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V diplomski nalogi je predstavljena problematika masivnih betonov, tj. betonov, pri katerih je potrebna kontrola zaradi povišanja temperature v betonskem prerezu, ki je posledica sproščanja hidratacijske toplote ob vezanju cementa, in s tem povezanim nastankom razpok. Opisana je sestava cementa in vpliv sestave cementa na sproščanje hidratacijske toplote. Hidratacija je opisana po fazah, ki si sledijo med vezanjem cementa. Natančneje sta predstavljeni dve vrsti cementa, in sicer CEM I 42,5 R ter CEM III/B 32,5 N SR-LH, ki se med seboj bistveno razlikujeta glede na količino sproščene hidratacijske toplote. Podan je tudi izraz za opisovanje hitrosti sproščanja toplote med procesom hidratacije. V nadaljevanju naloge je prikazana diskretizacija problema in izpeljava enačb končnega elementa za povezan problem temperature in vlage. Izpeljane enačbe so nato uporabljene za sestavo sistema linearnih algebrajskih enačb, s pomočjo katerega izračunamo vrednosti temperature in koncentracije vlage v izbranih točkah. S pomočjo izpeljanih enačb je bil izdelan računalniški program v programskem okolju MATLAB, ki nam v nadaljevanju služi za numerično temperaturno vlažnostno analizo masivnega betona. V zadnjem delu diplomske naloge so predstavljeni rezultati treh analiz. Najprej analiziramo stopnjo povezanosti problema, pri čemer dobimo pri nepovezanem in delno povezanem problemu pričakovane rezultate. Nasprotno so pri povezanem problemu rezultati nezanesljivi, zato v nadaljevanju slednjega ne obravnavamo.. Z drugo analizo pokažemo, da za oceno temperature in koncentracije vlage v betonu upoštevanje delne povezanosti problema med fazo hidratacije ni potrebno, saj je razlika med povezanim in delno povezanim problemom zanemarljiva. S tretjo analizo pa pokažemo nujnost uporabe cementov z nizko stopnjo hidratacijske toplote pri izdelavi masivnih betonov. The present thesis deals with problems regarding mass concrete, in which the temperature rises due to the heat of cement hydration during the curing phase. A rise of temperature in concrete may result in cracking of young concrete. In the first part of the thesis cement composition and its influence on the released hydration heat is described. The hydration process is explained by its individual phases which occur during hardening of concrete. Two types of cement are presented, the CEM I 42,5 R and CEM III/B 32,5 N SR-LH. The hydration heat released by those two types of cement differs significantly. Also an analytical expression is given for evaluation of heat release of cement. Next, the discretization of the problem and the derivation of the coupled equations is made for a single finite element. The derived equations are used to form a system of linear algebraic equations, which is needed for calculation of the temperature and moisture distribution. Also the derived equations are used to write a computer program in MATLAB environment. The program is used as a tool for numerical hygrothermal analysis of mass concrete. The last part of the thesis presents the results of three different. The purpose of the first analysis is to investigate the influence of the coupling degree between heat and moisture transfer. While the results of non-coupled and semi-coupled models seem reliable, the results of a fully-coupled model are not realistic and therefore are not used in further analyses. The second analysis confirmed there is not much influence of semi-coupling on temperature fields, so the equations can be solved separately and still give useful results. The third analysis shows the necessity of low heat cement use in mass concrete structures.

V diplomski nalogi je bila izdelana ocena potresne odpornosti institutskega trakta stavbe UL FGG na Hajdrihovi ulici v Ljubljani s programoma 3Muri in SAP2000. V začetnem poglavju obravnavamo obnašanje zidanih konstrukcij med potresom in možne porušne mehanizme. Sledita opis določil Evrokoda 8-3, ki obravnava področje ocenjevanja obnašanja obstoječih stavb med potresi, ter opis postopka preverjanja potresne odpornosti zidov. V nadaljevanju je opisana poenostavljena nelinearna N2 metoda. V praktičnem delu naloge je predstavljen obravnavan objekt. Za dosego čim bolj primerljivih rezultatov modelov v obeh programih smo se z modeliranjem v SAP-u želeli čim bolj približati modelu v 3Muriju. Analiza lastnega nihanja je bila preverjena na treh modelih – modelu v 3Muriju, linijskem modelu v SAP-u ter ploskovnem modelu v SAP-u. Pri primerjavi nihajnih časov se je izkazalo, da modela v SAP-u dosežeta zgolj 67–96 % nihajnih časov modela v 3Muriju. Razlike smo pripisali različnemu podajanju masnih vztrajnostnih momentov, da bi njihov vpliv preverili, pa smo izvedli parametrično analizo. Izkaže se, da bi primerljive rezultate obeh programov dosegli s povečanjem masnih momentov v SAP-u na 220 % njihove začetne vrednosti, česar pa s fizikalno utemeljenim argumentom ne moremo upravičiti. Rezultati obenem kažejo, da sta modela v SAP-u med seboj bolj primerljiva, kot sta primerljiva posamezen model v SAP-u in model v 3Muriju. To smo pripisali uporabi različnih metod izračuna – SAP uporablja metodo FEM, 3Muri pa metodo FME. Da bi v čim večji meri eliminirali razlike med modeloma v različnih programih, smo kontrolo enakosti delovanja programov izvedli še na primeru enostavne konstrukcije brez odprtin. Izkaže se, da odstopanja res niso posledica različno definiranih elementov konstrukcije v obeh programih, zato se zdi pripis razlik različnim metodam izračuna smiseln. V nadaljevanju smo z obema programoma izvedli še nelinearno statično »pushover« analizo, pri čemer smo v SAP-u materialno nelinearnost zajeli z uvedbo plastičnih členkov. Ponovno se izkaže, da modela v različnih programih ne izkazujeta primerljivih rezultatov. In this thesis, the seismic performance assessment of the UL FGG building on Hajdrihova st. was investigated by 3Muri and SAP2000 software. In the first chapter the behaviour of masonry buildings under seismic actions are presented with an emphasis on failure mechanisms of structural components. Then follow the provisions of the Eurocode 8-3 standard, which deals with seismic assessment of existing buildings. Further on, the simplified N2 method based on non-linear static (pushover) analysis is introduced. In the practical part of the thesis the UL FGG building is presented. To achieve similar results in both programs we tried to make the model in SAP similar to 3Muri model as much as possible. Eigenvalue analysis was performed on three models – the 3Muri model, the SAP frame model and the SAP shell model. A comparison of natural periods has shown 4 % to 33 % smaller values for SAP models. The reason for differences could be in different mass moments of inertia. To check the influence of MMI, parametric analysis was performed. Results of the analysis have shown the need for enhancement of the SAP model MMI to 220 % of its original value, but this kind of adjustment cannot be physically explained. Analysis also shows that the results for two SAP models are much closer in comparison to each other than the results of any SAP model in comparison to the 3Muri model. This could be the result of different analysis methods – 3Muri using FME and SAP using FEM. In an attempt to eliminate the differences between models in both programs, a simpler model was analyzed. It turns out, the differences between models are not a consequence of the definition of structural components. More likely the difference is caused by not considering the same analysis method. Further on, the non-linear static analysis in both programs was investigated. Non-linear behaviour of the material in SAP model was modeled by defining the plastic hinges into elements of the/an equivalent frame. Again it turned out, the results of SAP and 3Muri models were far from similar.

Tako eksperimentalne raziskave, kot analize stavb in mostov po potresih kažejo, da pri armiranobetonskih stebrih obremenjenih s seizmično obtežbo pogosto pride do uklona vzdolžne armature. Na pojav uklona vzdolžne armature, njegovo numerično modeliranje, ter njegov vpliv na duktilnost armiranobetonskih stebrov smo se osredotočili v tem delu. Povzeli smo del dosedanjih raziskovalnih naporov na področju. Nato smo opisali numerične modele za nelinearno analizo armiranobetonskih stebrov in materialne modele s katerim modeliramo uklon vzdolžne armature. Iz baze eksperimentalnih rezultatov armiranobetonskih elementov smo izbrali skupino preizkušancev pri katerih je med eksperimentom prišlo do uklona vzdolžne armature. Iz histereznih odzivov, ki so bili podani v bazi, smo določili dosežene mejne pomike preizkušancev. Z nelinearno analizo smo izračunali mejne pomike preizkušancev z - in brez modeliranja uklona. Izračunane mejne pomike smo primerjali z mejnimi pomiki, ki smo jih določili iz eksperimentalno izmerjenih histerez. Za izbrani preizkušanec smo izračunali tudi histerezni odziv z uporabo različnih končnih elementov, ki so na voljo v programu OpenSees. Ugotovljeno je bilo da ima uklon majhen vpliv pri armiranobetonskih elementih, ki imajo razmerje med vzdolžnim razmikom stremen in premerom vzdolžne armature manjše od 6 in imajo zadosten premer stremenske armature. Trenutni računski modeli uklona vzdolžne armature, sicer dobro zajamejo padanje tlačne odpornosti armature, vendar pa imajo kljub temu probleme pri napovedi mejnih pomikov celotnega elementa. Za boljše modeliranje odziva armiranobetonskih stebrov bi bilo potrebno razviti materialne modele, ki bi upoštevali interakcijo med objetim betonskim jedrom in vzdolžno armaturo. Experimental research, as well as analysis of buildings and bridges damaged in earthquakes shows that in reinforced concrete columns longitudinal reinforcement often buckles under seismic loads. The onset of phenomena, the numerical modelling and effect of phenomena on the ductility of reinforced concrete columns are the focus of this thesis. We have summarized a portion of the current research efforts in the field. Then we have described numerical models for nonlinear analysis of reinforced concrete columns and material models which are used to describe buckling of longitudinal reinforcement. From a wider database of experimental data we have selected a group of specimens that shows signs of buckling. Experimentally observed ultimate displacements of selected specimens were determined from hysteretic responses that were included in the database. We have conducted nonlinear analysis to predict ultimate displacements of specimens, with or without buckling. Calculated ultimate displacements were compared with experimentally observed. For one specimen we have calculated hysteretic response using different finite elements available in OpenSees. We have gathered that the buckling of longitudinal reinforcement has little influence on columns that have unsupported length to bar diameter ratio smaller than 6 and have adequate diameter of transverse reinforcement. Although existing numerical models can describe lower resistance of the reinforcing bar in compression, they still have problems predicting displacements of the whole column. For better modelling of reinforced concrete columns models that take into account the interaction between confined concrete core and longitudinal reinforcement should be developed.

V diplomski nalogi predstavimo avtorski računalniški program za določanje požarne odpornosti enostavnih lesenih in armiranobetonskih konstrukcijskih elementov skladno s standardi Evrokod. Program je izdelan v programskem okolju Matlab® R2013a z uporabo orodja za razvoj grafičnih uporabniških vmesnikov GUIDE. Kot možnosti požarnih obremenitev uporabimo več nominalnih in eno modelirano (parametrično) požarno krivuljo. V primeru armiranobetonskih elementov uporabimo za določitev upogibne odpornosti metodo izoterme 500°C. Razpored temperatur po prečnem prerezu med požarom določimo s temperaturno analizo, ki jo izvedemo v povezavi z vključenim programom Heatko (Hozjan, 2009). V primeru lesenih elementov odpornost določimo z metodo zmanjšanega prečnega prereza in z metodo zmanjšanih materialnih karakteristik. Pri vsakem izračunu določimo začetno nosilnost in čas porušitve elementa pri kombinaciji vplivov za nezgodna projektna stanja. Nosilnost v odvisnosti od časa prikažemo na grafu. Program predstavimo z njegovo teoretično osnovo, navodili za uporabo in petimi različnimi primeri. The thesis introduces a computer program for determining fire resistance of simple timber and reinforced concrete structural elements in accordance with Eurocode standards. The program is developed in the programming environment Matlab® R2013a, using graphical user interface development tool named GUIDE. Thermal actions used in the program include a selection of nominal fire curves as well as one of the natural fire models – the parametric curve. The method used to determine fire resistance of reinforced concrete elements is the 500°C isotherm method. The temperature layout across the crosssection is determined by temperature analysis, which is done in conjunction with the implemented program Heatko (Hozjan, 2009). For timber elements are used the fire resistance is calculated by the reduced cross-section method and by the reduced properties method (simultaneously). The results for each calculation consist of initial capacity, time of failure and a graph displaying bearing capacity loss over time. The program is presented by its theoretical background, instructions for use and five different practical examples.

V diplomski nalogi projektiramo nadomestno jekleno strešno konstrukcijo in novo zunanje požarno stopnišče z dvigalom, za stavbo UL FGG na Hajdrihovi ulici. Najprej določimo zunanje obtežbe, ki vplivajo na streho in požarno stopnišče. Nato naredimo računski 3D model strešne konstrukcije in požarnega stopnišča v programu Scia Engineer. Nosilni sistem strehe je sestavljen iz pomičnih okvirov v prečni smeri in okvirov s centričnimi povezji v vzdolžni smeri. Pri požarnem stopnišču so nosilni štiri notranji in štiri zunanji stebri okoli katerih so nameščena vertikalna povezja. Med notranjimi in zunanjimi stebri je speljano stopnišče s podesti. V projektu naredimo za oba primera analizo mejnega stanja nosilnosti in potresno analizo, pri kateri uporabimo metodo vodoravnih sil. Pri strehi je potres merodajen pri dimenzioniranju vertikalnih povezij, za ostale elemente pa je merodajna analiza MSN. Pri požarnem stopnišču je za stebre in vertikalna povezja merodajen potres, ostale elemente pa dimenzioniramo na analizo za MSN. Pri obeh primerih projektiramo še spoje in narišemo pozicijske in detajlne načrte. This thesis is the project of replacing the steel roof construction and the outside fire staircase with elevator of the UL FGG building on Hajdrihova street. First we determine the loads for the roof and the fire staircase. Then we make a 3D model in the program Steel Engineer in order to calculate the internal forces. For the main structure of the roof we select the frame in one direction and frame with centric bracing in other direction. The fire staircase has four internal columns and four external columns around which vertical bracing is placed. Between internal and external columns there are stairs with intermediate platforms. In this project we make the ultimate limit state analysis and seismic analysis for both designs. The seismic analysis is performed using a simplified method of horizontal forces. At roof seismic analysis is used to design vertical bracings and to design the rest of the elements we use the ultimate limit state analysis. At fire staircase seismic analysis is used to design columns, beam and vertical bracings and the ultimate limit state analysis is used for the rest of the elements. In both cases we also design joints and draw the position and detail plans.

Cilj diplomske naloge je predstaviti uporabo stekla v gradbeništvu, ne samo kot glavnega elementa zasteklitve, ampak tudi kot konstrukcijskega materiala, ki je sposoben prenašati različne (nezanemarljive) obtežbe. Trenutni arhitektski trendi in tehnološki razvoj nakazujejo do sedaj nepredstavljivo uporabo stekla v arhitekturi in gradbeništvu - predvsem ko gre za velike steklene površine - ter na novo definirajo vlogo stekla v gradbeništvu – tudi kot konstrukcijskega materiala. V uvodnem delu diplomske naloge je predstavljena zgodovina stekla. Sledi pregled kemijskih in fizikalnih lastnosti stekla ter opis vrst stekla in njihove izdelave, kjer sem se osredotočil na stekla, ki se uporabljajo kot konstrukcijska, to so lamelirana in toplotno obdelana stekla. Prikazani so tipični spoji pri steklenih konstrukcijah. V osrednjem delu naloge so predstavljeni trenutni postopki načrtovanja nosilnih steklenih konstrukcijskih elementov, v zadnjem delu naloge pa so podani računske primeri, ki se nanašajo na tipične steklene panele. The goal of this thesis is to analyse tehnical characteristics and usability of glass, used in construction not just as main element of glazing, but also as construction material, which has ability to carry the loads. I will represent recent procedures of planing with carry – load glass construction element. Presented are the current procedures in the design of load-bearing glass construction elements. In the introductory part of the thesis is presented the history of glass and glass features. Followed by an overview of the chemical and physical properties of glass, and the production of glass. Later, I focused on the current standards, and calculations in the use of glass as a carrier material.

Diplomska naloga obravnava uporabo sodobnih računalniških orodij za geometrijsko modeliranje v procesu projektiranja objektov. Z vpeljavo parametričnega opisa geometrije v modelirniku 3D ter s povezavo modelirnika s programom za računanje konstrukcij, se odpirajo možnosti za avtomatično izmenjavo podatkov med programi za design in analizo konstrukcij. To lahko vodi k izboljšavi procesa projektiranja objektov. V prvem delu naloge sem predstavil osnove matematičnega zapisa geometrijskih elementov NURBS (angl. Non-Uniform Rational Basis Spline), ki jih uporabljata računalniški program za geometrijsko oblikovanje Rhinoceros in njegov dodatek Grasshopper. V drugem delu naloge sem predstavil parametrizacijo geometrije enostavnih ploskovnih in prostorskih paličnih konstrukcij v programu Rhinoceros (Grasshopper) ter njegovo povezavo s programom za analizo konstrukcij SAP2000. Znotraj okolja Grasshopper sem uporabil različne dodatke za ovrednotenje geometrije, vključno z genetskim optimizacijskim algoritmom, ki sem ga uporabil za interaktivno iskanje primerne oblike konstrukcije pri predpisanih pogojih. V zadnjem delu naloge je prikazana specifična nadgradnja omenjene povezave z vpeljavo novega vmesnika, ki sem ga izdelal v programskem jeziku Visual Basic.NET za uporabo v okolju Grasshopper. This graduation thesis comprises the use of modern geometry design software in the process of structural design. By implementing parametrically designed geometry and interactively linking 3D computer graphics application software with structural analysis software, tasks involved in structural design (e.g. automatic design data transfer) can be significantly improved. In the first part of the thesis, the basics of NURBS (Non-uniform Rational Basis Spline) mathematical elements are briefly presented, since the here used geometry design software Rhinoceros, and its add-on Grasshopper, are based on the NURBS. In the second part of the thesis examples of parametric geometrical design of simple space frame and shell structures are presented, along with a linking procedure beetwen Rhinoceros and structural analysis software SAP2000. In order to evaluate suitability of structural geometry, several Grasshopper based add-ons were tested out including specific genetic optimization algorithms. The genetic algorithms allow us to find optimal structural geometry due to predefined objective function and constraints. In the final part of the thesis, a new Grasshopper based Rhinoceros-SAP2000 interface/component is introduced which was programmed by using Visual Basic.NET scripting language.

V diplomski nalogi je izdelana ocena potresne odpornosti stare upravne stavbe Rudnika živega srebra Idrija. V prvem delu naloge je predstavljeno obnašanje zidanih stavb med delovanjem potresa in opis tipičnih porušnih mehanizmov zidov. Sledi kratek opis določil standarda Evrokod 8-3, ki obravnava področje ocenjevanja obnašanja obstoječih stavb med potresi. Po korakih je opisana poenostavljena metoda N2, ki temelji na nelinearni statični analizi. Na koncu sledi še predstavitev programa 3Muri, ki smo ga uporabili za račun potisnih krivulj. V drugem delu naloge je sprva opisana upravna stavba, ki je zgrajena iz nepovezanih kamnitih in opečnih zidov. Zaradi nepoznavanja dejanske kvalitete obstoječih materialov smo za obe vrsti zidovja iz literature privzeli po tri nabore mehanskih lastnosti. Pripravili smo pet modelov z različnimi kombinacijami vrednosti mehanskih lastnosti opečnega in kamnitega zidovja, na podlagi katerih smo ocenili potresno odpornost konstrukcije. Na osnovi deterministične analize smo ugotovili, da stavba ni sposobna prenesti pričakovanega projektnega pospeška temeljnih tal ag = 0,23 g in tako ne izpolnjuje zahtev standarda Evrokod 8. Velika ranljivost konstrukcije je bila posledica zelo nizkih vrednosti strižnih trdnosti privzetih materialov, ki smo jih skladno s standardom Evrokodom 8-3 delili še s faktorjem zaupanja CF = 1,35. Različne kombinacije mehanskih lastnosti zidovja so povzročale različne oblike porušnih mehanizmov konstrukcije. Zaradi majhnih razlik med strižnimi trdnostmi privzetih materialov se potresne odpornosti posameznih modelov niso bistveno razlikovale. Vrednosti koeficientov potresne odpornosti SRCu so variirali med 0,09 in 0,12, kar se je dobro ujemalo z vrednostjo, ki je bila ocenjena v projektu POTROG (2013). Ocenjujemo, da so mejni pospeški tal za obravnavan objekt verjetno podcenjeni, kar je posledica varnostnih faktorjev, ki jih je potrebno upoštevati v primeru nepopolnega poznavanja konstrukcije. In this thesis, the seismic performance assessment of the former administration building of RŽS Idrija is investigated. The first part of the thesis presents the behaviour of masonry buildings under seismic actions, and typical failure mechanisms of masonry walls, followed by the provisions of the Eurocode 8-3 standard, which deal with seismic assessment of existing buildings. Further on, the simplified N2 method based on non-linear static (pushover) analysis is introduced, followed by the presentation of 3Muri software. The second part of the thesis begins with a description of the administration building, which was build out of stone and brick masonry walls without adequate floor-to-wall connections. Not knowing the exact quality of the existing materials, three sets of mechanical properties for both types of masonry were obtained from the literature. The seismic performance assessment was based on five models of the structure each with different combination of mechanical properties of stone and brick masonry. The results of the deterministic analysis have shown that the building is incapable of withstanding the expected design ground acceleration ag = 0,23 g and does not meet the requirements of the Eurocode 8 standard. The great vulnerability of the structure is a consequence of very low shear strength values of the masonry, which were assessed from previous studies and, in accordance with Eurocode 8-3, divided by the confidence factor CF = 1,35. Different combinations of mechanical properties of masonry have lead to different types of failure mechanisms of the structure. Due to small differences between shear strength values of the materials the seismic resistance of our models did not differ significantly. The seismic shear coefficient SRCu was between 0,09 and 0,12 which complied with the coefficient estimated in the POTROG (2013) project. It is estimated that the limit-state peak ground acceleration is most likely underestimated, which is the consequence of safety factors that need to be considered in the case of incomplete knowledge of the structure.