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Experimental characterization of jet grout using digital image correlation technique
No full textJet grouting is a well-established and versatile ground improvement technique widely used to enhance the mechanical performance of weak or heterogeneous soils. It has proven effective across diverse soil conditions, motivating further experimental and parametric characterization. While sustainability goals have encouraged the use of eco-friendly additives, cement-based mixtures remain predominant due to their adaptability and reliable performance. Despite its widespread application, the mechanical behavior and failure mechanisms of in-situ jet grout columns have received limited experimental investigation, especially under uniaxial loading. This study explores the potential of Digital Image Correlation (DIC) as an advanced, non-contact optical technique for measurement of full-field displacements and strains on the surface of an object and fracture behavior during mechanical testing. Although DIC is more or less regularly used for concrete, natural rock, and composites, its application to jet grouting materials is rarely reported. Core samples were obtained from an active construction site, specifically from a coarse-grained soil layer, and were subjected to laboratory testing to evaluate key mechanical parameters such as: compressive strength, stiffness, and stiffness-to-strength ratios. The experimental approach aims to assess material variability and evaluate the relevance of standard modulus-based design parameters. The findings contribute to a deeper understanding of jet grout behavior and demonstrate the value of DIC as a complementary method for the performance assessment and design verification of jet grouted systems in coarse-grained soils
The 2022 drought needs to be a turning point for European drought risk management
No full textThe 2022 European drought has underscored critical deficiencies in European water management. This paper explores these shortcomings and suggests a way forward for European drought risk management. In particular,
we focus on four key aspects: the increasing drought risk,
its spatial and temporal impacts, current management approaches, and how these differ across Europe. We base our
findings on a continent-wide survey of water managers involved in responding to the 2022 drought. The survey collected 481 responses from 30 European countries and contained 19 questions on perceived sectorial impacts and the
drought risk management practices implemented by the respondents’ organizations. Information from the survey was
supported with climate-related data on drought severity as
quantified by the Standardised Precipitation Evapotranspiration Index, to offer a comprehensive overview of how extreme historical droughts are managed across Europe. Our
findings reveal a consensus on the growing risk of drought,
driven by droughts’ rising frequency and intensity. While
the 2022 event affected most of the continent, our findings
show significant regional disparities in management capacity. In many countries – particularly those with agriculturedominated economies – drought responses remain short-term
and reactive, often leading to potentially maladaptive practices. Despite these challenges, we also observe a positive
shift, with organizations showing increased awareness and
preparedness. Hence, the lessons learnt from the 2022 event
may provide an ideal opportunity to mainstream Europeanwide drought risk management. To seize this opportunity,
we advocate for a European Drought Directive, to harmonize and enforce risk management policies across the continent. This directive should promote a systemic, integrated,
and long-term risk management perspective. It should also
set clear guidelines at the national and sub-national level,
and for cross-boundary drought collaboration. This study
and its companion paper, “From Crisis to Capacity: Institutional Preparedness and Response During the 2022 European Drought”, result from work carried out by the Drought
in the Anthropocene network, an initiative of the International Association of Hydrological Sciences (IAHS).This article is part of the special issue ”Drought, society, and ecosystems (NHESS/BG/GC/HESS inter-journal SI)”. It is not associated with a conference
Critical temperature of FGM plates resting on elastic foundations using layerwise finite element
No full textIt is known that many civil engineering structures are made from concrete, such as smart pavements, railways, bridges and building. Many of them may be exposed to severe environmental conditions during serviceability limit state. The temperature effects, as one of the environmental conditions, is often the cause of damage to concrete plates. By incorporated different agents and fibers to concrete mixture, the concrete structures may be monitored, controlled and healed against temperature damage. The material behavior of such mixture may generally be described by functionally graded materials (FGM) material models. To the author’s best knowledge, there has been no study in the literature regarding thermal buckling of FGM plates resting on elastic foundations using LW theory of Reddy. Therefore, in this study the thermal buckling analysis of functionally graded plates resting on elastic foundation is modelled using one–parameter Winkler’s and two–parameter Pasternak’s model. The mathematical model, based on Layer wise theory of Reddy, assumes layer wise variation of in plane displacements and constant transverse displacement through the thickness, non–linear strain displacement relations (in von Karman sense) and isotropic nonhomogeneous thermo–mechanical material properties. The material properties of FGM plates are assumed to be constant in xy–plane and vary through the thickness by a power law function in terms of the volume fraction of the constituents. The principle of virtual displacement (PVD) is used to derive the weak form of linearized buckling problem. The weak form is discretized using 2D nine–node Lagrangian isoperimetric finite element. The original MATLAB computer program is coded for finite element solution. The influence of different parameters, such as temperature distribution, side–to–thickness ratio b/h, aspect ratio a/b, power–low index n and elastic foundation parameters (kw, ks), are analyzed. The accuracy of the numerical model is verified by comparison with the available results from the literature and may be used in the design of smart concrete structures
SMART-PSH methodology as a tool for spatial planning and ranking of potential pumped storage hydropower systems in Serbia
No full textUbrzani razvoj obnovljivih izvora energije, pre svega solarnih- i vetroelektrana, uslovio je potrebu za razvojem efikasnih rešenja za skladištenje energije i bilansiranje elektroenergetskog sistema. Reverzibilne hidroelektrane (RHE) i pumpno-akumulaciona postrojenja (PAP) predstavljaju najpouzdaniji i najefikasniji vid skladištenja energije u savremenim elektroenergetskim sistemima, sa dominantnim udelom u ukupnim svetskim kapacitetima za skladištenje energije. U cilju identifikacije najpogodnijih lokacija za razvoj ovih sistema u Republici Srbiji razvijena je SMART-PSH (Site Mapping and Ranking Technique for Pumped Storage Hydropower plants) metodologija, koja objedinjuje GIS analize, ekspertsku procenu i višekriterijumsko rangiranje. Ovaj pristup omogućava automatizovano i sistematično pretraživanje prostora, uz uvažavanje širokog spektra kriterijuma – od topografskih, hidroloških i geoloških, do ekoloških, infrastrukturnih i socio-ekonomskih. Rezultati primene SMART-PSH metodologije omogućavaju efikasno prepoznavanje i vrednovanje potencijalnih lokacija za izgradnju RHE i PAP sistema, pružajući osnovu za strateško planiranje i dalji razvoj elektroenergetskog i vodoprivrednog sektora Republike Srbije u skladu sa ciljevima energetske tranzicije i povećanja učešća obnovljivih izvora energije.Development of renewable energy sources, primarily solar and wind power plants, has intensified the demand for robust energy storage solutions and reliable power system balancing mechanisms. Pumped storage hydropower plants (PSH) and pumped storage facilities remain the most mature, dependable, and efficient large-scale energy storage technologies within contemporary power systems, holding a dominant share in global energy storage capacities. To identify the most suitable locations for the development of these systems in the Republic of Serbia, the SMART-PSH (Site Mapping and Ranking Technique for Pumped Storage Hydropower plants) methodology has been developed. This methodology integrates GIS analyses, expert evaluation, and multi-criteria ranking. The approach enables automated and systematic spatial screening while considering a wide range of criteria—from topographic, hydrological, and geological conditions to ecological, infrastructural, and socio-economic factors. The results of applying the SMART-PSH methodology allow for the efficient identification and assessment of potential sites for PSH development, providing a foundation for strategic planning and further advancement of the energy and water resources sectors in the Republic of Serbia, in line with the goals of the energy transition and the increased share of renewable energy sources
A review of existing seismic vulnerability functions in the Balkan region
No full textThis paper provides detail investigation of the methodologies developed for seismic vulnerability assessment in the area. Empirical, analytical, and hybrid approaches that have been regionally developed and applied are summarized and their similarities and differences are discussed. Having in mind the parallels in existing structural archetypes in the region (N. Macedonia, Serbia, Bosnia and Herzegovina, Croatia, Greece), the investigation focuses on the most common types: masonry and reinforced concrete structures. A reliable assessment of seismic hazard is essential for effective vulnerability evaluation, and the relevant published methodologies are also summarized. Moreover, the developed risk assessment methodologies are also summarized and discussed
Istorijski prikazi građevinskih radova na Hramovnoj gori u Jerusalimu u periodu prve polovine 4. do prve polovine 8. veka
No full textХрамовна гора у Јерусалиму представља једно
од најважнијих места у историји монотеистичких религија. За
јудеизам je најзначајније место порушеног Храма, где је
приношена старозаветна жртва Богу. За хришћане je тo место
у непосредној близини јеврејског Храма, у Преторијуму, или
Антонијевом утврђењу, где се одржало суђење Господу Исусу
Христу. За ислам, треће место по важности, после Меке и
Медине, je место где је Мухамед, по учењу Курана, слетео
током свог ноћног путовања. Све ово условило је различите
грађевинске подухвате на овом месту, нарочито у периоду од
установљења хришћанства, као званичне религије Римског
царства, до освајања Јерусалима од стране Арапа, као носиоца
нове вере - ислама. Аутор у свом раду покушава да изврши
хронолошку реконструкцију изградње одређених цркава и
манастира, у поменутом периоду, на подручију Храмовне горе
и у њеној непосредној близини, као и каснију, највероватнију,
промену намена ових објеката, по освајању Јерусалима од
стране Арапа
Metodologija SMART-PSH kao alat za izbor lokacije i rangiranje potencijalnih RHE Sistema u Srbiji
No full textUbrzani razvoj obnovljivih izvora energije, pre svega
solarnih- i vetroelektrana, uslovio je potrebu za
razvojem efikasnih rešenja za skladištenje energije i
bilansiranje elektroenergetskog sistema. Reverzibilne
hidroelektrane (RHE) i pumpno-akumulaciona
postrojenja (PAP) predstavljaju najpouzdaniji i
najefikasniji vid skladištenja energije u savremenim
elektroenergetskim sistemima, sa dominantnim udelom
u ukupnim svetskim kapacitetima za skladištenje
energije. U cilju identifikacije najpogodnijih lokacija za
razvoj ovih sistema u Republici Srbiji razvijena je
SMART-PSH (Site Mapping and Ranking Technique
for Pumped Storage Hydropower plants) metodologija,
koja objedinjuje GIS analize, ekspertsku procenu i
višekriterijumsko rangiranje. Ovaj pristup omogućava
automatizovano i sistematično pretraživanje prostora, uz
uvažavanje širokog spektra kriterijuma – od
topografskih, hidroloških i geoloških, do ekoloških,
infrastrukturnih i socio-ekonomskih. Rezultati primene
SMART-PSH metodologije omogućavaju efikasno
prepoznavanje i vrednovanje potencijalnih lokacija za
izgradnju RHE i PAP sistema, pružajući osnovu za
strateško planiranje i dalji razvoj elektroenergetskog i
vodoprivrednog sektora Republike Srbije u skladu sa
ciljevima energetske tranzicije i povećanja učešća
obnovljivih izvora energije
Kriterijumi za primenu hibridnog modela 3D katastra u Srbiji
Full text link3D katastar kao savremeni pristup razvoju katastarskog informacionog sistema donosi mnoge prednosti i rešava poteškoće koje ima sadašnji katastarski sistem kada je reč o upisu i vizualizaciji 3D kompleksnih situacija. Shodno tome, prelazak na 3D katastarski sistem zahteva znatno više resursa jer je potrebno podatke prikupiti, obraditi, skladištiti, održavati i distribuirati u 3 dimenzije. Da bi se otvorio pristupačniji put ka implementaciji 3D katastra jedan od ponuđenih pristupa predstavlja hibridni model. To podrazumeva da se sadašnji 2D katastarski podaci koriste u što većoj meri a da na onim lokacija na kojima nije moguće nedvosmisleno predstaviti nepokretnosti i granice poseda koristi 3D pristup. U ovom radu obrađeni su i predstavljeni osnovni kriterijumi koji definišu kada je neophodan 3D pristupu u okviru hibridnog modela i shodno tome data osnovna procena odnosa 2D i 3D pristupa na test primeru
Sewer discharge data fusion for reduction of in-situ measurement uncertainty
No full textHighlights
• Adverse flow conditions can significantly affect the uncertainty of sewer discharge measurements.
• Reference method is used for quantifying the dynamics of the in-situ measurement uncertainty.
• The combination of multiple measurement methods allows for higher discharge data quality
Preparing for revitalization of the turbines of the HE Đerdap 2: Measurement of velocity distribution at turbine inlets
Full text linkKontinualno merenje protoka na brojnim turbinama hidroelektrana se standardno radi nekom od relativnih metoda (na primer Winter-Kennedy). Umesto da se meri složeno polje brzina u jednoj proticajnoj ravni i da se njenom integracijom dobije protok, meri se samo jedna karakteristična veličina a na fizičkom modelu se odrede parametri preslikavanja vrednosti te veličine u trenutni protok. Najčešće se koristi Winter-Kennedy metoda gde se merenjem razlike pritisaka dobija relativna (indeksna) vrednost protoka. Merna nesigurnost tako određenog protoka je znatno veća od nesigurnosti merenja ostalih relevantnih veličina za određivanje optimalnih radnih uslova turbine. Da bi se smanjila merna nesigurnost, potrebno je „apsolutnim merenjima“ celog polja brzina odrediti trenutni protok i preračunati, u realnim uslovima, korekcije indeksne metode. To se posebno odnosi na hidroelektrane čija dispozicija nije „idealna“ kao što je bila na fizičkom modelu, kao što je HE „Đerdap 2“ sa poznatim problemom „kosog dostrujavanja“. Sa ciljem bolje procene hidrauličke efikasnosti turbina i prikupljanja podataka o realnim uslovima rada turbina i ulazne rešetke, a zbog planiranih radova na revitalizaciji, projektovan je i primenjen inovativni sistem za apsolutno merenje protoka koji je prikazan u ovom radu. Na pokretni ram, pozicioniran na ulazu u turbinu uzvodno od grube rešetke, postavljeno je 15 elektromagnetnih (EM) senzora u jednoj horizontalnoj ravni, zajedno sa dva redudantna akustična Doppler senzora. Svaki od senzora meri sve tri komponente brzina. Ram se podiže duž cele visine proticajnog preseka snimajući celo polje brzina. Položaj rama se prati pomoću dva enkodera, dok se dva senzora pritiska koriste za merenje dubine vode. Merenja su sinhronizovana sa lokalnim SCADA sistemom odakle se preuzimaju podaci o radu turbine. Uvažavajući specifičnosti mernog sistema, novorazvijenih EM sondi i postojećih hidrauličkih uslova, razvijena je adekvatna procedura za procenu nesigurnosti izmerenog protoka. U ovom radu je prikazana merna metoda i dati su neki rezultati merenja na agregatima HE „Đerdap 2“.The continuous flow measurement on hydroelectric turbine units is conventionally carried out using the relative methods (mostly Winter-Kennedy), where the complex velocity field in flow cross section is replaced by a single measured quantity. On a physical model, mapping parameters are determined. The Winter-Kennedy method is most used, where this relative (index) flow quantity is obtained by measuring differential pressure. The measurement uncertainty of the determined flow using this method is usually significantly higher than the uncertainty of other relevant quantities for determining the optimal turbine operating conditions. To reduce the flow uncertainty, it is necessary to perform "absolute measurements" of the entire velocity field and determine the necessary corrections to the index method under real operating conditions. This is especially true for plants where disposition is different from one used on physical model, which is the case of “Đerdap 2” and recognized problem of skewed inflow. With the aim of better assessing the hydraulic efficiency of turbines and to collect data on the actual operating velocity distribution in the inlet section in front of trash-rack needed for planned revitalization works, an innovative system for absolute flow measurement has been designed and implemented. The moving frame was designed and installed at the turbine inlet, upstream from the trash-rack. The 15 electromagnetic (EM) sensors and two redundant acoustic Doppler sensors were installed on horizontal bar. Each sensor measures all three velocity components. The frame moves by lifting along the entire height of the flow section, allowing the entire velocity field to be scanned. The position of the frame is tracked by two encoders, while two pressure sensors are used to measure the water depth. Measurements are synchronized with the local SCADA system, so appropriate turbine operation data are also used. Considering the specificities of the measurement system itself with newly developed EM sensors, as well as hydraulic conditions, an adequate procedure has been developed to assess the uncertainty of the measured flow. This paper presents the measurement method and provides some measurement results on the units of the “Đerdap 2” hydroelectric power plant