Repository of Faculty of Civil Engineering Osijek
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Flow through orifices
No full textOvaj završni rad bavi se istraživanjem fenomena istjecanja kapljevine kroz otvore. U teorijskom Bernoullijevu jednadžbu, Torricellijev zakon i jednadžbu kontinuiteta. U eksperimentalnom dijelu rada proveden je niz mjerenja za nepotopljeno i potopljeno istjecanje, s posebnim naglaskom na utjecaj nasadka na koeficijent istjecanja. Rezultati pokazuju da su veći gubici energije zabilježeni kod nepotopljenog istjecanja s nasadkom, što je povezano s povećanim trenjem i složenijim strujanjem unutar nasadka. Na kraju, rad zaključuje važnost prilagodbe teoretskih modela stvarnim uvjetima, kako bi se postigla točnost i efikasnost u projektiranju hidrauličkih sustava.This thesis investigates the phenomenon of liquid flow through openings. The theoretical part explains the key laws and equations that describe this process, including Bernoulli's equation, Torricelli's law, and the continuity equation. The experimental part of the study involves a series of measurements for unsubmerged and submerged flow, with a particular focus on the effect of nozzles on the discharge coefficient. The results indicate that greater energy losses occur in
unsubmerged flow with nozzles, due to increased friction and more complex flow patterns within the nozzles. Ultimately, the study emphasizes the importance of adapting theoretical models to real-world conditions to achieve accuracy and efficiency in the design of hydraulic systems
Analysis and comparison of truck-mounted concrete pumps
No full textPumpe za beton omogućuju precizno i brzo dostavljanje betona na gradilišta, čime se ubrzava proces izgradnje i smanjuje potreba za ručnim radom, s obzirom na rastuću potrebu za učinkovitijim i preciznijim rješenjima za transport betona. Pumpe za beton omogućuju prijenos betona s visokom preciznošću na različitim gradilištima, čime značajno povećavaju produktivnost i smanjuju troškove rada. U analizi i usporedbi pumpi za beton, važno je razmotriti nekoliko ključnih faktora, uključujući kapacitet pumpe, maksimalnu visinu dizanja betona, jednostavnost upravljanja, troškove održavanja i pouzdanost opreme. Usporedba različitih modela pumpi otkriva razlike u performansama koje su često povezane s proizvođačem, tipom pumpe, te specifičnim tehničkim karakteristikama, koje mogu značajno utjecati na odabir prave pumpe za specifičan projekt. Veći kapacitet i veća brzina pumpanja mogu biti presudni u velikim projektima gdje je potrebno dostaviti velike količine betona u kratkom vremenskom roku. S druge strane, fleksibilnost i manevarske sposobnosti manjih pumpi mogu biti ključne za projekte s ograničenim pristupom. Također, značajna je razlika u cijeni između različitih modela, što često osim o njihovim performansama ovisi i o dodatnim značajkama kao što su daljinsko upravljanje i sustavi za automatsko čišćenje. Kroz detaljnu analizu i usporedbu, moguće je odabrati kamionsku pumpu koja najbolje odgovara specifičnim potrebama gradilišta, čime se osigurava učinkovitost i kvaliteta građevinskih radova.Concrete pumps enable precise and rapid delivery of concrete to construction sites, accelerating the construction process and reducing manual labour, considering the growing demand for more efficient and accurate solutions for concrete transport. Concrete pumps allow for exact concrete transfer on various construction sites, significantly increasing productivity and reducing labour costs. In the analysis and comparison of concrete pumps, it is essential to consider several critical factors, including pump capacity, maximum concrete lifting height, ease of operation, maintenance costs, and equipment reliability. Comparing different pump models reveals differences in performance that are often associated with the manufacturer, pump type, and specific technical characteristics, which can significantly influence the selection of the right pump for a particular project. For example, higher capacity and faster pumping speed can be crucial in large projects where large amounts of concrete must be delivered quickly. On the other hand, the flexibility and manoeuvrability of smaller pumps can be essential for projects with limited access. Additionally, there is a significant price difference between different models, often depending on their performance and additional features such as remote control and automatic cleaning systems. Through detailed analysis and comparison, it is possible to choose a concrete pump that best suits the specific needs of the construction site, ensuring the efficiency and quality of construction work
Bearing capacity of shallow foundations
No full textU ovom završnom radu opisana je problematika nosivost tla ispod plitkih temelja, različiti pristupi proračunu te analiza utjecaja različitih čimbenika na nosivost temeljnog tla. Prikazano je kako rješavamo ovaj problem prema Eurocode-u 7, što on predstavlja i kako se vrše analize nosivosti prema istom. U daljnjem tekstu opisano je kako možemo utjecati na poboljšanje same nosivosti tla.
U nastavku se upoznajemo s terenskim ispitivanjima tla te postupcima određivanja nosivosti tla na terenu. Također, prikazan je i jedan proračunski primjer kojim dokazujemo sve prethodno teoretski napisano.This thesis describes the issue of bearing capacity of the soil under shallow foundations, different approaches to calculation and analysis of the influence of various factors on the bearing capacity of the foundation soil. It is shown how we solve this problem according to Eurocod 7, what it represents and how the test analyzes are performed according to the same. The following text describes how we can influence the improvement of the soil's bearing capacity. In the following, we are introduced to field tests of soil and procedures for determining the bearing capacity of soil in the field. Also, a calculation example is presented, which proves everything previously written theoretically
The influence of the amount of superplasticizer on the drying shrinkage of concrete
No full textUnutar ovog rada je prikazana je upotreba superplastifikatora u betonima i njihov utjecaj na skupljanje betona sušenjem. Pojašnjen je sastav i način upotrebe navedenih materijala. U pregledu literature je predstavljena primjena i načini obrade betona koji ima značajnu ulogu u suvremenoj gradnji. Analizirano i ispitano skupljanje betona sušenjem s različitim vrstama i količinama superplastifikatora pri različitim režimima njege betona. Cilj je uočiti utjecaj superplastifikatora na skupljanje betona. Takvo skupljanje je izraženo kao ε (mm/m), a izraženo je kao prosječno skupljanje na temelju izmjerenih vrijednosti na određenim mjernim mjestima. Provedena su mjerenja skupljanja betona svakih sedam dana tijekom pedeset i šest dana. Svi betoni bili su izloženi istom režimu njege. Nakon provedenih eksperimentalnih ispitivanja provedena je analiza i interpretacija rezultata na temelju
kojih su doneseni zaključci.In this work, the use of superplasticizers in concrete and their influence on shrinkage of concrete. The composition and method of use of the mentioned materials are explained. The literature review presents the application and ways of processing concrete, which plays a significant role in modern construction. Analyzed and tested drying shrinkage of concrete with different types and amounts of superplasticizers at different concrete care regimes. The goal is to observe the influence of
superplasticizers on concrete shrinkage. Such shrinkage is expressed as ε (mm/m), and it is expressed as an average shrinkage based on the measured values at specific measuring points. Concrete shrinkage measurements were taken every seven days for fifty-six days. The concretes were cared for in the same care regime. After the experimental tests, an analysis and interpretation of the results were carried out, based on which the conclusions were drawn
Calculation of inner forces for a three-hinged frame canopy and projections of displacements
No full textU prvom dijelu zadatka potrebno je izračunati unutarnje sile u zadanom presjeku uslijed djelovanja zadanog opterećenja na trozglobni okvir te nacrtati dijagrame unutarnjih sila. Za proračun unutarnjih sila u presjeku n-n upotrebljavaju se dvije različite metode koje daju iste rezultate. Koristi se klasični postupak pomoću uvjeta ravnoteže te metoda virtualnog rada. Posebno se proračunavaju uzdužne sile, vertikalne sile i momenti savijanja. Potrebno je nacrtati dijagrame unutarnjih sila zadane konstrukcije na način da se na svakom mjestu opterećenja proračunavaju unutarnje sile klasičnim postupkom iz uvjeta ravnoteže.
U drugom dijelu zadatka potrebno je za zadani mehanizam odrediti kuteve zaokreta zadanih tijela, te pomake zadanih točaka. Zadatak je potrebno riješiti pomoću plana pomaka, tj. pomoću određivanja polova pomaka, crtanja poznatih kinematskih veličina jednog tijela, konstruiranja plana pomaka preostalog dijela mehanizma i određivanje kinematskih veličina svih tijela iz
geometrijskih uvjeta. Dobivene rezultate potrebno je kontrolirati pomoću vektorskog računa.The first part of the task is to calculate inner forces within given section due to impact of given construction on three-hinged frame and to draw diagrams of the inner forces for the given construction. For calculation of inner forces in the n-n section there are used two different methods which gives the same results. It is used the static equilibrium condition and the method
of virtual work. Longitudinal forces, vertical forces and bending moments are calculated separately. In order to draw the diagrams of inner forces, they are calculated using the static equilibrium condition for every point of the load.The second part of the task is to determine the angles of rotation of the given bodies and the discplacements of the given points of a three-hinged frame. The task is solved by using displacement diagrams, i.e by determing displacement, drawing the known kinematic sizes of a body, constructing the displacement diagrams of the remaining part of the mechanism and determing kinematic sizes of all bodies from the geometrical conditions. The results are controlled by using the vector calculus
Bearing capacity and settlements calculations of a foundation on a slope
No full textMehanika tla bavi se proučavanjem mehaničkih svojstava tla s ciljem određivanja njihovih utjecaja na stabilnost i uporabivost geotehničkih konstrukcija. Za utvrđivanje svojstava tla mogu se primijeniti analitički i eksperimentalni postupci. Dio mehanike tla bavi se proučavanjem utjecaja koji temelji mogu imati na tlo. Temelj je neizostavni dio svake građevine. Ukoliko se temelj nalazi u blizini površine govorimo o plitkim temeljima. U ovom radu govorit ćemo o nosivosti tla ispod plitkih temelja, vrstama proračuna koje se mogu primijeniti za proračun nosivosti te slijeganju tla ispod plitkih temelja. Jedan od problema u mehanici tla predstavlja određivanje stabilnosti kosina te temeljenje na kosinama. Za određivanje nosivosti tla na kosinama koriste se analitičke metoda proračuna kao i računalni programi. U okviru rada opisani su ovi proračuni, a provedene su i analize nosivosti temelja na kosini za različite uvjete primjenom analitičkih i numeričkih proračuna
Analysis of precipitation and water level at Osijek station
No full textU ovom završnome radu provedena je analiza oborina na meteorološkoj postaji Osijek i vodostaja na rijeci Dravi na hidrološkoj postaji Osijek. Navedene su glavne značajke rijeke Drave te je opisana klasifikacija oborina i instrumenti za mjerenje. Prikazana je hidrološka analiza oborina na mjernoj postaji Osijek u razdoblju od 2012. do 2021. godine. Nadalje je obrađen teorijski dio za vodostaje te analiza vodostaja na mjernoj postaji Osijek. Podaci za oborine i vodostaje su preuzeti sa državnog hidrometeorološkog zavoda (DHMZ). Na završetku je prikazan utjecaj oborina na visinu vodostaja pomoću korelacijskog koeficijenta.In this thesis, an analysis of precipitation at the Osijek meteorological station and the water level on the Drava River at the Osijek hydrological station is presented. The main features of the Drava River are listed and the classification of precipitation with measurement instruments are described. The hydrological analysis of precipitation at the measuring station Osijek in the period from 2012 to 2021 is presented. Furthermore, the theoretical part and the analysis of water levels at the measuring station Osijek were processed. Data for precipitation and water level were taken from State Hydrometeorological Institute (Državni hidrometeorološki zavod). In conclusion, the impact of precipitation on the height of the water level is shown using the correlation coefficient
Construction site layout
No full textU završnom radu obrađena je shema uređenja gradilišta i njezini elementi. Shema je grafički prikaz koji prikazuje raspored i organizaciju različitih elemenata na gradilištu. Služi kao vodič za izvođenje građevinskih radova i obuhvaća ključne aspekte kao što su raspored objekata, pristupne ceste, sigurnosne zone, infrastruktura i skladištenje materijala. Shema uređenja gradilišta pomaže u planiranju i organizaciji radova, osigurava sigurnost i učinkovitost te olakšava komunikaciju među članovima tima.In the final paper, the arrangement scheme of the construction site and its elements were processed. A scheme is a graphic representation that shows the layout and organization of various elements on a construction site. It serves as a guide for the execution of construction works and covers key aspects such as layout of facilities, access roads, safety zones, infrastructure, and storage of materials. The layout scheme of the construction site helps in planning and organizing the works, ensures safety and efficiency, and facilitates communication between team members
Prediction of the Characteristics of Concrete Containing Crushed Brick Aggregate
No full textThe construction industry faces the challenge of conserving natural resources while maintaining environmental sustainability. This study investigates the feasibility of using recycled materials, particularly crushed clay bricks, as replacements for conventional aggregates in concrete. The research aims to optimize the performance of both single regression tree models and ensembles of regression trees in predicting concrete properties. The study focuses on optimizing key parameters like the minimum leaf size in the models. By testing various minimum leaf sizes and ensemble methods such as Random Forest and TreeBagger, the study evaluates metrics including Root Mean Squared Error (RMSE), Mean Absolute Error (MAE), Mean Absolute Percentage Error (MAPE), and the coefficient of determination (R2). The analysis indicates that the most influential factors on concrete characteristics are the concrete’s age, the amount of superplasticizer used, and the size of crushed brick particles exceeding 4 mm. Additionally, the water-to-cement ratio significantly impacts the predictions. The regression tree models showed optimal performance with a minimum leaf size, achieving an RMSE of 4.00, an MAE of 2.95, an MAPE of 0.10, and an R2 of 0.96
Earthquake assessment of saint Saviour Church in Dubrovnik
No full textStari grad Dubrovnik smješten na jugu Hrvatske dio je bogate kulturne baštine Republike Hrvatske. Unatoč brojnim potresima i požarima koji su uništili dio povijesnih građevina, Dubrovnik se i danas prepoznaje kao jedan od najljepših i jedinstvenih gradova na Mediteranu. Nakon potresa 1979. godine s epicentrom u Crnoj Gori, stara jezgra Dubrovnika uvrštena je na UNESCO-v Popis svjetske baštine kako bi se povećala pozornost na obnovu i očuvanje kulturne-povijesne baštine. Crkva svetog Spasa, smještena u staroj gradskoj jezgri Dubrovnika, izgrađena je nakon potresa 1520. godine u znak zahvale što nije došlo do potpunog razaranja grada. Cilj diplomskog rada je potresna analiza Crkve svetog Spasa nakon potresa s epicentrom u Crnoj Gori 1979. godine i elastičnih spektara odziva povratnih perioda od 95, 225 i 475 godina. Za provođenje potresnog ocjenjivanjanja crkve, izrađen je prostorni proračunski model u računalnom programu SCIA Engineer. Dobiveni periodi vibracija proračunskog modela poklapaju se s vibracijama dobivenih in-situ ispitivanjima istraživačkog projekta IP-2020- 02-3531 „Procjena seizmičkog rizika građevina kulturne baštine u Hrvatskoj – SeisRICHerCRO” Hrvatske zaklade za znanost. Ovaj rad može se smatrati kao polazište za složenije proračune i analize Crkve svetog Spasa u Dubrovniku.The Old City of Dubrovnik, located in the south of Croatia, is part of the rich cultural heritage of the Republic of Croatia. Despite numerous earthquakes and fires that destroyed part of the historical buildings, Dubrovnik is still recognized today as one of the most beautiful and unique cities in the Mediterranean. After the 1979 earthquake with the epicenter in Montenegro, the Old City of Dubrovnik was included in the UNESCO World Heritage List in order to increase attention to the restoration and preservation of the cultural-historical heritage. The Church of the Holy Savior, located in the old city center of Dubrovnik, was built after the earthquake in 1520 as a sign of gratitude that the city was not completely destroyed. The aim of the diploma thesis is the seismic analysis of the Church of the Holy Savior after the earthquake with the epicenter in Montenegro in 1979 and the elastic response spectra of return periods of 95, 225 and 475 years. To carry out seismic evaluation of the church, a spatial structural model was created in the computer program SCIA Engineer. The obtained vibration periods of the structural model coincide with the vibrations obtained from in-situ tests of the research project IP-2020-02-3531 "Assessment of the seismic risk of cultural heritage buildings in Croatia - SeisRICHerCRO" of the Croatian Science Foundation. This work can be considered as a starting point for more complex calculations and analyzes of the Church of the Holy Savior in Dubrovnik