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Non-signalized crosswalks design influence on children pedestrian behavior
No full textTraffic safety of children in urban environment has been analysed because of different reasons – the main is that traffic accidents are leading cause of death among young children and that their cognitive capacities, up to certain age, do affect significantly their traffic behaviour. The field study done previously by the authors including children pedestrians (aged 6-15) in Croatia and Italy at crosswalks situated at signalized intersections pointed some common parameters influencing children traffic behaviour – age, way of walking and as infrastructural parameters green time duration, road width. In this paper the results of field study done at different types of non-signalized pedestrian crosswalks using the same methodology in two cities in Croatia with different urban environment and traffic system will be presented. The behaviour of children (more than 200 crossings) on their way to and from school was observed by video recording as well as behaviour of drivers on the crosswalk approaches using traffic counters. On in total 11 crosswalks. The aim was to establish important infrastructural parameters that influence children behaviour in conflict area of pedestrian crosswalk. In this case children traffic behaviour was analysed and compared on the basis of measured pedestrian speed in the conflict zone of crosswalks. Analysed parameters were grouped as those considering children behaviour, driver behaviour and infrastructure and traffic. Statistical analyse was done to establish correlation between children crossing speed and defined parameters and significantly important parameters were identified. Based on the established importance of certain infrastructural parameters, recommendations for adjustment of crosswalk design in order to better meet children needs, was done
Evaluating wind turbine power plant reliability through fault tree analysis
No full textThis study presents the application of the Fault Tree Analysis (FTA) method in analyzing the reliability of a wind turbine power plant. Examining all crucial system components and simulating potential failure probabilities demonstrated the system's overall reliability using two different coefficient simulations. This approach aims to identify which elements have the most significant impact on the reliability of wind turbine systems and, consequently, determine the critical points of the analyzed system. The displayed fault tree and appropriate tabular analysis present comparative analyses between these two simulations. From both case examples, it can be concluded that the system's generator plays a crucial role in influencing the overall reliability. By applying Boolean algebra and input coefficients for two cases, the values of potential wind turbine failures were obtained: in the first case, 11.7%, while in the second case, the percentage is 5.7%
Geotechnical monitoring at landslides remediation
No full textTema rada su geotehnička opažanja pri sanaciji klizišta. Kroz rad se proteže šest poglavlja usko vezanih za temu. Kako je građevinarstvo jedno od najstarijih zanimanja, kroz povijest su primjenjivane razne metode te bi bilo gotovo nemoguće spomenuti sve, stoga sam u svakom od poglavlja pokušao objasniti bit same teme, te na posljetku sve objediniti na stvarnom primjeru monitoringa i sanacije klizišta
Architecture and urban design of Gacka business zone
No full textGlavna ideja urbanističkog rješenja je stvoriti punu
dijagonalu građevina i njoj suprotstaviti protudijagonalu
trgova i zelenih površina. Puna dijagonala sastoji se od
oštrih bridova i pravih kuteva dok su trgovi i zelene
površine projektirane kao fluidne forme krugova.
Urbanističko rješenje utječe na projektiranje zgrade pa
se tako oštri bridovi unutar zgrade koriste u uredima,
dok je zelenilo, open- space uredi i kafić projektirano
kružnim formama. Zgrada koristi sistem sakupljanja
kišnice, ima solarne ćelije na južnoj fasadi, kompostere
na krovu te mnoge druge specifikacije koje je čine
zgradom gotovo nulte energije.The main idea of urban design is to create a full diagonal
of buildings and anti- diagonal with squares
and green public spaces. Buildings are
designed with sharp angles while nature and
squares are designed with round forms. The
shapes used in urban design affect on building
design. Sharp angles are used in offices while
circle forms are used in non- built parts of the
building(greenery parts, open- space offices,
bar). Building has rainwater harvesting
system, solar cells on facade, composters on
roof and many other specifications which
makes it nearly zero energy building
Ekonomski pokazatelji gubitaka vode u javnoj vodoopskrbi: studija slučaja Republika Hrvatska
No full textNagli porast stanovništva i klimatske promjene uzrok su da su gubitci vode postali glavni problem u vodoopskrbnom i distribucijskom sustavu. Posljedice velikih gubitaka vode u vodoopskrbi očituju se u ekonomskim troškovima i štetama za okoliš. Gubitci povećavaju troškove poslovanja poduzeća zaduženih za javnu vodoopskrbu. Takvo poslovanje je neekonomično, korisnici vodnih usluga plaćaju veće račune za usluge vodoopskrbe, a pitka voda, koje je sve manje na raspolaganju za ljudske potrebe, se nepotrebno uništava. U radu su kratko prezentirane metode za pronalaženje curenja vode u vodoopskrbnom sustavu: pomoću uređaja za detekciju curenja vode, sustava za kontinuirano praćenje protoka te satelitskim načinom. Prikazana je IWA (International Water Association, Međunarodna udruga za vode) metodologija za izračun gubitaka vode te ILI pokazatelj (Infrastructure Leakage Index, Indeks curenja infrastrukture). Na primjeru Republike Hrvatske dani su osnovni podatci o vodoopskrbnom sustavu, i to: naselja obuhvaćena mrežom javne vodoopskrbe, ukupna duljina vodoopskrbne mreže, broj priključaka na vodoopskrbu, ukupna količina vode, ukupna količina isporučene vode i ukupni gubitci vode. Svi prethodno navedeni podatci dani su za razdoblje od 21 godinu, odnosno od 2001. do 2021. godine. Prikazani su koeficijenti korelacije za sve navedene varijable. Istražena je mogućnost modeliranja gubitaka vode s obzirom na određene varijable. Analizirani su podatci o gubitcima voda sa stajališta izgubljene pitke količine vode te s ekonomskog stajališta. Na kraju rada je zaključak s obzirom na prikazane podatke i provedenu analizu te osvrt na problematiku gubitka vod
School Outdoor Spaces as Urban Public Space Activators. Three Case Studies in Croatia
No full textIn this paper, the authors provide an overview of schools’ outdoor spaces. A brief analysis of their historical development is followed by a study of contemporary multifunctional use of school grounds primarily based on an interaction between the community and public urban spaces. Schools’ outdoor spaces have lately been comprehensively researched in light of the effects of the Covid-19 pandemic on teaching as well as the long-standing awareness of the importance of eco-friendly living. Architectural elements of schoolyards of the early twentieth- century Open Air Schools, created to improve children’s health, and the ensuing process of evolving school outdoor spaces beyond education, are detailed with a vision of connecting schools with the surrounding built environment. Through a comparative analysis of selected case studies in Croatia, the paper presents three examples of interaction between primary school outdoor spaces and urban public spaces. This interaction is a viable future trend in school design and urban planning in view of the reduction of accessible community areas with the aim of bring education back to its origins in nature and urban public spaces
A Hybrid Artificial Neural Network—Particle Swarm Optimization Algorithm Model for the Determination of Target Displacements in Mid-Rise Regular Reinforced-Concrete Buildings
No full textThe realistic determination of damage estimation and building performance depends on target displacements in performance-based earthquake engineering. In this study, target displacements were obtained by performing pushover analysis for a sample reinforced-concrete building model, taking into account 60 different peak ground accelerations for each of the five different stories. Three different target displacements were obtained for damage estimation, such as damage limitation (DL), significant damage (SD), and near collapse (NC), obtained for each peak ground acceleration for five different numbers of stories, respectively. It aims to develop an artificial neural network (ANN)-based sustainable model to predict target displacements under different seismic risks for mid-rise regular reinforced-concrete buildings, which make up a large part of the existing building stock, using all the data obtained. For this purpose, a hybrid structure was established with the particle swarm optimization algorithm (PSO), and the network structure’s hyper parameters were optimized. Three different hybrid models were created in order to predict the target displacements most successfully. It was found that the ANN established with particles with the best position revealed by the hybrid models produced successful results in the calculation of the performance score. The created hybrid models produced 99% successful results in DL estimation, 99% in SD estimation, and 99% in NC estimation in determining target displacements in mid-rise regular reinforced-concrete buildings. The hybrid model also revealed which parameters should be used in ANN for estimating target displacements under different seismic risks
Improving the Methodology of Seismic Risk Assessment for Residental Buildings
No full textU radu se predlaže unaprjeđenje metodologije procjene potresnog rizika za zgrade. Istraživanje na kojem se temelji doktorski rad pokrenuto je zbog spoznaja da potresna opasnost u područjima s umjerenom i malom seizmičnošću nije u potpunosti prepoznata te da postojeće metode procjene oštetljivosti zgrada, generiraju rezultate upitne pouzdanosti jer upotrebljavaju globalne procjene potresne opasnosti, modele izloženosti i tipologije zgrada. Istražene su mogućnosti unaprjeđenja procjena svih triju komponenata potresnog rizika. Za potresnu opasnost istražene su i dokazane prednosti koje upotreba probabilisčkog pristupa, spektara jednolike opasnosti te mikrozoniranja promatranog područja, imaju na konačne rezultate procjene potresne opasnosti. Predložene su nove atenuacijske jednadžbe za područja s umjerenom i malom seizmičnošću, procijenjene vrijednosti horizontalnih i vertikalnih vršnih ubrzanja za područjačije je temeljno tlo sastavljeno od dubokih slojeva lokalnog tla i dubokih geoloških sedimenata. Izrađene su karte seizmičkog mikrozoniranja promatranog područja. Pouzdanije modeliranje izloženosti istražilo se u smislu prikupljanja podataka o zgradama (i drugim elementima rizika) na licu mjesta te uzimajući u obzir samo one karakteristike zgrada koje su bitne za procjene potresne oštetljivosti. Izrađen je model izloženosti reprezentativnog grada s promatranog područja na temelju kojeg su predložene predominantne tipologije zgrada za koje je utvrđeno da mogu biti dodijeljene zgradama na svim područjima sa sličnom građevinskom praksom i primijenjenim građevinskim propisima. Rezultati istraživanja i modeliranja potresne opasnosti i izloženosti integrirani su u istraživanju načina unaprjeđenja proračuna potresne oštetljivosti zgrada. U procjeni potresne oštetljivosti upotrijebljeni su modifikatori oštetljivosti zbog utjecaja karakteristika temeljnog tla za čiji su proračun uzeti u obzir spektri jednolike opasnosti i amplifikacija lokalnih i dubokih slojeva temeljnog tla. Za sve zgrade iz modela izloženosti i predominantne tipologije proračunate su vrijednosti ukupnog indeksa oštetljivosti te predloženi razredi oštetljivosti. Istražena je i razlika vrijednosti indeksa oštetljivosti te promjenjivost razreda oštetljivosti s obzirom na najvjerojatniji i manje vjerojatan tip temeljnog tla. Rezultati modeliranja potresne opasnosti, izloženosti i oštetljivosti promatranog područja implementirani su u GIS sustav.The dissertation proposes the improvement of earthquake risk assessment methodologies for buildings.The research on which this work is based was initiated due to the knowledge that the earthquake risk in areas with moderate and low seismicity is not fully recognized and that the existing assessments of building vulnerability generate results of questionable reliability because they use global assessments of earthquake risk, exposure models and building typologies. Possibilities of improving the assessments of all three components of earthquake risk were explored. For the earthquake hazard, the advantages that the use of the probabilistic approach, uniform hazard spectra and microzoning of the observed area have on the final results of the earthquake hazard assessment have been investigated and proven. New attenuation equations were proposed for areas with moderate and low seismicity and also estimated were the values of horizontal and vertical peak accelerations for areas whose underlying soil is composed of deep layers of local soil and deep geological sediments. Seismic microzonation maps of the observed area were created. More reliable exposure modeling has been explored in terms of collecting data on buildings (and other risk elements) in site and considering only those building characteristics which are relevant to seismic vulnerability assessments. An exposure model of a representative city from the observed area was created, on the basis of which predominant typologies of buildings were proposed, for which it was determined that they could be assigned to buildings in all areas with similar construction practices and applied construction regulations. The results of research and modeling of seismic hazard and exposure are integrated in research on how to improve the calculation of seismic vulnerability of buildings. In the assessment of seismic vulnerability, vulnerability modifiers were used due to the influence of the characteristics of the foundation, for the calculation of which the spectra of uniform danger and amplification of local and deep layers of the foundation soil were taken into account. For all buildings from the exposure model and predominant typology, the values of the total vulnerability index and the proposed vulnerability classes were calculated. The difference in vulnerability index values and the variability of the vulnerability class were also investigated with respect to the most probable and less probable type of foundation soil. The results of modeling the earthquake hazard, exposure and vulnerability of the observed area we implemented in the GIS system
Design of the roof structure of a football stadium
No full textCilj diplomskog rada bio je istražiti krovne sustave nogometnih stadiona te na temelju toga proračunati jednu od odgovarajućih čeličnih krovnih konstrukcija. U prvom dijelu radu prikazani su osnovni nosivi sustavi krovnih konstrukcija te su prikazane prednosti i nedostaci čelika kao gradivnog materijala. Dani su osnovni koncepti projektiranja jednog takvog krovnog sustava. Prikazano je 10 krovnih konstrukcija na nogometnim stadionima kapaciteta za 20ak tisuća ljudi. Na kraju je dana usporedba tih stadiona. Nadalje, u drugom dijelu proračunata je sjeverna odnosno južna krovna konstrukcija nogometnog stadiona prema geometriji Opus arene u Osijeku. Programski paket koji je korišten za izradu prostornog modela krovne konstrukcije je SCIA Engineer 19.1. Analiza opterećenja i dimenzioniranje provedeno je prema HRN EN normama. Djelovanja koja su obuhvaćena tijekom analize opterećenja su vlastita težina, dodatno stalno, snijeg, vjetar, trenje o krovnu plohu i temperatura. Za dimenzioniranje elemenata korištene su najveće rezne sile iz mjerodavne kombinacije. Profili koji su usvojeni prema dimenzioniranju su HEA profili i kvadratni šuplji profili različitih izmjera. Iskazom materijala ukupna količina elemenata je 1426, što u konačnici daje masu od 178136 kg. Nacrti su izrađeni u programskom paketu Autodesk AutoCAD.The thesis aimed to investigate roof systems of football stadiums and, based on that, calculate one of the appropriate steel roof structures. The first part of the paper presents the basic load-bearing systems of roof structures and the advantages and disadvantages of steel as a building material. The basic concepts of designing such a roof system are given. Ten roof structures on football stadiums with a capacity for about 20,000 people are shown. At the end, a comparison of those stadiums is given. Furthermore, in the second part, the football stadium's north and south roof construction was calculated according to the geometry of the Opus Arena in Osijek. The software package used to create the 3D model of the roof structure is SCIA Engineer 19.1. Load analysis and dimensioning were done according to HRN EN standards. Actions that are included during the load analysis are self-weight, additional permanent load, snow, wind, friction on the roof surface and temperature. The largest internal forces from the relevant combination are used for dimensioning the elements. The profiles used according to the dimensioning are HEA profiles and square hollow profiles of different dimensions. According to the list of materials, the total amount of elements is 1426, which in sum gives a mass of 178136 kg. Drawings were made in the Autodesk AutoCAD software package
Influence of soft storey on rc multi story building response under earthquake loads
No full textGrađevine s mekim katom podložne su urušavanju i predstavljaju jedan od najopasnijih tipova visinski nepravilnih konstrukcija. U teorijskom dijelu rada prvo je kratko objašnjen fenomen mekog kata i dani su neki razlozi zbog kojih ova pojava nosi značajan rizik. Građevine s mekim katom zatim su objašnjene s arhitektonske i inženjerske točke gledišta, dan je kratak povijesni pregled značajnih istraživanja vezanih uz meke katove, podjela ovih građevina, kao i mjere ublažavanja. U praktičnom dijelu rada provedena je nelinearna dinamička analiza na ravninskim okvirima s mekim katom. Prvo je definiran osnovni numerički model konstrukcije – šesterokatni armirano-betonski okvir bez zidane ispune. Na temelju osnovnog modela izvedeno je sedam varijanti sa ispunom - šest sa diskontinuitetom zidane ispune koji se razlikuju po etaži i jedan sa zidanom ispunom na svim katovima, tako da je za potrebe seizmičke analize izrađeno ukupno osam različitih modela. Na modelima je provedena nelinearna dinamička analiza pomoću vremenskih zapisa sedam zabilježenih potresa. Uspoređeni su dobiveni uprosječeni rezultati i dan je grafički prikaz međukatnih pomaka za svaki pojedini model. Utvrđeni su optimalni i kritični model, kao i odnos između visinskog položaja mekog kata u građevini i veličine maksimalnog međukatnog pomaka. Na kraju su isprobane mjere koje bi ublažile utjecaj mekog kata na kritičnom modelu.Soft storey buildings are susceptible to collapse and represent one of the most dangerous types of vertically irregular buildings. In the theoretical part of the thesis, the soft storey phenomenon was first briefly explained and reasons why this occurrence carries a significant risk were given. Soft storey buildings were then presented from an architectural and engineering standpoint, and a brief historical overview of significant research related to soft storeys, classification of these buildings, as well as mitigation measures were given. For the practical part of the thesis, nonlinear dynamic analysis was carried out on plane frames with soft storeys. First, the main numerical model of the structure was defined - a six-storey reinforced concrete frame without infill walls. Based on the main model, seven variants with masonry infill were derived – six with infill discontinuity that differs by level and one with infill on all levels, so a total of eight different models were made for the purpose of seismic analysis. Nonlinear dynamic analysis was carried out on the models via the time-history method, using accelerograms of seven recorded earthquakes. The obtained averaged results were compared and a graphic representation of inter-storey drift ratio for each individual model was given. Optimal and critical model were determined, as well as the relation between the elevation of the soft storey in the building and the maximum inter-storey drift ratio. In the end, an attempt was made at mitigating the soft storey effect for the critical model