier kontrastierender Fälle von psychiatrieerfahrenen Jugendlichen werden zwei Modi der familialen Bearbeitung der mit der Erweiterung des institutionellen Dritten verbundenen strukturellen Krisenkonstellation herausgearbeitet. Abschließend wird der Ertrag dieser triadische Strukturen berücksichtigenden Heuristik für eine fallrekonstruktive Forschungsperspektive auf Sozialisationserfahrungen in Institutionen diskutiert.
THE MANAGEMENT ALGORITHM OF CHILDREN WITH REFRACTORY GLAUCOMA
Authors:   Tashkent Pediatric Medical Institute of the Republic of Uzbekistan, Nazirova Zulfiya Rustamovna
Published: October 2021

This article presents an analysis of the results of the algorithm of management of children with refractory glaucoma which included: preparation and carrying out surgical treatment, analysis of postoperative period of children with refractory glaucoma. Thetotal number of children diagnosed with glaucoma was 478. Of them 82.1%, 410 children underwent surgical treatment. 30.2% (125 children) needed reoperation. The results of the analysis of the clinical and functional state of the visual organ in children for the period from 2016 to 2020 are given. The indications for repeated surgical treatmentwith the use of drains are described in detail. Keywords: refractory glaucoma, drains, diagnosis, congenital glaucoma
OPTIMIZATION OF INTENSIVE THERAPY FOR BURN SHOCK
Authors:   Samarkand state medical institute of the Republic of Uzbekistan, Jumanov Xusniddin , Mustafakulov Ishnazar , Korabaev Xudoyberdi , Hursanov Yokubjon , Ergashev Akobir
Published: October 2021

The literature provides about 100 different definitions of the concept of shock(G. Bernard, 2001). A large number of definitions of the concept are directly dependent on the reasons that caused it. Burn shock is the first stage of burn disease and develops when the surface of the body is affected by an area of 10-15% for superficial and 5-10% for deep burns.This article discusses the optimization of intensive therapy for burn shock.Keywords:pathogenesis, stages of burns, treatment principles, Evans formula, criteria for recovery from shock
FUNCTIONAL METHODS OF EARLY DIAGNOSTICS OF AGE MACULAR DEGENERATION.(LITERATURE REVIEW)
Authors:   Republican Specialized Scientific and Practical Medical Center of Eye MicrosurgeryTashkent, Uzbekistan, Yusupov Azamat , Ziyoviddinov Mukhiddin , Mukhanov Shavkat , Sobirov O.O.
Published: October 2021

This article provides an unsystematic literature review devoted to analyzing the currently existing methods of functional diagnostics for age-related macular degeneration.The essence, advantages and disadvantages, and literature data on the use of such methods asphotostresstest, electrooculography, dark adaptation study, contrast sensitivity function assessment, light and color sensitivity study,electroretinographyand critical flicker fusion frequencyare described.Based on the analysis of literature data, itis shownthat currently, there is a need to searchfor informative and accessible methods of functional diagnostics in age-related macular degeneration, especially for its early diagnosis. The analysis has shown that the existing methods are mainly aimed either at fixing secondary morphological changes in the layer of pigment epithelial cells, at identifying the pathology of the pigment epithelium in conjunction with determining the function of photoreceptor elements, or at a comprehensive assessment of the structures of several layers of the retina. Keywords:age-related macular degeneration; methods of functional diagnostics; photostress test; electrooculography; contrast sensitivity
TWO HEARTLANDS THEORY AND CENTRAL ASIAN CHOICE
Authors:   the Non-Governmental Research Institution“Knowledge Caravan” of Uzbekistan, Tolipov Farkhod
Published: October 2021

The articlepresents the new theoretical approach to modern geopolitics. It argues that nowadays both old and new Heartlands coexist and clash with each other. This is the struggle betweenimperial and autocratic world –on one side, and free and democratic world –on the other side. Both have geopolitical background and strength. The analysis of the context of development of Central Asian region and geopolitical trends it is exposed to reveals profound challenge of choice between two Heartlands. This analysis also contributes to existing arsenal of the theory of International Relations
COMPARATIVE STUDY OF THE EXPERIENCE OF REFORMS IN THE NEW UZBEK-CHINESE RELATIONS
Authors:   Tashkent State University of Oriental Studies of the Republic of Uzbekistan, Shazamanov Shoazim Ibragimovich , Sharapov Anri Abdullaevich
Published: October 2021

The article focuses on the following aspects of the issue: the pragmatic policy of the Republic of Uzbekistan in world politics and the analysis of their features; Documents defining the relations between Uzbekistan and China; study the aspects ofcooperation for peaceful coexistence and development; analysis of the ideas of Uzbek and Chinese researchers on the relations between the two countries; General aspects of reforms in Uzbekistan and China; Capital investments of Chinese entrepreneurs in the development of the Uzbek economy in the regions of the country; cooperation in the field of military, tourism, as well as the policy of the PRC on railway transit with Central Asia to Europe
CERTAIN ASPECTS OFTHE FORMULATION OF THE MODERN WORLD OF DEMOCRATIC POLITICAL THINKINGIN GOVERNANCE
Authors:   Academy of Sciences of the Republic of Uzbekistan, Ruziev Ravshan
Published: October 2021

The modern mechanisms of public administration in the society of Uzbekistan, the socio-political aspects of the selection and placement of senior personnel, the liberalization and democratization of the spherehave been researched in the article. In particular, in the speeches of scientists of the East and the head of state, the analysis of aspects related to this problem is presented. The question of the role of democratic thinking in modern governance and itsimpact on sustainable development is studied in detail.The responsibility of the head for improving public administration, his spiritual, professional and social competence, as well as the implementation of political thinking there have been also discussed topical issues
MODERN MEANS AND MECHANISMS OF CIVIC ACTIVISM AND INITIATIVE IN SOCIETY
Authors:   Academy of Public Administrationunder the President of the Republic of Uzbekistan, Shodiev Nurali
Published: October 2021

The article examines the development trends of modern networks of political communication, the growing influence of social networks on the Internet on the civic engagement of citizens. At thesame time, the role of various blogs in expanding citizen participation in public administration is scientifically analyzed.The analysis ofsocial networks, blogs and various media resources used on the Internet as a platform and tool for civic initiatives and activity in society is carried out. The article also discusses modern methods and techniques for using political communications to increase civic engagement.
Reactivity to Daily Self-Monitoring of Cannabis Use in Biological Females
Authors: Isaacs Jason , MacKinnon Sean , Joyce Kayla , Stewart Sherry
Published: October 2021

Assessment reactivity involves changes to behaviours from self-monitoring those behaviours (Nelson & Hayes, 1981). In the substance use field, reactivity has been identified both as a potential confound in daily diary research (Cohn et al., 2015) and as a possible intervention tool in clinical practice (Cohn et al., 2018). Reactivity to daily self-monitoring of alcohol and tobacco use has been inconsistent in prior research. Reactivity to daily self-monitoring of cannabis use quantity has received far less study. This study involved secondary analyses of data from N = 88 females who self-monitored their cannabis use for 32 days. We examined objective reactivity of cannabis use to daily self-monitoring by assessing changes in daily cannabis use over 32 days. We also explored participants’ perceptions of the impact daily self monitoring had on their cannabis use at study completion (i.e., subjective reactivity). In hurdle models testing objective reactivity, neither probability of cannabis use, nor quantity of cannabis use, changed significantly over the study period. Many respondents (45%) reported no subjective reactivity, though a slight majority (55%) reported some subjective reactivity. Subjective reactivity did not moderate objective reactivity over time; however, higher subjective reactivity was significantly associated with increased variability (interquartile range [IQR]) in cannabis use across the self-monitoring period. Overall, reactivity appears unlikely to confound research utilizing daily diary cannabis measures, and daily self-monitoring of cannabis use may be unlikely to serve as a useful stand-alone intervention for reducing cannabis use in non-treatment-seeking individuals. Potential clinical implications of the novel finding of a link between subjective reactivity and objective cannabis use variability are discussed.
Health outcomes among adults initiating medical marijuana for chronic pain: A 3-month prospective study incorporating ecological momentary assessment (EMA)
Authors: Wang Yan , Jacques Jennifer , Li Zhigang , Sibille Kimberly , Cook Robert
Published: October 2021

In response to the need of more rigorous data on medical cannabis and chronic pain, we conducted a 3-month prospective study incorporating ecological momentary assessment (EMA) to examine the effects of medical cannabis on pain, anxiety/depression, sleep, and quality of life. Data were collected from 46 adults (Mean age=55.7±11.9, 52.2% male) newly initiating medical cannabis treatment for chronic pain. Participants completed a baseline survey, EMA for approximately 1 week pre- and up to 3 weeks post- medical cannabis treatment, and a 3-month follow-up survey. The self-reported EMA data (2535 random and 705 daily assessments) indicated significant reductions in momentary pain intensity (b = -16.5, p < .001, 16.5 points reduction on 0-100 visual analog) and anxiety (b = -0.89, p < .05), and significant increase in daily sleep duration (b = 0.34, p < .01) and sleep quality (b = 0.32, p <.001) after participants initiated medical cannabis for a few weeks. At 3 months, self-reported survey data showed significantly lower levels of worst pain (t = -2.38, p < .05), pain interference (t = -3.82, p < .05), and depression (t = -3.43, p < .01), as well as increased sleep duration (t = 3.95, p < .001), sleep quality (t = -3.04, p < .01), and quality of life (t = 4.48, p < .001) compared to baseline. In our sample of primarily middle-aged and older adults with chronic pain, medical cannabis was associated with reduced pain intensity/inference, lower anxiety/depression, and improved sleep and quality of life.
What food do we feed girls as artist upon?
Authors: Malpezzi Chiara
Published: October 2021

Virginia Woolf in A room of one’s own (1929) builds a strong connection between food and the material conditions of women writers, asking herself: what food do we feed women as artists upon? From this point of view, food can be considered a metaphor for the achievement of both artistic and gender equality. Hence, my paper aims to outline the relevance of this under-investigated topic in children’s literature, focusing on feminist Künstellromans, namely stories about a female artist’s journey to maturity. Drawing from the methodology of Nodelman, I will investigate two opposite narrative situations: famine and feast. In the first one, the lack of food represents the struggle in the artistic development, often caused by a hostile educational environment, while, in the second, nourishment can be interpreted as fruitful sustainment for the body and soul. My hypothesis seeks to underline how food and girls’ development as women and artists intertwine in children’s literature, figuring out a possible answer to Woolf’s question.
Tripartite school conflicts and non-consensual democracy. An attempt of autoethnographic analysis
Authors: Pilas Martyna
Published: October 2021

The article presents an analysis of four school conflicts on the parent-teacher line. I am trying to prove that the teacher-parental conflict is always actively involved with the student, with his paidocentric position in the family, subjectivity and authority as the third party in the process of democratic dialogue (B. Śliwerski 2007). I use the analytical autoethnography method, the most appropriate from my point of view, based on a subjective approach, the analysis of feelings and reactions, self-observation, first-person narrative, analysis of the researcher's notes and own narratives, forcing the full participant in the studied environment (complete member researcher), analytical reflexivity, data transcending. (C. Ellis 2004, L. Anderson 2014). The school in my article is perceived as a place of conflict which is an unobvious expression of democratic dissent and a difficult way of achieving commonality, which is a condition of democracy. The conflict is an indispensable social element and the basis of relations of subjective character, characteristic of democratic forms of social life (Rancière 1999, Coser 2009, Beaurdieu 1990). Confronting this with knowledge developed around the idea of non-consensual democracy, which is based on discord (dissensus) after the reading (J.Rancière 1999, L. A. Coser 2009, L.Koczanowicz 2015, K. Wajszczyk 2015, M. Mendel 2002) I assume that not only the occurrence of conflicts is a problem, but the lack of orientation on the positive meaning of the situation of disagreement and attitudes related to attaining it and ensuring equality for others in the practice of dialoging participants in school life.
How can the construction industry serve the needs of a society threatened by climate change?
Authors: Cook Mike
Published: October 2021

Construction serves the needs of society with infrastructure that provides safe and healthy places in which to live, work, learn and play, with transport that serves trade and leisure, and with industries that drive our economic prosperity. Yet in serving important societal needs, construction has also been a major contributor to the degradation of the planet’s natural resources and acceleration of climate change. These harmful impacts are now threatening human prosperity and safety. The Henderson Colloquium, organised by IABSE UK in September 2020, asked key players across multiple sectors of the construction industry this question: How can the construction industry serve the future needs of a society threatened by climate change? The discussions revealed the need for deep-seated change across all elements of the industry including our business models, our professional institutions, education, and government policy. These outcomes are being shared in this paper to stimulate thinking in a wider, international forum of construction professionals.
Risk intelligence of structural systems: concepts and recent developments
Authors: Song Junho
Published: October 2021

To ensure and maintain reliability of civil infrastructures against rapid urbanization, globalization, population growth, and climate change, the concept of risk intelligence is needed. Four elements – identification, integration, inference, and implementation – are proposed and discussed from the viewpoint of data-information-knowledge flow. Recent research developments are presented to provide examples and identify topics of further research toward risk intelligence.
Materials in bridge engineering: creating a more sustainable future
Authors: Wong Mary
Published: October 2021

Building infrastructures are essential to the future of cities and urban growth. Since material is the gateway to the realization of bridge design concepts, it plays a vital role in Bridge Engineering. The journey towards future encompasses a key leading driver, Sustainability, that will have an impact on our long-standing engineering practice and shape the future to a more efficient and resilient one.

In this paper, we present principles that show in which direction is the future of materials in bridge construction heading to. For examples, how to optimize materials performance, how materials can contribute positive influence on sustainability, how to reduce materials consumption and how to extend the life span of bridges? Project references based on each principle demonstrate the know- how to create a more sustainable future.
Exploring circularity: Europengineers on piano
Authors: Zonco Audrey , Göttgens Bastiaan , O'Riordan Kieran , Liu Che , Rat Dominique
Published: October 2021

Europengineers organized a design sprint on the theme of reuse, which took place at Setec’s headquarters from the 20th to 22nd February 2020. This was based on a study case: how could the 80 steel frames in the Thales factory be saved from the foundry and reused in another project? What barriers and difficulties would be encountered in such a project?

The teams of twenty engineers shed light on the design stages (find the client, use and shape), the technical challenges (Structural diagnosis and reliability, dismantling, storage) and marketing issues (marketplace, insurability).
The effects of expansion joint design on bridge life-cycle costs - initial investment versus total cost of ownership
Authors: Vide L’eau Arneaux , Yousfi Adel , Meng Niculin
Published: October 2021

The need to maximise long-term value for money supports the consideration of life-cycle costs rather than just initial construction costs when investing in key infrastructure such as bridges. This is especially true in the case of a bridge’s expansion joints, which are much less robust than the structure as a whole yet subjected to continuous movements and dynamic loading. The life-cycle costs of a bridge’s expansion joints may be considered to include not only initial supply and installation costs, but also maintenance and repair costs throughout their service life, and replacement costs, and the user costs associated with maintenance and replacement work – especially those relating to traffic disruption. Increasingly, the effects of avoidable work on the environment should also be considered. This paper will address this topic, discussing issues that should be considered in choosing the optimal solution for any individual structure.
Protection and repair of concrete structures as an important contribution to sustainability
Authors: Retzepis Ioannis
Published: October 2021

Effective protection strategies and repair methods of concrete structures guarantee their serviceability and durability for a long period of time. However, the choice of the “right” materials, according to the code-family EN 1504, does not generally ensure the success of the application. It is the choice of the right system of materials as well as the application rules and quality control which guarantee this success. To achieve this, additional regulations have been introduced in Germany in the past. However, this procedure has been declared illegal according to the decision of the European Court of Justice, so a new way had to be found. This new way is based on the specific requirements for protection and repair of each individual structure and shifts the responsibility to the design engineer.
Overcoming the limitations of recycled concrete aggregates in Belgium
Authors: Zeidan Talina , Farina Xavier
Published: October 2021

In Belgium, the presence of numerous quarries in the Walloon region makes recycled concrete aggregates (RCA) less attractive for structural concrete applications: since the natural aggregates are at reach, it is unprofitable from both a financial and an environmental aspect to use RCA. In addition, the supply of recycled aggregates on the Belgian market is lacking. Only a few recyclers produce type A+ RCA, which could be used in ready-mix concrete, but tend to keep them for their own productions. Furthermore, although the revised Belgian national concrete standard (NBN B 15- 001) allows cast-in-situ concrete to contain higher fractions of recycled aggregates, there is presently no concrete supplier yet certified to produce concrete with recycled aggregates. One should finally note the lack of stimulation or even mandatory incentives by the Authorities to promote the use of RCA. The aim of this paper is to identify the various reasons behind RCA limitations in Belgium and to suggest solutions to overcome them.
The use of a new slab track system in the renovation of the Vierendeel railway bridges in Mechelen
Authors: Berten Karlien , De Pauw Bart
Published: October 2021

The existing ballastless track with wooden sleepers on the Vierendeel bridges in Mechelen will be replaced by a new slab track system with continuously welded rails across the bridge. Additionally, the rails will be positioned eccentrically on the stringers due to track optimization. This paper describes the design and implementation of this new modular track system that consists of prefabricated fully welded steel frames that are bolted onto the existing superstructure. During the design stage, focus was on the required load transfer via the steel frame to the bridge superstructure, on the large difference in steel characteristics between the old and new material and on the position of joints and fastenings. Lateral and longitudinal stiffness of the track was tested on a prototype and the final solution was already installed and successfully implemented on one bridge. In addition, field tests in relation to rail-bridge interaction have started.
The circular arch viaduct: reduce, re-use & recycle in practice
Authors: Smits Joris , Ney Laurent , van Roosbroeck Thijs , Spaargaren Tom
Published: October 2021

This paper describes a proposal for a Circular Arch Viaduct. The proposal was submitted for a competition for innovation launched by Rijkswaterstaat, the Dutch Directorate-General for Public Works and Water Management, under the title ‘SBIR (Small Business Innovation Research) Circular Viaducts and Bridges’. The authors of this paper are part of a consortium consisting of BESIX NL and Ney & Partners. They have currently rounded up the first phase of the competition (Figure 1).

Our society has become accustomed to the permanent availability of raw materials; our economy has been running on them for decades. At the same time, the demand for mobility and reliable infrastructure continues to grow. How do we transform the construction industry to use 50% less primary raw materials in 2030 on the way to full 100% circularity in 2050? To answer this question the Circular Arch Viaduct was developed, based on three principles: (1) the reduction of raw materials, (2) the differentiation of materials in function of required strength, and (3) the reduction of waste through re-use and recycling.

Figure 1. The current concept of the Circular Arch Viaduct.
Re-using existing prefabricated prestressed concrete girders
Authors: Vergoossen Rob , van Eck Gert-Jan , Bakker Rien
Published: October 2021

The future of bridge and overpass design is to be fully circular. To reach that goal many innovations in construction should be made. One of the first steps is to alter the mainly existing linear construction sequence. Therefore, Royal HaskoningDHV started the innovation of re-using prefabricated concrete girders for new overpasses and bridges. The economic and technical feasibility is researched as well as the impact on climate and emissions. To prove our concept, an overpass is deconstructed, and the 40-year-old prefabricated concrete girders are disassembled and put on transport, instead of crushing them to aggregate. In a temporary storage the girders are inspected, repaired, adapted and certified. So, they are fit for their future use in a new structure. Structural assessments, environmental impact and costs calculations are made for a case study. It is concluded that re-using prefabricated girders is technical and economical feasible, with a remaining lifespan of at least 100 year. Up to 44% of CO2-eq. emissions can be saved and even 61% of abiotic depletion (in Sb-eq.). The main obstacle is the unawareness at the different stakeholders that re- using these high-quality girders is possible and these girders can function for the next century.
Crafting a framework of embodied carbon education, tracking, and reduction for US-based structural engineers
Authors: Gryniuk Michael , Kestner Dirk , Lombardi Luke , Stringer Megan , Webster Mark , Wingo Lauren , Yang Frances
Published: October 2021

Achieving reductions to embodied carbon, the global warming potential emissions due to the production of materials, is an essential component to meeting science-based climate targets. Studies have shown that a significant portion of embodied emissions within the built environment are due to structural materials. However, many structural engineers are, not only uneducated in the concept of embodied carbon, but also not aware of the role their decisions can make in addressing climate change. This is further exacerbated by a profession that does not have sufficient structural system embodied carbon benchmark information to make important and informed early design decisions. This required the collaborative development of a structural engineering commitment program, SE 2050, that is supported by leading professional organizations to spur the education and transformation of the profession.
A numerical approach for the assessment of crosswind effects on barrier-protected trains running on bridges
Authors: Porpiglia Giuseppe , Schito Paolo , Argentini Tommaso , Zasso Alberto
Published: October 2021

This paper introduces a new methodology to assess the influence of a windscreen on the crosswind performance of trains running on a bridge. Considering the difficulties encountered in both carrying out wind tunnel tests that consider the vehicle speed or complete CFD analyses, a simplified CFD approach is here discussed. Instead of simulating simultaneously the windscreen plus the moving train, the numerical problem is split into two parts: firstly, a simulation of the windshield alone is used to extract the perturbed velocity profile at the railway location; secondly, this profile used as an inlet condition for the wind velocity acting on an isolated train. The method is validated against a complete train plus windshield simulation in terms of pressure distribution and aerodynamic force coefficients on the train, and flow streamlines. This approach opens to the possibility of evaluating the aerodynamic performance of a vehicle on bridges considering bridge and vehicle as separated. Wind velocity profiles measured on the bridge during a wind tunnel campaign could be used as the initial condition for numerical simulations on vehicles.
Reliability of bridges considering the effect of local scour
Authors: Flores-Vidriales D. , Gómez R. , Escobar J. Alberto
Published: October 2021

Aging infrastructure is becoming a major concern in the engineering practice, thus, there is a need for the development of a suitable reliability-based analysis of aging bridges subjected to scour hazard. This paper proposes such analysis based in a time dependent stationary deterioration process for the scour demand and a random independent variable for the bridge foundation capacity. Reliability is computed using direct integration for discrete times. Based on the results, an exponential function is proposed to estimate the decrease in reliability due to the accumulation of scour around a bridge pier through time.
Quantifying damage in the steel shims of seismic isolation rubber bearings due to support rotation
Authors: Kalfas Konstantinos N. , Mitoulis Stergios A. , Konstantinidis Dimitrios
Published: October 2021

Seismic isolation is an effective technique for mitigating the earthquake movements on important infrastructures such as bridges and hospitals. Rubber bearings are one of the most common seismic isolation devices used for the protection of critical infrastructure assets. Isolators are critical elements of an isolated structure, and as such, they should experience limited, if any, damage during earthquake shaking. Damage associated with yielding of the reinforcing steel shims in seismic isolation rubber bearings has received limited attention in the literature. This study investigates the effect of the steel reinforcement characteristics on the behavior of rubber bearings under combined axial load, shear displacement, and rotation. The potential damage of the steel shims and the rubber bearings under design-level lateral loads is investigated using a damage index, rpl, and a damage factor, Ω, respectively, with emphasis placed on the thickness of steel shims.
Dynamic properties of the isolators used in the Green Museum Library (Taiwan)
Authors: Marenda Ivan , Marioni Agostino , Dalpedri Roberto , Banfi Marco
Published: October 2021

Over the last decades seismic isolation technology has got a foothold in the structural protection increasing both the damping and the natural period of the superstructure. The curved surface sliding isolator is one of the most common devices used to aim at this goal. It features a special friction material (HIM) able to dissipate a very large amount of energy while, the recentring capacity is given by the pendulum effect. This kind of isolator has been used in the Green Museum Palace (Taiwan). The constancy of its behaviour has been investigated in ShakeLab (Italy), testing 100% of the Friction Pendulum devices in factory production control. In this paper, response data from FPC tests on seven types of Friction Pendulum devices are illustrated. These data show the constancy of the performance of the isolators subjected to design conditions. Furthermore, scale effect in dynamic properties has been studied because of different size isolators have been taken into account.
Capacity of prestressed concrete bridge decks under fatigue loading
Authors: Lantsoght Eva O. L. , van der Veen Cor , Koekkoek Rutger , Sliedrecht Henk
Published: October 2021

In The Netherlands, existing slab-between-girder bridges with prestressed girders and thin transversely prestressed concrete decks require assessment. The punching capacity was studied in a previous series of experiments, showing a higher capacity thanks to compressive membrane action in the deck. Then, concerns were raised with regard to fatigue loading. To address this, two series of large-scale experiments were carried out, varying the number of loads (single wheel print versus double wheel print), the loading sequence (constant amplitude versus variable amplitude, and different loading sequences for variable amplitude), and the distance between the prestressing ducts. An S-N curve is developed for the assessment of slab-between-girder bridges. The experiments showed that compressive membrane actions enhances the capacity of thin transversely prestressed decks subjected to fatigue loading.
Automated structural assessment of existing reinforced concrete underpasses
Authors: Jilissen Danny , Vergoossen Rob , Yang Yuguang , Lantsoght Eva
Published: October 2021

Due to the large number of underpasses in the Netherlands that have to be assessed, a project at the Delft University of Technology in cooperation with Royal HaskoningDHV was started. Research was conducted into the automation of the structural assessment of existing reinforced concrete underpasses in the Netherlands. The developed Automated Structural Assessment Tool (ASA Tool) consists of an analytical model and a 2.5D FEM model. The analytical model uses traffic load distribution following the Guyon-Massonnet-Bares method for bending and a method based on fib Model Code 2010 for shear. The script-based 2.5D FEM model uses 2D shell elements and performs a linear elastic analysis. The input and output can be linked to a database for assessment of large batches. Sensitivity analyses showed that in-plane load distribution following fib Model Code 2010 combined with vertical load distribution according to EN 1991-2:2003 results in underestimated shear forces.
Study on temperature field effects on RC high-pier bridge
Authors: Wang Zhongjie , Zhang Shaoqiang , Ou Yangxun , Zhong Gaojie , Wang Ao , Zhang Zongkai , Sun Limin
Published: October 2021

Temperature is one of the essential factors that cause dynamic characteristics changes in concrete bridges. However, the study of temperature-induced structural frequency changes relies on a large number of measured data to establish a frequency-temperature mathematical model. The selection of temperature variables is arbitrary. This paper takes a concrete high-pier rigid-framed bridge under construction in China as the research object. Based on the continuous 120-day measured weather data at the bridge site, the finite element method (FEM) is used to simulate the bridge's temperature and frequency history without considering the crack and other damage conditions. A regression analysis model of frequency and temperature variables was established. The study found that the selection of temperature variables and mathematical models influences the frequency-temperature mathematical relationship; for high-pier bridges. Establishing a multiple linear regression model with air temperature and point temperature of the main girder and piers as variables can obtain an ideal fitting result.
A fiber optics enriched Digital Twin for assessment of reinforced concrete structures
Authors: Berrocal Carlos G. , Fernandez Ignasi , Rempling Rasmus
Published: October 2021

This paper presents the results of SensIT, an ongoing research initiative at Chalmers University of Technology aimed at developing a digital twin concept to improve the asset management strategies of reinforced concrete infrastructure. The developed concept relies on data collected from distributed optical fiber sensors (DOFS), which are then analysed to extract relevant features, such as deflections and crack widths, that can be used as indicators of the structural performance. Thereafter, intuitive contour plots are generated to deliver critical information about the element’s structural condition in a clear and straightforward manner. Last, both raw and analysed data are integrated into a collaborative web application where information can be readily accessed, and results can be visualized directly onto a 3D model of the element. The concept has been tested on a large-scale reinforced concrete beam subjected to flexural loading in laboratory conditions.
Benchmark model updating for cable stayed bridges
Authors: Lai Minghui , Ma Haiying , Sun Pingkuan , Turmo José
Published: October 2021

The use of benchmark model aims to establish a model with sufficient accuracy to reflect structure performance. Its purpose is seeking differences through repeated studying on problems using common FE model. In the paper, a novel approach is proposed for the benchmark model updating of a cable stayed bridge. It is based on the interaction of numerical analysis program and FE analysis program with updating model parameters from loop iteration operation. Shell elements and beam elements are both used, and the natural vibration frequencies and mode shapes from plate-shell element model are determined. These are used to modify the parameters used in a spine-beam element model, and to simplify a complicated FE model as a benchmark model. The genetic algorithm (GA) is introduced to complete the calculation process of loop iteration. Finally, an updated benchmark model is proposed for cable stayed bridges.
Application of close range photogrammetry in structural health monitoring by processing generated point cloud datasets
Authors: Mirzazade Ali , Popescu Cosmin , Blanksvärd Thomas , Täljsten Björn
Published: October 2021

In bridge inspection, vertical displacement is a relevant parameter for both short and long-term health monitoring. Assessing change in deflections could also simplify the assessment work for inspectors. Recent developments in digital camera technology and photogrammetry software enables point cloud with colour information (RGB values) to be generated. Thus, close range photogrammetry offers the potential of monitoring big and small-scale damages by point clouds. The current paper aims to monitor geometrical deviations in Pahtajokk Bridge, Northern Sweden, using an optical data acquisition technique. The bridge in this study is scanned two times by almost one year a part. After point cloud generation the datasets were compared to detect geometrical deviations. First scanning was carried out by both close range photogrammetry (CRP) and terrestrial laser scanning (TLS), while second scanning was performed by CRP only. Analyzing the results has shown the potential of CRP in bridge inspection.
A camera calibration method for bridge live load identification using plane marks on the pavement
Authors: Ai Zubin , Hou Shengjun , Jiang Chuanbin , Jia Shuaidong , Liu Xinhong , Xia Ye
Published: October 2021

Computer vision has become an effective way to collect the information of traffic load, which is crucial for bridge statistical analysis, safety evaluation, and maintenance strategies. To obtain the information of vehicles such as position and wheelbase, the location and orientation of the camera should be calibrated in advance, but the calibration needs measurement and sometimes is difficult to implement because of heavy traffic flow. Therefore, this paper proposes a camera calibration method using plane marks on the pavement without measurement. The plane marks are designed to be convenient and economical for construction so any bridge or road with a potential demand of vehicle monitoring can consider to prepare such marks on the pavement. The feasibility of the proposed method is verified through computer simulation and a model test.
Bayesian model updating of a large-span steel tied arch bridge: an experimental study
Authors: Luo Lanxin , Zhong Huaqiang , Xia Ye , Sun Limin
Published: October 2021

In this paper, a large-span steel tied arch bridge's Bayesian FEMU is carried out based on the ambient vibration data. Firstly, the ERA method is used for modal identification. Then, the benchmark FE model of this bridge is established. Based on the sensitivity analysis, six updating parameters significantly affecting the natural frequency are selected. Subsequently, the objective function of the FEMU is established, and the DRAM algorithm is utilized to simulate the parameter samples conforming to the posterior distribution. Finally, the uncertainty analysis of the updated items is carried out. After FEMU, the results show that the model's frequency uncertainty is reduced, and the theoretical frequencies are highly consistent with the identified frequencies.
Using an ambient vibration test to identify damage in a sculpture
Authors: Caetano Elsa
Published: October 2021

This paper describes the studies conducted to assess damage in a sculpture. These include a numerical model and an ambient vibration test based on a dense mesh of points to identify the fundamental natural frequencies and the corresponding modal shapes. From the comparison between identified and calculated modal parameters, it was possible to identify a region of inflexion of curvatures of the second-order vibration modes at a particular location that was associated with a local fragility of the structure. A posterior removal of the cladding evidenced a highly degraded area at this location.
The use of SHM to monitor and evaluate bridge movements – absolute and accumulated – at the structure’s bearings and expansion joints
Authors: Meng Niculin , Richli Thomas , O’Suilleabhain Colm
Published: October 2021

The movements a bridge experiences, both absolute and accumulated over time, can significantly influence the structure’s life-cycle performance – especially as it relates to the components that facilitate these movements. Structural health monitoring (SHM) systems, with sensors placed at – or ideally, integrated in – a bridge’s bearings and expansion joints, can be used to efficiently record and evaluate these movements, facilitating continuous monitoring of the components’ and the structure’s performance over time. This can enable potential problems to be recognised at an early stage, and maintenance (e.g. replacement of “wear parts” such as sliding materials) to be optimised. The significance of the frequency at which measurements are recorded must be appreciated, as high-frequency data can capture micro-movements (e.g. due to wind or traffic) that far exceed the slow thermal movements. This paper explores this topic with reference to a number of case studies.
Denoising of structural health monitoring data: method and coding
Authors: Ni Peng , Xia Ye , Li Wanheng , Liu Hanyong , Sun Limin
Published: October 2021

Numerous denoising approaches have already been presented to handle the noise in measured data of structural health monitoring systems. However, the performances and features of these existing methods applied in real data-set are not clear enough yet, where the noise is not known in advance. Therefore, based on the measured structural response data from a tied-arch bridge in China, six common data denoising methods are selected for a comparative study. The denoising effects are evaluated based on spectrums. Conclusions on the applicable situations and robustness of involved methods are given. A corresponding program is also developed. This study can provide references for applying the denoising methods in real structural health monitoring system data-set.
Image stabilization technology for active bridge-vessel anti-collision monitoring system
Authors: Shao Zhufeng , Ma Haiying , Xia Ye , Wang Junjie
Published: October 2021

In recent years, the active anti-collision system using new technologies such as image target recognition between ship and bridge becomes a new research hotspot. Due to camera jitter, it is not easy to deeply mine the monitoring image data. This paper puts forward an anti-jitter algorithm to obtain the ship monitoring track in the sea area removing the camera jitter. It uses electronic image stabilization, sea-sky line anti jitter filtering, and other methods to process the on-site monitoring video, then compares the effect of each technique, and finally obtains high-quality ship tracking data. Through this method, a high-quality ship monitoring track in the bridge area can be obtained.
Acceleration data quality assessment for bridge structural health monitoring via statistical and deep-learning approach
Authors: Zhong Huaqiang , Sun Limin , Turmo José , Xia Ye
Published: October 2021

In recent years, the safety and comfort problems of bridges are not uncommon, and the operating conditions of in-service bridges have received widespread attention. Many large-span key bridges have installed structural health monitoring systems and collected massive amounts of data. Monitoring data is the basis of structural damage identification and performance evaluation, and it is of great significance to analyze and evaluate its quality. This paper takes the acceleration monitoring data of the main girder and arch rib of a long-span arch bridge as the research object, analyzes and summarizes the statistical characteristics of the data, summarizes 6 abnormal data conditions, and proposes a data quality evaluation method of convolutional neural network. This paper conducts frequency statistics on the acceleration vibration amplitude of the bridge in December 2018 in hours. In order to highlight the end effect of frequency statistics, the whole is amplified and used as network input for training and data quality evaluation. The results are good. It provides another new method for structural monitoring data quality evaluation and abnormal data elimination.