Eksperimentalne in numerične preiskave za določitev kontroliranega odziva večslojne kamnite zidovine

V sklopu naloge je bilo študirano obnašanje troslojnih kamnitih zidov, in sicer obnašanje pri tlačnih obremenitvah in pri strižnih obremenitvah v ravnini zidov. Izvedene so bile obsežne eksperimentalne preiskavetlačni in strižni testi skupaj 18 zidov ter spremljajoče preiskave konstituentov (malte in kamna). Preskušani kamniti zidovi so značilni predvsem za reprezentativne starejše objekte, ki pogosto predstavljajo pomemben del naše kulturne dediščine. Za testiran tip zidov je bil sistematično analiziran vpliv morfologije zidov (sestave po prerezu), različnih nivojev pred-obremenitev ter robnih pogojev vpetja na različne karakteristike obnašanja zidov. Poleg nosilnosti je bil poudarek na analizi pomikov ter poškodovanosti zidov v karakterističnih stanjih obnašanja. V odvisnosti od robnih pogojev je pri strižnih testih prišlo do različnih porušnih mehanizmov zidovupogibnega, mešanega in diagonalnega strižnega, pri čemer v nasprotju s pričakovanji izven-ravninski mehanizem ni bil merodajen. Do slednjega je prišlo bolj opazno pri višjih pred-obremenitvah zidov v fazi mehčanja zidov. Za testirani tip zidov povezovalni kamni preko prereza zidu niso prispevali ne k večji nosilnosti ne k večjim mejnim pomikom. Eksperimentalni rezultati nosilnosti in mejnih zasukov so bili primerjani z analitičnimi modeli. Strižno nosilnost se zadovoljivo oceni z obstoječimi modeli za porušitve, do katerih je pri testih dejansko prišlo. Doseženi mejni pomiki zidov so bili pri testih veliko večji, kot so dovoljeni mejni pomiki v standardih (EN 1998-3 in FEMA 306). Ker je pri objektih kulturne dediščine poleg same konstrukcije pogosto v interesu ščititi tudi različne poslikave, je bil na zidove nanesen apneni omet, ki je služil študiju obnašanja umetnostih elementov zidov. Določene so bile vrednosti mejnih zasukov zidov za 4 stanja poškodb ometov, ki so uporabne za oceno potresne odpornosti objektov s stališča poškodovanosti ometov. Drugi del naloge obravnava utrjevanje poškodovanih troslojnih kamnitih zidov. Ker je navadno pri utrjevanju historične zidove zahtevana uporaba kompatibilnih materialov, reverzibilnost ukrepov, itd., je bil v sklopu naloge razvit nov sistem utrjevanja. Poškodovani zidovi so bili injektirani s cementno-apneno injekcijsko mešanico in dodatno utrjeni s stekleno vrvico, s podaljšano apneno malto vgrajeno v horizontalne maltne spojnice, ter z vrvico tudi prečno povezani. Skupaj je bilo z različnimi kombinacijami ukrepov utrjenih in dodatno testiranih 10 zidov. Injektiranje se je izkazalo kot primeren sanacijski ukrep, vrvice v spojnicah pa so povečale duktilnost zidov ter v določenem primeru tudi nosilnost. Rezultati testov neutrjenih zidov so bili aplicirani na dejanski objekt. Na primeru Vile Vipolže je bil numerično analiziran vpliv predpostavke mejnih pomikov zidov na potresno obnašanje objekta, računano z nelinearno statično analizo konstrukcije na modelu z ekvivalentnimi okvirji. Glede na rezultate (nezanemarljivo povečanje odpornosti v primeru povečanja pomikov) bi bilo za bolj duktilno zidovino, kot je navadno zgodovinska, smiselno dodatno preučiti smotrnost povečanja mejnih vrednosti zasukov v predpisih.In the thesis, the behaviour of three-leaf stone masonry walls under compression loading and in-plane shear loading is studied. An extensive experimental campaign was conducted on 18 walls, accompanied by tests on masonry constituents (mortar and stone). The type of the tested masonry is typical for older representative buildings, which often present important cultural heritage assets. Influence of morphology, level of pre-compression and boundary conditions on various characteristics of the walls behaviour was systematically studied. Besides the strength, the greatest emphasis was on the analysis of the displacement capacity and damage of the walls at characteristic stages of their response. Due to various boundary conditions, different failure mechanisms developedrocking, mixed and diagonal shear. Leaf separation and the out-of-plane mechanism of the wall was not critical as expected. It developed more evidently in the post-peak phase of the tests for specimens with higher pre-compression. The presence of connecting stones had no influence neither on the obtained shear strength nor on the displacement capacity of the walls. The experimental results were compared to results of analytical models for prediction of shear resistance. For the tested type of masonry, shear strength can be adequately estimated with existing models for the failure mechanisms that developed in the tests. Drift capacity of the walls was however significantly higher than drift capacity allowed in the code provisions (EN 1998-3 in FEMA 306). In heritage buildings also various artistic assets in the form of painted walls are often present. Lime plaster was applied to the walls in order to study its performance during cyclic shear loading. Reference drift values for walls at 4 different characteristic plaster damage states were determined. They can be used for performance based seismic assessment of historic buildings. The second part of the thesis deals with strengthening of the damaged three-leaf stone masonry walls. For monumental buildings there are usually strict demands upon the use of materials compatible to existing materials, reversibility, etc., therefore a new strengthening system was developed. Walls were retrofitted along the cracks with lime-cement grout, additionally strengthened with near surface mounted (NSM) glass cords and transversally connected10 walls were strengthened with various combinations of measures and re-tested. Grouting successfully retrofitted the walls, while NSM glass cords increased the displacement capacity and, in one case, also shear resistance substantially. Finally, the results of tests of the un-strengthened walls (drifts) were adopted for the numerical analysis of the seismic performance of an actual building (mansion Vipolže). Nonlinear static analyses using equivalent frame model were conducted. The influence of the assumed drift limits on the seismic resistance was analysed. The increase of seismic performance with increasing drift limits of walls is evident and it would be reasonable to further study the prospect of increasing the drift limits in the code provisions for types of masonry, which are more ductile (historical masonry)

Carcinogenicity of Styrene Oxide: Calculation of Chemical Reactivity

In this article the calculations of the activation free energy for a chemical reaction between styrene-7,8-oxide and DNA, in particular guanine at position N7, are reported. Calculations were performed by Hartree-Fock and DFT methods in conjunction with flexible basis sets. Effects of solvation were considered using the Langevin dipoles method. The calculated activation free energies are in good agreement with the experimental value of 26.52 kcal mol−1

Vulnerability Study of Urban and Rural Heritage Masonry in Slovenia Through The Assessment of Local and Global Seismic Response of Buildings

Uncertainties regarding the influence of modelling strategies for the evaluation of seismic vulnerability of\ud masonry buildings in Slovenia were studied on two case studies– damaged buildings from the rural area of NW\ud Slovenia hit by earthquakes in ’98 and ’04 and the urban buildings from the old city centre of Ljubljana. Two\ud strategies were applied – failure mechanisms analysis by means of FaMIVE methodology and non-linear\ud response analysis by means of storey and global response (SREMB and 3Muri). The accuracy in predicting\ud failure modes by FaMIVE was 50% considering the stock of investigated building in rural area. The most critical\ud failure mechanisms were due to out-of-plane loading. For urban architecture, in-plane failure due to weak\ud spandrels was the predominant one. The mechanism assessment yields more conservative results in respect to\ud non-linear approach and thus may be an efficient tool for the design of strengthening measures for heritage\ud buildings to prevent damage in lower intensity events with higher probability of occurrence

Sensitivity comparison of non-destructive methods for quality control of steel surface

Diplomsko delo temelji na primerjavi občutljivosti neporušitvenih metod za ocenjevanje kakovosti površine različnih materialov – jekel. V njem so opisane tri neporušitvene metode za pregledovanje kakovosti materialov in izdelkov, kot so zvari, odkovki in ulitki. Prva in hkrati splošna metoda je vizualna kontrola. Pri njej se zanašamo le na »dober« človeški vid, ki mora biti preverjen s pomočjo Jaeger testa in Landoltove ter Ishihare karte. Pri drugi tehniki za odkrivanje indikacij uporabljamo penetrante. To so posebne snovi, ki zapolnijo nepravilnosti na površini materiala. S pomočjo razvijalca penetrantje pokažejo indikacije. Pri tretji tehniki se pri pregledovanju uporabljajo posebni magnetni delci, ki zaradi magnetnega polja na nepravilnosti ustvarjajo sipanje polja. Ta pojav nam omogoča, da se delci naberejo na indikaciji in nam s tem pokažejo njeno lokacijo in velikost. Tehniki pregledovanja pravimo »tehnika z magnetnimi delci«. Pri vseh naštetih tehnikah uporabljamo standarde, v katerih so zapisane zahteve o kakovostnih nivojih in mejne vrednosti, ki govorijo o kakovosti površine, in sicer ali je ta dovolj kakovostna in s tem sprejemljiva za nadaljnjo uporabo. Vse naštete metode sem v raziskavi uporabila na dveh različnih materialih. Prvi je posebno konstrukcijsko jeklo S355, drugi pa orodno jeklo 42CrMo. Oba materiala sta magnetna, zato sem lahko na njiju uporabila vse tri metode. Posebnost orodnega jekla je, da vsebuje zelo veliko martenzita, zato je zelo trdo, obenem pa tudi zelo krhko. S tem bi lahko imela nekaj težav pri magnetenju, vendar se je izkazalo, da je stroj, s katerim sem magnetizirala, zelo zmogljiv in ustvarja močno magnetno polje, ob tem pa ne povzroči novih razpok. Na vsakem materialu sem izvedla vse preskusne metode in pet tehnik pregledovanja. V prvi fazi sem oba vzorca pregledala z vizualno tehniko in izpisala velikosti vseh odkritih indikacij. Nadaljevala sem s penetrantsko metodo, pri kateri sem uporabila tako barvni kot tudi fluorescentni penetrant. Tudi tu so bile odkrite indikacije. Pri tretji metodi je prišlo do manjše težave, saj sem ugotovila, da se obeh vzorcev zaradi oblike ne bo dalo namagnetiti na enak način. Konstrukcijsko jeklo je namreč imelo obliko sočelnega zvara, odkovek, ki je bil iz orodnega jekla, pa je bil v obliki profila. Tako je bilo treba za zvar uporabiti tehniko elektromagnetnih jarmov, pri odkovku pa sem si pomagala s strojem za magnetenje s kontaktnimi čeljustmi ter tuljavo. Ko je bila težava odpravljena, je bila na obeh vzorcih v nadaljevanju izvedena tehnika s črnimi in fluorescentnimi delci. Rezultat opravljenih preizkusov je bilo deset izpolnjenih tabel (z upoštevanjem materialov in pri tem uporabljenih tehnik) z odkritimi indikacijami in njihovimi velikostmi. Rezultati so bili osnova za izvedbo analize – medsebojno primerjavo občutljivosti posameznih kakovostnih neporušitvenih metod in najprimernejše tehnike za kontrolo kakovosti za posamezne materiale. Ugotovitev raziskave je, da je – ne glede na material – za pregledovanje kakovosti materiala najprimernejša magnetna metoda, pri kateri se uporablja tehnika s fluorescentnimi delci, čeprav lahko z njo zaznamo tudi nerelevantne indikacije. Zaradi tega je poleg nje priporočljiva še uporaba penetrantske metode, da izločimo lažne indikacije. Ugotovila sem tudi, da je penetrantska metoda občutljivejša pri okroglih indikacijah, kot so pore, za odkrivanje razpok pa je najprimernejša magnetna metoda.The work is based on a comparison of the sensitivity of non-destructive methods in order to assess surface quality of various materials - steel. It describes three quality methods for examining materials and products. These are welds, forgings and castings. The first and the most general method is visual control. It requires a "good" eyesight which must be checked by using the Jaeger test, Landolt and Ishihara charts. For the second detection technique we use penetrants. These are special substances which are applied on the surface of material. They penetrate into depth to fill irregularities that show indications by using a developer. For the third technique special magnetic pieces are used in order to detect locations and the size of indications with magnetic field. The original naming of the technique is "Technique with magnetic particles". It is important to refer to standards with all the techniques. These standards regulate quality levels and limit values for indications. I have used all the methods for research on two different materials. The first is a special constructional steel S355 and the second one is tool steel 42CrMo. All the methods and five inspection techniques have been applied on both materials. In the first phase, I examined both samples with visual technique and displayed the size of all indications. I continued by using red colored and fluorescent penetrant. I had some problems with the third method because I found out that the sample could not be magnetized in the same way. The structural steel had a shape of a symmetrical weld and the forging which was made of tool steel was in the form of a profile. It was necessary to use the technique of magnetic particle yoke for welding and for forging I used a magnetizing machine with contact plate and a coil. When the problem was solved the technique with black and fluorescent particles was used. The results that I wrote down were the basis for carrying out the analysis - a comparison of the sensitivity of individual quality methods and the most appropriate quality technique for individual materials. The final result of the study is that the best quality scanning method is the magnetic method with fluorescence particles for both materials. Because of the sensitivity of the method we can also find irrelevant indications. For this reason, it is advisable to use a penetrant method to eliminate false indications. I have also found out that the penetrant method is more sensitive to circular indications and the magnetic quality method is most suitable for cracks

Influence of Ageing and Deterioration of Masonry on Load Bearing Capacity of Historical Building

Numerous heritage buildings in the former Eastern Europe that were neglected in the past are severely deteriorated due to ageing and moisture problems. The paper summarizes experimental and numerical work carried out on 150 yrs. old Kolizej Palace in Ljubljana (Slovenia) which has recently been demolished, despite the overall opinion among conservators that it should be preserved. Experimental tests proved almost completely saturated conditions in the ground level of the building, while all the stories above were in almost dry condition. The results of tests on masonry revealed that moisture content and state of deterioration affected both strength and stiffness properties of built masonry in that extend so that the previous estimations and calculations regarding the state of the structure and its static load bearing capacity were too optimistic. Both storey and global response non-linear seismic analysis have proved that building in its current condition is far below the current seismic code requirements

Calculation and visualization of the object movement along great circle and rhumb line

Ortodroma in loksodroma sta krivulji na Zemlji, katere obliko obravnavamo kot kroglo. Ortodroma je del velikega kroga in predstavlja najkrajšo razdaljo med točkama. Loksodroma je od ortodrome daljša, vendar meridiane seka pod enakim kotom, zato pri gibanju ni potrebno spreminjati smeri gibajočega se objekta. V diplomski nalogi predstavljamo značilnosti krivulj in postopke numeričnega reševanja situacij na posameznih krivuljah. Kot rezultat naloge predstavljamo program v okolju MATLAB, ki ob vnosu geografskih koordinat dveh poljubnih krajev na Zemlji izračuna koordinate krajev na ortodromi in loksodromi ter omogoča vizualizacijo rešitev na karti Mercatorjeve projekcije in v Google Earth-u.Great circle and rhumb line are the curves on Earth, whose shape is treated as a sphere. Great circle is a part of a large circle and represents the shortest distance between the points. Rhumb line is longer than the great circle, but it crosses every meridian under the same angle, so meanwhile moving, direction change of the moving object is not needed. In the graduation thesis we present the characteristics of the curves and procedures of numerical solving for the situations on individual curves. As a result of the task, we present a program in the MATLAB environment, which, when entering the geographical coordinates of any two places on Earth, calculates the coordinates of places on the great circle and rhumb line, and allows the visualization of results on the Mercator projection map and in Google Earth

Analysis and design of a multi - storey office building in Celje

The thesis analyses the load bearing structure of an existing multi storey office building in Celje. The\ud load bearing structure is made of reinforced concrete, based on strip and isolated foundation footings,\ud slabs, columns and walls. It is analysed with the programme Tower7, which utilises the final elements\ud method. Two computational models of the load bearing structure are built. The first one is used to\ud analyse the typical ceiling construction in the building. Besides the slab, we also include some vertical\ud load bearing elements above and below the slab into the model. To analyse the vertical load bearing\ud elements we create a more complex three-dimensional computational model of the whole load bearing\ud construction. The ceiling slab analysis takes into account both the dead load as well as the live load.\ud The analysis of the whole load bearing structure also includes snow load and the horizontal effects of\ud wind and earthquake. The dynamic effect is determined by the means of a linear modal analysis with a\ud response spectrum. The core of the thesis is represented in the analysis and the dimensioning of typical\ud load bearing elements in the building. Firstly, dimensioning of the lower and upper reinforcement is\ud executed. The calculation results are compared to the amount of built-in reinforcement, information\ud about which is gathered from the original project documentation that followed the old PBAB\ud regulation. Next, is the dimensioning of wall AB and column AB. The reinforcement for both is\ud constructed in accordance with ductile behaviour requirements. The results show that the existing wall\ud and column reinforcements only partially satisfy the requirements of evrokod regulations currently in\ud place

»Tuji govor« ter razmerje med lingvistiko in pragmatiko

Razzprava izpostavi epistemološka vprašanja, ki zastavljajo, če skušamo artikulirati bahtinovsko problematiko tujega govora v znanostih o jeziku. Osredotoči se na vidikih, ki problematizirajo neopozitivistično formulacijo razmerja med semantiko in pragmatiko

Znanstveni predmet sociologije kulture

This article outlines the scientific object of the sociology of culture. The starting points are two intuitive objects of this discipline: the cultural sphere as it presents itself to naïve observation, and the methodologically motivated notion that culture/consciousness is the constitutive aspect of all social phenomena. The article attempts to produce a dialectical synthesis of these opposing positions. It starts with Marcel Mauss’s “total social fact,” the notion that every social fact is a unity of structure and representation. However, to explain the “cultural” phenomena, the sociology of culture must be able to grasp the specificity of those total social facts that also function as representations in relation to other, “non-cultural” social facts. Such ideological practices or forms of consciousness are its true object. The article goes on to establish the criteria for classifying the ideological and the material social facts as parts of the Marxian base or superstructure. It argues that the formal criterion – type of social relations – is necessary and sufficient for determining to which mode of production a certain material practice belongs. The formal criterion, though, is not sufficient when it comes to ideological practices: from the formal viewpoint, many ideological practices belong to the base of the capitalist mode of production. However, because of their function, they must also be analysed as parts of its superstructure