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Promjenjivost stanja slanosti voda obalnog vodonosnika pod utjecajem operativnih režima melioracijskog sustava, plimotvornih oscilacija i hidroloških uvjeta rijeke Neretve : disertacija
No full textOne of the areas of prior interest for the Republic of Croatia in terms of water conservation and water needs, especially for irrigation of agricultural crops, is the river Neretva delta. This area represents the largest agricultural area on the Croatian coast and is the source of existence for the local population. Managing the area has become a complex task given the intensive agricultural activities, the large number of people living near the area of interest, significant seawater intrusion (SWI) and ongoing climate changes manifested by indicators such as sea level rise and increasingly unpredictable precipitation. Therefore, the need to understand the processes responsible for creating favorable/unfavorable conditions in both, surface and groundwater, is self-evident. A review of the available literature reveals that SWI in the coastal aquifer system of the Neretva Valley, with a focus on external loadings and their effect on ground and surface water has not been sufficiently investigated. The influence of the operative regime of the melioration system, the hydrological regime of the river Neretva and the tidal characteristics of the Adriatic Sea to ground and surface water fluctuations along the study area was established as the primary scope of this thesis. A variety of methodological approaches was used throughout the thesis to analyze and investigate the impact of SWI on the Neretva coastal aquifer system. Despite the strong effect of the SWI, the area of interest is defined as a complex system that can be controlled naturally or by management. In order to investigate the interaction between factors controlling the surface and ground water along the Neretva Valley in conjunction with SWI, a monitoring system was designed and implemented to collect pertinent data sets and time series. An investigation was conducted utilizing time series in the temporal and frequency domains. The application of cross correlation methods, the Discrete Fourier Transform and the Continuous Wavelet Transform provided insights into the interdependence of analyzed ground and surface water parameters. Based on past in-situ work and time series of sea water elevation and piezometric head, the study area was hydrogeologically characterized. Previously collected in-situ data were used for the conceptualization of the coastal aquifer system. Tidal methods were upgraded to incorporate tidal signals with more than one harmonic constituent to improve the method’s capacity. Findings are focused on determining specific storage, hydraulic conductivity and leakance between shallow unconfined and deeper confined aquifer units. Novel in-situ and laboratory results were utilized to bolster these findings. The confinement of the deeper aquifer was confirmed in two ways: i) by using frequency analysis of constituents typical for confined conditions which confirm confinement of deeper aquifer and ii) by using ERT results which do not evidence the absence of confining clay layer along the study area. The determined values of hydraulic conductivity were consistent with the gravely material, which was confirmed by interpreting the characteristic grain values determined in the laboratory from borehole cores taken from the study area. Based on the hydrogeological characterization and determination of the connectivity between the geological units of the aquifer, the predominant SWI corridors characterizing rain and dry seasons were identified. To comprehend the transient nature of surface and groundwater parameters such as temperature, piezometric head, and electrical conductivity, a number of external loadings were considered. The confined aquifer appears to maintain its electrical conductivity regime independently from the unconfined aquifer above and vice versa. The electrical conductivity in the confined aquifer shows no significant correlation with tidally-induced oscillations, while piezometric head as observed within the confined aquifer is shown to be driven by tidal oscillations. In addition to the confined aquifer, it was demonstrated that the Adriatic Sea is the dominant factor controlling the groundwater regime in the Diga area, as found in the unconfined aquifer. The melioration system’s operative regime creates favorable agricultural conditions in the study area. As a result, groundwater has been delineated below sea levels, thereby creating active SWI conditions that increase the inflow of seawater from the Adriatic Sea. The majority of precipitation occurs during the rain season, which creates an imbalance in the natural aquifer recharge. In both rain and dry seasons, the river Neretva's hydrological regime plays a dominant role but with opposite effects. During the dry season, seawater intrudes upstream along the Neretva riverbed, generating a source of seawater that impacts the Jasenska region. Specific attention has been given to the sub melioration systems of Vidrice and Opuzen ušće. The groundwater of the coastal area of Opuzen ušće, called Diga, was identified as dominantly tide controlled, while the Vidrice area is predominantly influenced by the presence of upstream springs of brackish water which enter the melioration system. It was discovered that only the Vidrice area has higher salinity during the rain season than during the dry season. The operative regime of the melioration system controls the dynamics of water quality as found along the Vidrice area, while the groundwater in the Jasenska area is salinized primarily by the Neretva River.Jedno od područja od primarnog interesa za Republiku Hrvatsku u smislu očuvanja stanja voda i potreba za vodom primarno za potrebe navodnjavanja poljoprivrednih kultura jest područje donje Neretve, točnije, područje delte rijeke Neretve od grada Opuzena do Jadranskog mora. Područje donje Neretve predstavlja najveće poljoprivredno područje na hrvatskoj obali, a za lokalno stanovništvo koje značajan postotak primarni izvor prihoda osigurava iz poljoprivrednih djelatnosti, predstavlja izvor egzistencije. Do sredine 20.tog stoljeća, u većoj mjeri močvarno područje, sa značajnim vodoprivrednim i infrastrukturnim zahvatima i objektima pretvoreno je u područje pogodno za poljoprivredne djelatnosti. S obzirom na intenzivnu poljoprivredu, značajnu koncentraciju ljudi koji žive u području koje gravitira području od interesa, utjecaja intruzije morske vode (IMV) uslijed blizine mora i klimatskim promjenama za očekivati je u bližoj budućnosti značajne poteškoće u pogledu dugoročnog održanja kvalitete vode prihvatljive za navodnjavanje poljoprivrednih kultura. Iz pregleda dostupne literature uočava se nedostatak cjelovitog istraživanja u segmentu IMV, nedostatak razumijevanja vanjskih utjecaja, operativnog režima sustava, sustava obrane od poplava i identifikacije glavnih koridora unosa morske vode u obuhvat. Kako bi se analizirao proces IMV-a i utjecaj IMV-a u dolini Neretve u radu su primijenjeni razni metodološki pristupi. Kako bi se istražio proces IMV-a, ali i procesi koji utječu na IMV u području interesa, osmišljen je i implementiran sustav monitoringa površinskih i podzemnih voda. Prikupljeni podaci su analizirani u vremenskoj i frekvencijskoj domeni primjenom crosskorelacijskih modela, diskretne Fourier-ove transformacije i kontinuirane Wavelet transformacije u svrhu analiziranja parametara podzemnih i površinskih voda, ali i njihove međusobne povezanosti. S obzirom na prethodne geofizičke i geomehaničke istražne radove definiran je konceptualni model vodonosnika doline Neretve. Vremenske serije razine mora i potencijala u vodonosniku korištene su u svrhu hidrogeološke karakterizacije vodonosnika pod tlakom. Metode iz domene Tidal Methods se unaprjeđuju s kapacitetom obrade realnih polikromatskih signala plime i oseke, a sve u svrhu pouzdanijeg određivanja hidrogeoloških parametara poput parametra zapremine, hidrauličke vodljivosti i procjeđivanja između dubokog vodonosnika pod tlakom i plitkom vodonosnog sloja sa slobodnim vodnim licem. Utvrđeni hidrogeološki parametri su verificirani s geofizičkim, geomehaničkim i laboratorijskim rezultatima. Karakterizacija dubokog vodonosnika pod tlakom potvrđena je analizom karakterističnih konstituenata u vodonosniku pod tlakom u frekvencijskoj domeni i ERT rezultatima koji ukazuju na neprekinutost glinenog sloja između plitkog i dubokog vodonosnog sloja. Verifikacija dobivenih vrijednosti hidrauličke vodljivosti vodonosnika pod tlakom je provedena usporedbom s rezultatima analiziranih uzoraka materijala iz istražne bušotine napravljene na području interesa. S obzirom na prethodno utvrđene hidrogeološke parametre i utvrđene ograničenosti vodonosnika pod tlakom, definirani su glavni koridori unosa morske, ali i svježe vode u područje interesa u kišnom i sušnom razdoblju. Kako bi se dodatno razumjele vremenski promjenjive karakteristike površinskih i podzemnih voda poput razine podzemne ili površinske vode, električne vodljivosti i temperature analizirani su razni vanjski utjecaji. Električna vodljivost u vodonosniku pod tlakom ima relativno konstantnu vrijednost tokom cijele godine, dok su promjene potencijala u vodonosniku uzrokovane plimotvornim oscilacijama mora. Osim utjecaja na duboki vodonosnik oscilacije razine mora imaju i dominantni utjecaj na režim podzemnih voda u vodonosniku sa slobodnim vodnim lice na području Dige. Rad infrastrukture navodnjavanja i odvodnje primarno definira režim podzemnih voda u smislu osiguranja zone pedološkog sloja. Ova činjenica, iako primarno zamišljena s idejom osiguranja povoljnih poljoprivrednih uvjeta, za posljedicu je imala i kreiranje uvjeta za ostvarenje aktivne intruzije morske vode, te povećan unos morske vode u obalni vodonosni sustav i intenziviranje IMV-a u ovom području. Tokom godine većina pale oborine se ostvari u kišnom razdoblju što za posljedicu ima disbalans u režimu površinskih i podzemnih voda. Hidrološki režim rijeke Neretve ima ključnu ulogu na stanje podzemnih voda u području Jasenska i u kišnom i sušnom razdoblju. U sušnom razdoblju prisutnost klina morske vode u rijeci Neretve je čini slanim rubnim uvjetom, dok je u kišnom s povećanjem protoka i potiskivanjem klina morske vode prema ušću zabilježen suprotan utjecaj rijeke Neretve na područje Jasenska. Za razliku od Jasenske, područje Dige je dominanto pod utjecajem mora, a područje Vidrica je pod utjecajem slanih izvora koji se nalaze uz rub ovog područja te zaslanjuju melioracijske kanale na ovom području. Područje Vidrice predstavlja jedino područje u obuhvatu koje ima veću slanost podzemnih i površinskih voda tokom kišnog razdoblja u odnosu na sušno razdoblje. Režim rada melioracijskog sustava kontrolira kvalitetu vode na području Vidrica, a rijeka Neretva ima glavni utjecaj na zaslanjivanje područja Jasenska
Discrete numerical modelling of reinforced concrete structures by embedded discontinuity approach : doctoral thessis
No full textU ovom radu predstavljen je novi diskretni numerički model s ugrađenim diskontinuitetom za analizu armirano betonskih konstrukcija izloženih statičkom i dinamičkom opterećenju. Unutar diskretnog modela koji se koristi za simulaciju ponašanja betonske konstrukcije zasnovanog na Voronoi poligonima, koji su povezani kohezivnim vezama modeliranima pomoću Timoshenkovih greda, implementirana je armatura koja se postavlja neovisno o postojećoj mreži diskretnih elemenata betona. Modeliranjem međudjelovanja između armature i betona omogućen je prijenos sila između betonskih i armaturnih elementa te simuliranje klizanja armature. Sve materijalne komponente armiranog betona (beton, armaturne šipke i međudjelovanje betona i armature) modelirane su s istim elementima, Timoshenkovim gredama s ugrađenim diskontinuitetom, koje omogućuju opis heterogenosti u materijalu, nelinearno deformiranje i pucanje betona i armature, kao i klizanje i izvlačenje armaturnih šipki. Kako bi se opisalo ponašanje pojedinih komponenti materijala implementirani su modeli ponašanja materijala i to model oštećenja za opisivanje ponašanja krtih i kvazi-krtih materijala poput betona, te model plastičnosti za opisivanje ponašanja čelika i međudjelovanja između armature i betona. Za modele oštećenja i plastičnosti detaljno je prikazan postupak dobivanja lokalnih/unutarnjih varijabli. Za analizu dinamičkog opterećenja razvijen je dinamički model dodavanjem utjecaja inercijalnih sila. Integracija u vremenu se provodi primjenom Newmarkove metode, koristeći sve prethodno razvijene formulacije za statički model. U sklopu dinamičkog modela prikazana je analiza energija u diskontinuitetu za model oštećenja te za model plastičnosti. Validacija novog modela oštećenja-omekšavanja izvršena je na testovima sa statičkim i dinamičkim opterećenjem. Verifikacija i validacija modela za analizu amirano betonske konstrukcije napravljena je za nekoliko statičkih i dinamičkih testova te su dobiveni rezultati uspoređeni s rezultatima dobivenim poznatim analitičkim i numeričkim metodama te dostupnim eksperimentalnim ispitivanjima.In this paper a novel discrete lattice numerical model with embedded discontinuity was presented for modelling of reinforced concrete structures exposed to static and dynamic load. Into discrete lattice model which is used for concrete behaviour and was represented here by Voronoi cells and Timoshenko beams as cohesive links between them, reinforcement bars were implemented and positioned in the concrete domain irrespective of the Voronoi cells. In order to provide force transfer between concrete and reinforcement and to represent bond-slip, the bond between concrete and reinforcement was modelled. All material components of reinforced concrete (concrete, steel bars and bond between concrete and reinforcement) were modelled with the same elements, Timoshenko's beams with embedded discontinuities which enable the representation of heterogeneity of material, nonlinear deformation, cracking of concrete, rupture of reinforcement, bond-slip and pulling out of the reinforcement. In order to describe each material component behaviour, a damage constitutive model was implemented for brittle and quasi-brittle materials like concrete, and a plasticity constitutive model was implemented for steel and bond between concrete and reinforcement. For the damage model and the plasticity model computation of internal variables was presented in detail. For dynamic analysis, dynamic model was developed by adding inertial contributions. Newmark algorithm is used for time integration, with existing formulation for static model. Also, energy analysis for discontinuity for the damage and the plasticity model was presented. Validation of novel softening-damage model was performed for static and dynamic tests. Verification and validation of model for the analysis of reinforced concrete structure was performed for several of static and dynamic tests and results of numerical simulations of this model were compared with results obtained by analytical and numerical methods and results obtained by experiments
Reinforcement of Cement Screed with Textile Waste : Undergraduate Thesis
No full textIscrpljivanje prirodnih resursa i odlaganje otpada danas su jedni od najvećih problema zaštite okoliša. U modernoj industriji sve se više teži korištenju recikliranog otpada, pa tako i u građevinarstvu. U ovom radu ispitani su uzorci cementnog estriha ojačanog tekstilnim otpadom, te uzorci ojačani polipropilenskim vlaknima. Izvršeno je ispitivanje sadržaja zraka i gustoće u mješavinama u svježem stanju te je nakon 28 dana starosti uzoraka provedeno ispitivanje na tlačnu i savojnu čvrstoću. Dobiveni rezultati pokazali su da dodatak od 5% tekstila povećava tlačnu, ali ujedno smanjuje vlačnu čvrstoću uzorka. Ostali uzorci nisu pokazali zadovoljavajuće rezultate.The exhaustion of natural resources and waste disposal are among today’s largest environmental issues. In modern industry, there is an increasing tendency to use recycled waste, including construction. In this paper, samples of cement screed reinforced with textile waste and samples reinforced with polypropylene fibers were examined. The air content and density of the mixtures were tested in the fresh state, and after 28 days of age, the samples were tested for compressive and flexural strength. The obtained results showed that the addition of 5% of textile increases the compressive strength, but at the same time decreases the tensile strength of the sample. Other samples did not show satisfactory results
Selection of Solutions for Reconstruction and Upgrade of Drainage System with Construction of Wastewater Treatment Plant with Discharge Pipeline : Master's Thesis
No full textU radu je obrađena višekriterijalna analiza metodom Promethee za izbor varijantnog rješenja rekonstrukcije sustava odvodnje grada Sinja. Dobiveni rezultati grafički su prikazani putem softvera Visual Promethee.This paper demonstrates a multi-criteria analysis using the Promethee method for the selection of a variant solution for the reconstruction of the drainage system of the city of Sinj. The obtained results are graphically displayed via Visual Promethee software
Analysis of the Existing and New Solution for Entering the Split Ferry Port : Master's Thesis
No full textZbog razvoja turizma i povećanog priljeva vozila prema trajektnoj luci Split, trenutni prilazi luci nisu u mogućnosti prihvatiti povećano prometno opterećenje. Zbog toga je kroz projekt Istočna obala planirana izgradnja novog ulaza u trajektnu luku. Ovim radom prikazana je analiza prometa postojećeg stanja i novog rješenja ulaza u trajektnu luku Split, izvršene su simulacije u programu TSIS-CORSIM te su prikazani dobiveni rezultati kao i analiza ključnih točaka.Due to the development of tourism and the increased inflow of vehicles to the Split ferry port, the current approaches to the port are not able to accommodate the increased traffic load. Therefore, the construction of a new entrance to the ferry port is planned through the project East Coast. This paper presents a traffic analysis of the existing situation and a new solution for the entrance to the Split ferry port, simulations were performed in the TSIS-CORSIM program and the results are presented, as well as an analysis of key points
Main Project of the Hotel Tar : Master's Thesis
No full textU ovom radu prikazan je glavni projekt konstrukcije objekta ugostiteljsko-turističke namjene – hotela smještenog u naselju Tar. Predmetna građevina je slobodnostojeća, s jednom podzemnom i tri nadzemne etaže. Konstrukcija građevine je izvedena u armiranom betonu, u potpunosti monolitne izvedbe, s armirano betonskim zidovima, stupovima te armirano betonskim pločama i gredama koje čine međukatnu konstrukciju. Projekt obuhvaća tehnički opis konstrukcije, opće i posebne tehničke uvjete, plan kontrole i osiguranja kvalitete, proračun nosivih konstrukcijskih elemenata i karakteristične građevinske nacrte i armaturne planove.This paper presents the main design of a hospitality and tourism facility – a hotel located in Tar. The building in question is a detached structure with one underground and three above-ground floors. The construction is made of reinforced concrete, entirely monolithic in execution, with reinforced concrete walls, columns, and reinforced concrete slabs and beams forming the floor structure. The project includes a technical description of the structure, general and specific technical requirements, a quality control and assurance plan, structural analysis of the load-bearing elements, and characteristic construction drawings and reinforcement plans