Procter & Gamble (United Kingdom)
GraFar - Repository of the Faculty of Civil EngineeringNot a member yet
3934 research outputs found
Sort by
Analiza osetljivosti rezultata proračuna šteta od poplava na promenu parametara računskog modela – Primer sliva reke Tamnave
No full textU radu se analizira računski model za procenu šteta od poplava primenjen na sliv reke Tamnave. Modelom se uzimaju u obzir četiri recepijenta rizika: stanovništvo, građevisnki objekti, poljoprivredni usevi i saobraćajnice. Za sve četiri kategorije razvijen je računski postupak koji je implementiran u programskom paketu QGIS. Proračun šteta se zasniva na primeni globalnih funkcija šteta koje definišu zavisnost novčanim vrednostima izraženih šteta od najvećeg nivoa slobodne površine vode za vreme poplavnog događaja. Pored prostornog rasporeda najvećih nivoa i oblika funkcija šteta, pri korišćenju modela neophodno je definisati i način za prostornu diskretizaciju oblasti od interesa. Osnovni cilj ovog rada jeste da se pokaže, kako na izračunate štete mogu uticati neizvesnosti u pogledu definisanja vrednosti parametara modela. Tako će se u radu dati osvrt na uticaj hidrološki i hidrauličkih analiza za određivanje merodavnih nivoa odnosno uticaj različitih načina prostorne diksretizacije na
rezultate proračuna šteta
High-Resolution UAV-based Photogrammetry for 3D Modelling and Monitoring Changes of Earth Pillars: Case Study Devil’s Town – Project Demonitor
No full textIn the project “Devil`s town Erosion MONITORing - DEMONITOR,” accessible earth pillars in the Devil`s town area will be monitored for two years using a variety of non-invasive techniques. Photogrammetric imaging with unmanned aerial vehicle (UAV) as a platform showed a great potential for 3D modeling of this site, monitoring significant changes of earth pillars and identification of rockfall occurence. In this study, it was demonstrated that manual free-flight UAV photogrammetry outperformed automatic flight missions made with vertical imagery from predefined flight plans in terms of higher level of detail on 3D model. For the period of 6 years of UAV photogrammetry monitoring it was possible to identify rockfall from the top of certain earth pillars and the complete collapse of one earth pillar
Hidraulički proračun mreža pod pritiskom primenom TRIBAL-ΔQ metode u uslovima potrošnje koja zavisi od pritiska
No full textHidraulički proračun u mrežama pod pritiskom se najčešće sprovodi pod pretpostavkom fiksne čvorne potrošnje koja ne zavisi od pritiska, u literaturi pristup poznat kao DDA (eng. Demand Driven Approach). Ova pretpostavka je opravdana ukoliko je sistem u mogućnosti da u svakom trenutku zadovolji minimalne pritiske pri kojima se ta čvorna potrošnja može i ostvariti (npr. prilikom dimenzionisanja sistema). U određenim slučajevima, kao što su pucanja cevi ili povećana potrošnja vode u sistemu, doći će očekivano do pada pritiska u mreži ispod minimalnih što posledično uzrokuje nemogućnost sistema da zadovolji fiksne čvorne potrošnje. U ovim slučajevima upotreba DDA pristupa rešavanju hidraulike sistema nije opravdana jer neće rezultovati realnom procenom pritisaka i protoka u mreži, niti je moguće proceniti koji deo čvorne potrošnje se zaista može zadovoljiti. Za prevazilaženje ovog ograničenja DDA pristupa, u proračun se mora uvesti funkcionalna zavisnost potrošnje od pritiska. Ovaj pristup, poznat kao PDA (eng. Pressure Driven Approach) u obzir uzima smanjenje čvorne potrošnje sa smanjenjem pritiska u čvoru. U ovom radu je PDA pristup implementiran u originalnu TRIBAL-ΔQ metodu za proračun mreža pod pritiskom, koja koristi formulaciju metode prstenova za rešavanje osnovnih jednačina koje opisuju tečenje u mrežama pod pritiskom. Validacija rezultata proračuna unapređene TRIBAL-ΔQ metode je izvršena poređenjem sa referentnim EPANET 2.2 softverom, zasnovanim na formulaciji metode čvorova, koji je u praksi prihvaćen kao standard za hidraulički proračun mreža pod pritiskom. Metoda je testirana na nekoliko mreža različite složenosti i preliminarni rezultati sa analizom osetljivosti pokazuju da TRIBAL-ΔQ metoda u uslovima potrošnje koja zavisi od pritiska ostvaruje istu preciznost i numeričku stabilnost proračuna kao referentna metoda EPANET 2.2 softver
Comparison of the remotely sensed and hydrological model soil moisture in the Jičinka river catchment in the Czech Republic
No full textPoznavanje stanja vlažnosti zemljišta u slivu je od velike važnosti sa stanovišta korišćenja voda, zaštite od voda i zaštite voda. U ovom radu izvršeno je poređenje vlažnosti zemljišta, dobijene na osnovu satelitskih osmatranja i primenom SHETRAN hidrološkog modela, na primeru sliva reke Jičinke (75.9 km2) u Češkoj Republici. Zbog grube prostorne rezolucije podataka o vlažnosti dobijenih satelitskim osmatranjima, redukovanjem razmere satelitskih snimaka, na osnovu poznatih vodno-fizičkih svojstava zemljišta, satelitski podaci su preuređeni na veličinu „ćelije grida” SHETRAN modela. Utvrđena je dobra korelacija između podataka o vlažnosti zemljišta, dobijenih na dva različita načina. Zaključuje se da zajednička upotreba satelitskih snimaka i hidroloških modela može doprineti dobijanju pouzdanijih i preciznijih informacija o promenama vlažnosti zemljišta unutar sliva.Understanding soil moisture conditions in a watershed is of great importance in terms of water use, water related hazard mitigation and water conservation. In this study the comparison between remotely sensed soil moisture and soil moisture estimated from the SHETRAN hydrological model was performed for the Jičinka River catchment (75.9 km2) in the Czech Republic. Due to a relatively coarse spatial resolution of the satellite-derived soil moisture data, the satellite soil moisture data were downscaled to the grid cell size ofthe SHETRAN model, according to the known soil hydraulic properties within the catchment. The good correlation between the remotely sensed and hydrological model soil moisture data was obtained. It was concluded that their joint use can contribute to obtaining more reliable and more precise information about changes in soil moisture within the catchment.ORGANIZATOR KONFERENCIJE (CONFERENCE ORGANISERS):
Srpsko društvo za zaštitu voda (Beograd), uz podršku
Ministarstva nauke, tehnološkog razvoja i inovacija Republike Srbije i Inženjerske komore Srbije
Kategorija rada: domaća konferencija M6
Automated Generation of Ground Model Incorporating Soil Spatial Variability
No full textThe field of geotechnics undergoes a significant transformation in solving complex engineering
problems by adopting digital technologies and automation processes. Among many other
improvements, digital ground modelling has become state of the art when it comes to infrastructure
projects as one of the most comprehensive ways to represent geological and geotechnical conditions
of soil and rocks. It also allows for integration of digital ground models with other subsystems,
including underground infrastructure, utilities, above ground infrastructure, and construction
processes. While the domain of 2D and 3D geological modelling has advanced significantly in the
past decades, incorporating soil spatial variability, and thus assessing the underground heterogeneity
and parameter uncertainty, remains a challenge. In this regard, this paper proposes an automated
framework for generating a digital ground model based on site-specific borehole data within a
Building Information Modelling (BIM) framework. Furthermore, the digital ground model
incorporates geotechnical parameters’ spatial variability using Conditional Random Fields (CRFs).
The soil parameter variability is simulated through CRF randomization of soil strength parameters to
determine their values at the non-sampled points. Borehole-based ground modelling is conducted
using GSTools and a BIM software environment for the case study of the New Belgrade area in
Serbia. Integrating the above-mentioned data into one holistic digital ground model offers numerous
advantages and leads to more reliable probabilistic-based predictive numerical models of structures
embedded in variable strata
The characterization of waste from the desulfurization process from steel plant and its possible application in cement composite
No full textThis paper presents the results obtained after the first phase of incorporation of a waste material
from desulfurization process (W-SOx) in the production of a composite material. The possibility
of the application of W-SOx powder in cement composites was examined through preparation
of mortar samples, based on the standard cement mortar design, where cement is replaced by the
amount of 15% and 30% with the W-SOx. After curing in humid conditions for 28 days, and
then in laboratory conditions up to the age of 90 days, the samples were tested regarding their
bulk density, flexural and compressive strength and ultrasonic pulse velocity. The tests were
performed in order to understand the influence of the W-SOx powder on the microstructure and
mechanical properties of the cement-based composite. The addition of W-SOx to mortar
mixtures, led to a linear decrease in all mechanical parameters, bulk density and ultrasonic pulse
velocity. The mixture with 30% of the cement replaced with W-SOx showed a reduction in
strength of 55.8% when compared to the reference mixture at the age of 28 days. However, the
mixture containing 15% of the W-SOx powder as cement replacement showed a reduction of
strength of 14% at the age of 28 days and 16.8% at the age of 90 days, which are promising
results for its further application. After the result analysis performed in this research, the
challenge remains to develop a specifically tailored material that promotes the zero-waste
concept. The next step in the research should be to investigate the possibility of development of
ettringite or other high volume molecules containing sulphur in the mortar mixtures, through
prolonging the curing period under water for additional two months. Finally, cement composites
should be produced with the partial replacement of cement not higher than 15% in order to
investigate their properties and possibilities for their application
Sediment accumulation of Ćelije lake (1979 - 2017)
No full textKrajem 2017. godine, hidrometrijskom metodom izvršeno je snimanje poprečnih profila na teritoriji Akumulacije "Ćelije", radi utvrđivanja količine deponovanog nanosa između dve merne epohe (1979-2017.god.). Realizovana su merenja na 25 poprečnih profila, na koti 277,00 mnm, sa ukupno 3.988 stacionaža. Metodologijom proračuna količine nanosa kreiranjem digitalnog modela dna, utvrđene su kubature za svaku epohu, dok je količina nanosa izračunata iz njihove razlike. Deponovana količina nanosa na teritoriji Akumulacije "Ćelije" (do kote normalnog uspora 277,00 mnm), u eksploatacionom periodu od 38 godina, iznosi 3,3 mil/m3.The hydrometric method was used to record the cross-sectional profiles on the territory of lake „Ćelije“ accumulation at the end of the year 2017, in order to determine the amount of deposited sediment between the two measuring epochs (1979 - 2017). Measurements were carried out on 25 cross-section profiles, at ground level 277 masl, with a total of 3988 stationeries. By methodology of calculating the amount of the sediment by creating the digital model of the lake floor, the volumes for each epoch was determined, and the amount of the sediment volume is calculated from their difference. The calculated amount of sediment in the territory of the Ćelije accumulation (up to the level of normal deceleration 277,00 mnm), in the exploitation period of 38 years, is 3.3 mil/m3
A Comprehensive Analysis of Road Crashes at Characteristic Infrastructural Locations: Integrating Data, Expert Assessments, and Artificial Intelligence
No full textRoad crashes, although random events, frequently occur on roads. However, certain
characteristic infrastructural locations require detailed analysis regarding the frequency of road
crashes. This study examines the dynamics of road crashes at characteristic infrastructural loca-
tions in Serbia from 2018 to 2022, focusing on bridges, tunnels, railroad crossings, and road work
zones. Using data on road crashes from official reports, the analysis includes trends in crash rates,
fatalities, injuries, and material damage during the above-mentioned time frame. In addition to the
data analysis, 22 experts from the fields of traffic engineering ranked the mentioned characteristic
infrastructural locations in terms of road safety. The same questions were asked to six different
artificial intelligence software programs. The findings reveal significant variations in crash rates
across different infrastructures, with bridges and road work zones having the highest number of
crashes. Expert assessment is in line with the analysis of the results, while artificial intelligence
gives a completely opposite assessment
Economic assessment of nature-based solutions to reduce flood risk and enhance co-benefits
Get PDFFlooding is expected to increase due to climate change, urbanisation, and land use change. To address this issue, Nature-Based Solutions (NBSs) are often adopted as innovative and sustainable flood risk management methods. Besides the flood risk reduction benefits, NBSs offer co-benefits for the environment and society. However, these co-benefits are rarely considered in flood risk management due to the inherent complexities of incorporating them into economic assessments. This research addresses this gap by developing a comprehensive methodology that integrates the monetary analysis of co-benefits with flood risk reduction in economic assessments. In doing so, it aspires to provide a more holistic view of the impact of NBS in flood risk management. The assessment employs a framework based on life-cycle cost-benefit analysis, offering a systematic and transparent assessment of both costs and benefits over time supported by key indicators like net present value and benefit cost ratio. The methodology has been applied to the Tamnava basin in Serbia, where significant flooding occurred in 2014 and 2020. The methodology offers valuable insights for practitioners, researchers, and planners seeking to assess the co-benefits of NBS and integrate them into economic assessments. The results show that when considering flood risk reduction alone, all considered measures have higher costs than the benefits derived from avoiding flood damage. However, when incorporating co-benefits, several NBS have a net positive economic impact, including afforestation/reforestation and retention ponds with cost-benefit ratios of 3.5 and 5.6 respectively. This suggests that incorporating co-benefits into economic assessments can significantly increase the overall economic efficiency and viability of NBS
Problematika vođenja biciklističkih kretanja u gradskim uslovima
No full textStrategija unapređenja saobraćaja u gradskim uslovima, u skladu sa evropskim direktivama i principima održive urbane mobilnosti, podrazumeva između ostalog i redukciju korišćenja putničkog automobila uz istovremeno stvaranje uslova za veće i bezbednije odvijanje pešačkog i biciklističkog saobraćaja. Strategija koju je usvojio grad Beograd podrazumeva preko 100km novih biciklističkih staza u gradu Beogradu, odnosno povećanje nemotorizovanih sredstava prevoza na oko 30% u ukupnoj raspodeli. Međutim, bez obzira na preuzete obaveze strategijom, postavlja se osnovno pitanje koje sve vrste biciklističke infrastrukture postoje, koje su suštinske razlike između njih i kako uopšte projektovati biciklistička kretanja u našim urbanim sredinama. U radu će biti prikazani osnovni principi oblikovanja biciklističkih staza, traka i puteva, uz davanje konkretnih sugestija za unapređenje njihovog vođenja u gradskim uslovima, kroz primer grada Beograda