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När Eurokod 5, standarden för dimensionering av träkonstruktioner, infördes i Sverige sågjordes det även en sänkning av hållfasthetsvärden för trä vid tryck vinkelrätt fibrerna.Tidigare kapacitet på 8 MPa för limträklass L40 var nu för högt, och den av SverigesTekniska Forskningsinstitut (SP) reviderade CE L40c fick en kapacitet på 2,7 MPa. Ettproblem i och med detta blev att byggnader som är konstruerade och uppförda enligtBoverkets föreskrifter inte längre kan utformas på samma sätt sedan Eurokodernasinförande. Syftet med arbetet blev därför att:• Ta reda på varför sänkningen skedde• Ta fram några räkneexempel på hur man kan åtgärda för låg kapacitet vid tryckvinkelrätt fibrernaLitteraturstudien som ligger till grund för arbetet visar på att sänkningen skedde på grund avatt Eurokodernas provmetod för bestämning av hållfastheten skiljer sig från den metod somBoverket använt. Den stora skillnaden ligger i att Eurokoderna inte utnyttjar lastspridning iträ, där lasten kan spridas från en träfiber till en annan intilliggande och på så vis öka denfaktiska kapaciteten. Det kan också nämnas att själva dimensioneringsprocessen inte har likastor betydelse som hållfasthetsklassningen.De beräkningar som gjordes i enlighet med arbetets andra syfte visar lämpligaförstärkningsåtgärder vid upplaget. De tre förstärkningsåtgärder som har undersökts är:• Stålplåt som läggs mellan pelare och balk för att på så vis utöka upplagslängd ochdärmed sprida upplagstrycket• Stålskruvar som skruvas in vid upplaget, tvärs fibrerna i balken• Trästavar som limmas in vid upplaget, tvärs fibrerna i balkenAlla beräkningar utfördes med 100 kN last, balktvärsnitt på 215x630 mm, pelartvärsnitt på215x150 mm och upplagslängd 150 mm.• Då stålplåtens bredd var 215 mm och med stålkvalitet s235 erhölls enligt beräkningaren plåttjocklek på15 mm och en plåtlängd på 270 mm för att klara avdimensionerande last.• För 6 st stålskruvar M12 4.6 och penetrationsdjup 400 mm erhölls enligt beräkningaren ny karakteristisk kapacitet på 5,6 MPa.• För 6 st trästavar av björk, 19 mm diameter och penetrationsdjup 400 mm erhöllsenligt beräkningar en ny karakteristisk kapacitet på 5,07 MPa. / When Eurocode 5, design rules for timber structures, was introduced in Sweden there wasalso a reduction in strength values for structural timber, and especially when it comes tocompression perpendicular to the grain. Earlier on, before Eurocode 5, the capacity ofScandinavian glulam L40 was 8 MPa which now was to be revised by the Technical ResearchInstitute of Sweden (SP). The new value was set to 2.7 MPa and the new revised glulam wasnamed CE L40c. A problem now arose, namely so that existing structures (which aredesigned after the old Swedish standard BKR) no longer can be designed in the same way.The purpose of this thesis was to:• Find out why the reduction in capacity for compression perpendicular to the grainoccurred• Make a few examples through calculations on how to fix this problemThe studies of literature which this thesis is based upon indicates that the reduction incapacity was due to the very nature of how the Eurocodes determines the strength classes,and how it is different from BKR. The big difference is that in the Eurocodes there is noutilization of the physical phenomenon where the loaded wood fibres distributes the load to anearby unloaded fibre. This phenomenon greatly increases the capacity at compressionperpendicular to the grain. It should be mentioned that this work also indicates that thedesign process does not have the same impact on the design of structures as the grading ofstrength classes has.According to the second purpose of this thesis, a set of calculations were made whichindicates appropriate methods of reinforcement of a wooden beam. The three methods are:• A steel plate which is placed between a column and a beam to increase the supportlength and therefore spread the support stress over a larger area of the beam• Steel screws which are screwed into the beam at the support, perpendicular to thegrain• Wooden rods which are glued in place inside the beam at the support, perpendicularto the grainAll calculations were made with a load of 100 kN, cross section of the beam is 215x630 mm,cross section of the column is 215x150 mm and support length is 150 mm.• When the width of the steel plate is 215 mm and steel grade s235 is used, the steelplate dimensions required are, according to calculations, thickness of 15 mm andlength of 270 mm.• With 6 steel screws, M12 4.6 and a penetration depth of 400 mm, a new characteristiccapacity of 5.6 MPa was obtained.• With 6 wooden rods made out of birch, 19 mm diameter and a penetration depth of400 mm, a new characteristic capacity of 5.07 MPa was obtained.

Till grund för detta examensarbete ligger en ineffektiv process, samt dubbelarbete som idag utgör arbetsgången vid CAD-projektering för konstruktörer hos Structor i Karlstad. Målet med examensarbetet är att genomföra en kompatibilitetskontroll av 3D-modelleringsprogrammet Tekla Structures 15.0 mot analys- och beräkningsprogrammen Autodesk Robot Structural Analysis Professional 2010 samt Strusoft FEM-Design. Syftet är att med hjälp av kompatiblitetskontrollen utgöra vilket av programmen Autodesk Robot och FEM-Design som bäst lämpar sig att köras tillsammans med Tekla Structures utifrån valda faktorer. Två äldre examensarbeten används för att få en uppfattning om FEM-Design.   För att undvika det omfattande och tidskrävande arbetet med att skapa två modeller, en grafisk samt en analytisk modell, finns en lösning. Genom att skapa den grafiska modellen i Tekla Structures 15.0, vilket sedermera genererar den analytiska modellen, och sedan exportera den via länk till Autodesk Robot Structural Analysis 2010 behövs bara en modellering. Ett arbetsmoment, som förut inneburit ytterligare en modellering i analysprogrammet, undviks härmed. Medveten modellering, det vill säga kontinuerlig kontroll av den analytiska modellens utseende i Tekla, krävs för mest fördelaktiga resultat. Detta bör finnas i åtanke under hela arbetsprocessen. Det är i slutändan alltid projektören/konstruktören som styr hur Robot i sin tur kommer att behandla modellen som skickas från Tekla.   Laster och lastkombinationer går att justera i både Tekla och Robot. Dock anses det, för en van Teklaanvändare, vara smidigast att hantera detta i Tekla. Om detta sker i Tekla behövs ytterligare inställningar i Robot aldrig göras. Robot utför då endast analysen och bearbetar de resultat som analysen utgör. De resultat som återfinns går att behandla i Robot och redovisas på sätt som är relevanta för respektive användare. De grundläggande resultaten, så som största påverkande moment och tvärkraft, går att importera tillbaka till modellen i Tekla och hamnar då under respektive profils attributinställningar.

Detta examensarbete behandlar STT/F-bjälklagselementens krympning och krypning. Arbetet har utförts på uppdrag av Strängbetong AB, med Örjan Pettersson som initiativtagare och handledare. STT/F-bjälklagselement är en prefabricerad förspänd betongprodukt bestående av två spända balkar med en ovanpåliggande armerad platta. De används som bjälklag i yttertakskonstruktioner och har, tack vare tunna balkliv och en sadelformad platta, låg vikt och kan uppnå spännvidder närmare 30 meter. Förspända element förändras efter gjutning på grund av krympning, krypning samt stålets relaxation. Förutsättningarna varierar med bland annat olika betongkvalitet, förspänningsnivå, temperatur och luftfuktighet. Vid dimensionering tas hänsyn till dessa parametrar för att säkerställa maximal spännvidd och upplagslängd. Syftet med detta examensarbete har varit att jämföra bjälklagselementens verkliga förändringar med de beräknade. På Strängbetongs fabrik i Kungsör har mätningar utförts under olika årstider med varierande luftfuktighet och temperatur. Rörelsen samt överhöjningen hos elementen har noterats; först i form före gjutning och därefter under lagring, för att sedan jämföras med beräkningar enligt den gemensamma europeiska beräkningsstandarden Eurocode 2. Vid krypningsberäkningar har Strängbetongs beräkningsprogram för betongelement SbEle 3.10 delvis använts. Vid jämförelse, efter avslutade mätningar och beräkningar, kan fastställas att de uppmätta värdena överensstämmer väl med de beräknade vad gäller rörelsen. 0,5 + 0,5 promille är rimliga värden att anta på autogen respektive uttorkningskrympning. Överhöjningen är jämförelsevis också väl överensstämmande, med undantag för två av bjälklagselementen med en högre spänningsnivå. Eurocode 2 kan anses vara fullt tillämpbart som beräkningsmetod för STT/F-bjälklagselement.

The design regulations of Boverket (BKR) have long been the mandatory standard for construction design in Sweden. However from the end of the year 2010, the BKR will be replaced by the European standard Eurocode (EC). The transition to EC has been delayed and it is not until the second of May 2011 that the use of EC will be mandatory. Because EC and BKR differ from each other it is highly interesting to investigate and explain these differences. The purpose of the thesis is to compare the two standards and investigate how they give different results or not for the dimensioning of structures of steel with associated loads. The current project HVC (Pets Science Center) in Uppsala is used as a model for the design of the steel structure used in this study. The investigation is divided into two parts: the calculation of loads and the dimensioning of the steel structure. The internal forces in the construction that are used for the dimensioning are calculated with finite element programs (FEM-programs). The calculations for the comparison of the dimensioning of the steel structure are thereafter calculated by hand according to the current standard of each. Eurocode 3 (EC 3) is the current standard for EC and for BKR the current standard is the handbook for steel structures (BSK 07). The compared parts are: •the control of flexural buckling of a framework brace towards compression force and bending, •the control of a framework brace towards tension force and bending, •the control of a column against compression by a pure normal force, •and the control of a welded joint between a framework brace and an underlying beam. The results from the dimensioning are presented separately in the report and show that in almost all cases of design a lower grade of utilization is obtained for EC 3 than BSK 07. The largest obtained difference is when the dimensioning of a framework brace towards compression force and bending is made there the relationship between the utilization rates are 0,80. The results show that dimensioning according to EC 3 probably will lead to decreased costs within the construction sector, mainly in materials because smaller dimensions are required.

The aim of this study is designing steel structures with the same geometry, material and soil conditions but in the different countries, and comparing these designs in terms of material savings. According to three steel building codes, namely TS 648, LRFD, Eurocode 3, same structures with various stories (2, 4, 6, 8, and 10) are analyzed and designed. To calculate the design loads, Turkish Earthquake Code 2007 and Turkish Standard 498 (Design Load for Buildings) are utilized when TS 648 is applied. When LRFD is concerned, ASCE Standard 7-05 (Minimum Design Loads for Buildings and Other Structures) and AISC Standard 341-05 (Seismic Provisions for Structural Steel Buildings) are used for calculation of the design loads and earthquake loads. When Eurocode 3 is applied, Eurocode 8 (Earthquake Resistance Code), Eurocode 1 (Actions of Structures) and Eurocode-EN 1990 (Basis of Structural Design) are used in order to determine the design and earthquake loads. Weight of steel used on 1 m&sup2 / is almost the same for procedures of LRFD and EC3. It is important to note that those procedures consider 20 % of material saving compared to TS648.

Αντικείμενο της παρούσας εργασίας αποτελεί η αποτίμηση της σεισμικής ικανότητας ενός πολυώροφου κτηρίου από φέρουσα τοιχοποιία που βρίσκεται στην Κέρκυρα, μέσω προγράμματος πεπερασμένων στοιχείων. Στο πρώτο μέρος της εργασίας, παρουσιάζονται γενικά στοιχεία όσον αφορά τη φέρουσα τοιχοποιία. Πιο συγκεκριμένα γίνεται αναφορά στην παθολογία κτηρίων από φέρουσα τοιχοποιία εστιάζοντας στα βασικά είδη ρωγμών που εμφανίζονται σε τέτοιου είδους κτήρια. Στη συνέχεια, γίνεται αναφορά στον προσδιορισμό των μηχανικών χαρακτηριστικών της τοιχοποιίας μέσω εξισώσεων του EC6. Γίνεται εκτενής αναφορά σε μια προσεγγιστική μέθοδο προσδιορισμού των εντατικών μεγεθών της φέρουσας τοιχοποιίας, της Μεθόδου των Πεσσών, αναφέροντας επίσης και τη μέθοδο που ακολουθείται για τον έλεγχο των διατομών της τοιχοποιίας διαθέτοντας τα συγκεκριμένα εντατικά μεγέθη. Επίσης, αναφέρονται αναλυτικά τρεις μέθοδοι ελέγχου των διατομών φέρουσας τοιχοποιίας , με τις εξισώσεις του EC6, που χρησιμοποιούνται εμμέσως στο πρόγραμμα ECTools, με τις εξισώσεις του Εθνικού Κειμένου Εφαρμογής του EC6, και από κατάλληλη βιβλιογραφία. Ακόμη, γίνεται αναφορά στα όρια του ΕC8 για τις μετακινήσεις των τοίχων σε τέτοιου είδους κτήρια. Τέλος παρουσιάζεται η διαδικασία του δευτεροβάθμιου προσεισμικού ελέγχου για την εύρεση της ανεπάρκειας ενός κτηρίου H/R. Στο δεύτερο μέρος της εργασίας παρουσιάζονται όλα τα στοιχεία που εισήχθησαν στο πρόγραμμα των πεπερασμένων στοιχείων για τη δημιουργία του κατάλληλου προσομοιώματος. Πιο συγκεκριμένα, αρχικά γίνεται πλήρης αναφορά των γεωμετρικών στοιχείων του κτηρίου σύμφωνα με τα σχέδια αποτύπωσής του, τα οποία επίσης παρουσιάζονται. Στη συνέχεια γίνεται πλήρης και αναλυτικός υπολογισμός των μηχανικών χαρακτηριστικών της τοιχοποιίας σύμφωνα με κατάλληλη βιβλιογραφία. Αναφέρεται επίσης ο τρόπος με τον οποίο έγινε η επιλογή των κατάλληλων φορτίων και παρουσιάζεται η διαδικασία με την οποία έγινε ο διαχωρισμός των πεπερασμένων στοιχείων του προσομοιώματος. Η δεύτερη ενότητα ολοκληρώνεται με την λεπτομερή αναφορά στο τρόπο διαχωρισμού πεσσών και ανωφλιών της φέρουσας τοιχοποιίας. Στο τρίτο μέρος της εργασίας παρουσιάζονται τα αποτελέσματα της ανάλυσης του κτηρίου με τα προγράμματα Etabs και ECTools αλλά και λογιστικών φύλλων Excel όπου απαιτήθηκε σύγκριση αποτελεσμάτων μέσω χρήσης εξισώσεων και προγράμματος αντίστοιχα. Αρχικά, παρουσιάζονται τα αποτελέσματα συγκεκριμένων ελέγχων που γίνονται στο υφιστάμενο κτήριο μέσω των εξισώσεων του Ε.Κ.Ε. Στη συνέχεια, και αφού παρουσιασθούν όλοι οι υπολογισμοί των ανεπαρκειών για όλες τις μορφές ελέγχου, γίνεται σύγκριση των αποτελεσμάτων της πρότασης που έγινε σε κατάλληλη βιβλιογραφία το 2007 και του ECTools με βάση το βαθμό ανεπάρκειας. Ακολούθως, παρουσιάζονται υπό μορφή χρωματικών κλιμάκων τα αποτελέσματα των μετακινήσεων τριών παραλλαγών του προσομοιώματος του κτηρίου (ανάλογα με την παρουσία ή μη των διαφραγμάτων), τα οποία προκύπτουν για συγκεκριμένους συνδυασμούς δράσεων στις δύο διευθύνσεις δράσης του σεισμού. Επίσης εξάγονται κάποια συμπεράσματα που βασίζονται όχι μόνο στην τιμή της μετακίνησης σε κάθε προσομοίωμα αλλά και στη θέση που εμφανίζεται αυτή. Ακόμη, γίνεται μία απόπειρα να προσομοιωθεί ελλιπής σύνδεση δύο τοίχων έτσι ώστε να συγκριθούν με τα αποτελέσματα της πλήρους σύνδεσης, όχι μόνο οι μετακινήσεις αλλά και οι ανεπάρκειες που προκύπτουν για τα δύο προσομοιώματα αντίστοιχα. Ακόμη μία διερεύνηση γίνεται παρουσιάζοντας τις τάσεις που προκύπτουν για συγκεκριμένους συνδυασμούς φορτίσεων και υπολογίζοντας τις ανεπάρκειες που προκύπτουν σε όρους τάσεων σε συγκεκριμένες περιοχές του κτηρίου που επιλέχθηκαν. Στη συνέχεια, εφαρμόζεται η Προσεγγιστική Μέθοδος των Πεσσών για τον υπολογισμό των εντατικών μεγεθών και ακολουθεί σύγκριση των ανεπαρκειών που προκύπτουν μέσω συγκεκριμένων εξισώσεων από αυτά τα εντατικά μεγέθη και τα αντίστοιχα που προκύπτουν από το πρόγραμμα Etabs. Ακόμη, γίνεται σύγκριση των μετακινήσεων εκτός επιπέδου που προκύπτουν για συγκεκριμένο συνδυασμό φόρτισης και των ορίων που ορίζει ο Ευρωκώδικας 8 για κάμψη και αξονική δύναμη και για διάτμηση αντίστοιχα. Αφού προσδιορισθούν και τα όρια των μετακινήσεων υπολογίζονται οι ανεπάρκειες σε όρους μετακινήσεων, μέσω των γωνιακών παραμορφώσεων. Ακολουθεί η εύρεση του δείκτη ανεπάρκειας του κτηρίου Η/R μέσω της διαδικασίας δευτεροβάθμιου προσεισμικού ελέγχου. Αφού γίνει ο υπολογισμός αυτός, ακολουθεί η σύγκριση του δείκτη αυτού με τη μέγιστη τιμή της ανεπάρκειας πεσσού που προέκυψε από τις εξισώσεις του EC6, και της μέγιστης τιμής σε όρους μετακινήσεων. Ακολουθεί, επίσης, σύγκριση της ανεπάρκειας αυτής με το μέσο όρο των ανεπαρκειών των πεσσών και τον αντίστοιχο μέσο όρο σε όρους μετακινήσεων. Ακολούθως, πραγματοποιείται η διόρθωση των δεικτών Η/R σύμφωνα με τις ανεπάρκειες του EC6 και του EC8. Στην επόμενη ενότητα ακολουθεί μια παραμετρική διερεύνηση της μείωσης του πλήθους των ορόφων του κτηρίου. Αρχικά εξετάζεται η περίπτωση 4 ορόφων και συγκρίνεται με τα αποτελέσματα των ανεπαρκειών σε 6όροφο κτήριο και στη συνέχεια παρόμοια διαδικασία ακολουθείται για την περίπτωση 2 ορόφων. Η τελευταία ενότητα της διατριβής αφορά την περίπτωση των «απλών» κτηρίων από φέρουσα τοιχοποιία και τη διερεύνηση με συγκεκριμένες παραμέτρους της ασφάλειας των ισχυόντων διατάξεων για την απαλλαγή από στατικούς υπολογισμούς συγκεκριμένων κτηρίων από φέρουσα τοιχοποιία. Επίσης, παρουσιάζεται μέσω της ανάλυσης του 6ώροφου κτηρίου αλλά και των παραλλαγών του (4ώροφου και διώροφου), και αντίστοιχα των “απλών” κτηρίων (μονώροφων και διώροφων), η διαφορά του δείκτη H/R σε χαμηλώροφα και υψηλώροφα κτήρια μα βάση τις ανεπάρκειες που προέκυψαν από τον EC8. Στόχος της συγκεκριμένης διατριβής είναι αρχικά, η διερεύνηση, μέσω των υπολογισμών των ανεπαρκειών σε κτήρια από φέρουσα τοιχοποιία, της επιρροής κάποιων συγκεκριμένων παραμέτρων στις ανεπάρκειες του κτηρίου. Επίσης, διερευνάται η εξιοπιστία του δείκτη ανεπάρκειας που προκύπτει από δευτεροβάθμιο προσεισμικό έλεγχο μέσω της σύγκρισής του με τις ανεπάρκειες που προκύπτουν από τον EC6 και τον EC8. Τα συμπεράσματα που προκύπτουν σχετικά με τη διόρθωση του τρόπου υπολογισμού του δείκτη αυτού είναι ιδιαιτέρως ενδιαφέροντα και παρουσιάζονται στο τελευταίο μέρος της διατριβής. / The object of this master thesis is the assessment of seismic behavior of a multistory masonry building in Corfu, Greece, through a program of finite elements. In the first part of the project, general information for masonry structures is referred, such as the basic cases of cracks that appear in such buildings. Moreover, the mechanical characteristics of masonry are defined through equations of EC6, and an approximate method of defining these characteristics is presented. Furthermore, three methods of assessment of masonry sections through Eurocode 6, that are used by ECTools, National Annex of Eurocode 6 and specific bibliography. Then, the method of Eurocode 8 that uses deformations and drifts as means of defining damage index. Finally, an approximate assessment method of the Greek Earthquake Planning and Protection Organizations is presented. In the second part of the project, the input of the program is presented for the creation of a suitable simulation. Firstly, the geometrical input of the building are presented, as well as the computation of mechanical characteristics of masonry. Finally, in the second part of the project a method of the separation of piers and spandrels is carried out. In the third part of the project, the results of analysis of the building is carried out through Etabs, ECtools and Excel. Firstly, the results of particular checks in an existing building through equations of National Annex are presented. The same checks are carried out through a process that is proposed by a project of 2007 and through ECtools, so that a comparison between the last two is carried out. Moreover, the results of displacements are presented through contours and according to the presentation of diaphragms in the simulation of the building, or not. Some conclusions are carried out through this process, that are based not only on the displacement, but also in the position of this displacement. An attempt so that an incomplete combination of two walls is simulated is carried out and through that, a compare between the results of damage index of this simulation and the results of complete combination of walls is presented. Moreover, the damage index through stresses is carried out in particular parts of the building. Then, an approximate method of piers is applied so that a computation of moments and shears is carried out. Using these results and that of the program Etabs, a compare of the damage index that is the result of these methods is carried out. Moreover a compare between the displacements of out of level and the limits of Eurocode 8 for shear and bending is presented. The computation that follows concerns the damage index H/R through the process of the Greek Earthquake Planning and Protection Organizations. Following all these, a compare between the mean value of damage index through Eurocode 6 and the maximum value of Eurocode 8 is carried out and according to these the values of H/R are corrected. In the next part of the project a parametric study of the number of stories of the building is carried out and some serious results are carried out. The last part of the thesis concerns “simple” masonry buildings that are not engaged to be designed. Moreover, the difference between the damage index H/R in multistory buildings and low-story buildings is carried out basing in the damage index of Eurocode 8. The goal of this thesis is, firstly the influence of some parameters in the damage index of a building. Moreover, the validation of the damage index H/R is investigated through the damage index of Eurocode 6 and 8. The conclusions that are carried out concerning the correction of the method of computation of damage index, are very interesting and are presented in the last part of the project.

At the beginning of 2011, Sweden started using the European rules for structural design, the Eurocodes, instead of the previous national rules. In both the previous rules and the Eurocodes, it is possible to dimension concrete columns using tabled values. However, the required cross section measurements have increased considerably. Moreover, it is possible to dimension concrete columns using calculations, however, this is unusual. The development of a fire in a fire cell can be divided into the growth stage, the fully developed fire and the cooling phase. The duration of each phase, as well as the temperature, is dependent on a number of factors, e.g. the fire load, the size of openings and the geometry of the fire cell. In the Eurocodes there are standardized temperature-time curves that can be used in the dimensioning of a structural design, one of which is the standard temperature-time curve. The tabled values are based on this time-heat regime. When exposed to fire the strength of both concrete and reinforcements decreases. Regarding the reinforcement steel, the decrease is well documented. Concrete, however, is not a homogeneous material which makes the strength at elevated temperatures complex to determine. The dimensioning of concrete columns can be executed using tabled values. However, the objective of this report is a method called the 500 °C isotherm method. Using this method, concrete at temperatures above 500 °C is assumed not to contribute to the load bearing capacity. The residual cross-section retains its initial value of strength and modulus of elasticity. This results in a reduced cross-section. Subsequently, a reduced load bearing capacity is determined for the reinforcement steel due to the temperature. Thereafter, conventional calculation methods are used. The process of describing how the isotherm method should be implicated has been obstructed by the lack of explicit information in the Eurocodes. Furthermore, few people have knowledge about how the method should be used in practice. This has resulted in some assumptions based on logical arguments. A concrete column was evaluated for 60 and 90 minutes standard fire exposure to enable a comparison with the tabled values. The result showed that concrete columns can meet the requirements with a considerably smaller cross section. The calculated cross section measurements resulted in a value between the tabled values in the Eurocodes and those in the previous rules. Although the 500 °C isotherm method is the most simple of the simplified calculation methods, and the model in this report is limited to a circular, centrically loaded column, the method is complicated and time-consuming. It is therefore likely that it only will be used in special cases when the tabled values are inapplicable. / Vid årsskiftet 2010-2011 övergick Sverige från nationell standard till de europeiska standarderna för konstruktion, Eurokoderna. I den europeiska standarden, precis som i den gamla, kan betongpelare förenklat branddimensioneras med hjälp av tabellvärden. Kraven på minsta tvärsnitt har dock blivit avsevärt större. Detta har varit blivit svårt att förena med önskemål från arkitekter. Det är även möjligt att branddimensionera betongpelare med beräkningar. Detta är dock ovanligt. Brandförloppet i en brandcell kan förenklat delas in i uppvärmning, fullt utvecklad brand och avsvalning. Tiden för de olika faserna, liksom temperaturen, påverkas av en mängd faktorer. Några av dessa är mängden brännbart material, hur stora öppningar som finns och brandcellens geometri. I Eurokoderna finns standardiserade brandförlopp som kan användas vid dimensionering. En av dessa kallas standardbrandkurvan. Tabellvärdena är baserade på standardbrandpåverkan. Vid branddimensionering används en annan lastkombination än vid normaltemperaturdimensionering. Denna lastkombination ger en lägre last än vid brottgränsdimensionering. Både betong och armeringsstål förlorar bärförmåga vid förhöjda temperaturer. För armeringsstål är denna reducering väl dokumenterad. För betong, som inte är ett homogent material, är hållfastheten svårare att beräkna. Betongpelare kan dimensioneras enligt tre metoder: Vedertagna och beprövade detaljlösningar (Tabellerade värden) Förenklade beräkningsmetoder Avancerade beräkningsmetoder Fokus i denna rapport ligger på en av de förenklade beräkningsmetoderna, 500 °C isotermmetoden. Den utgår från att betong som har en temperatur över 500 °C försummas, emedan betong med en temperatur under 500 °C antas ha sin fulla bärförmåga. Därefter beräknas en reducerad hållfasthet för armeringsstängerna utifrån den temperatur de uppnår. Dimensionering sker sedan enligt traditionella metoder. Arbetet med att beskriva hur isotermmetoden ska användas har försvårats av bristande information i Eurokoderna. Dessutom finns det få personer som känner till hur metoden ska användas i praktiken. Detta har resulterat i vissa antaganden som underbyggts av logiska resonemang. För att kunna jämföra isotermmetoden med tabellerade värden kontrollerades en pelare för 60 och 90 minuters standardbrandpåverkan (se Bilaga A). Resultatet visade att pelare kan klara kraven med mindre tvärsnitt än i tabellen. Vid dimensioneringen erhölls ett tvärsnitt som låg mellan de nya och de gamla kraven. 500 °C isotermmetoden är den enklaste av de förenklade beräkningsmetoderna för betongpelare. Detta innebär dock inte att den är enkel. Trots att modellen i denna rapport har avgränsats till centriskt belastade, cirkulära pelare är metoden tidskrävande. Troligt är därför att den bara kommer att användas vid speciella fall då tabellmetoden inte är tillämpbar.

This thesis approaches the problem of the cost-efficient wind turbine foundation on an onshore site of clayey soil characteristics. The given soil stratigraphy includes a layer of clay and two sands of different density. The characteristics of the soil and the water level that were used as input come from a site in Peloponissos, Greece. The applied wind, static and seismic loads on this study were resolved with the German DIN standards, and other related research and European standards. The safety factors were adjusted for wind turbines. For the pile solution, after the bearing and overturning adequacy against the horizontal and vertical loads was proven with the calculation of the DIN equations, then the model was inserted in the Pfahl program using DIN 4017 equations to calculate settlements. Firstly, a shallow foundation of various dimensions in the clay layer over the water level with all the necessary checks was considered. Afterward, a deep foundation solution of a single bored pile, with reinforcement steel casing, of various diameters was investigated. The different foundation solutions were assessed and compared on a technical and economic basis. As a conclusion, the 0.70 meter diameter single pile was chosen as the best solution because it needs only a few days for construction, and it is the most cost-efficient. The chosen circular footing was of a diameter of 10 meters and 1.5 meter raft thickness, but proved unfeasible because of high excavations costs. The checks on the DIN standards and Eurocode that set the boundaries for the design in the two cases were recognised and possible future work goals were discussed.

Tanks are storage vessels for liquids. They can have different appearances; some are short and wide, others are tall and slim, some are small, others are large. In this thesis a tank of 6 m in both diameter and height has been used to obtain numerical results of the stresses in the tank. Tanks are most often thin-walled with stepwise variable shell thickness with thicker wall sections at the bottom of the tank and thinner at the top. Since they are thin-walled they are susceptible to buckling and there are conditions the shell construction must meet. The conditions that has to be met are determined by the laws and regulations that govern tank design. The National Board of Housing, Building and Planning (Boverket) is the new Swedish authority for rules of tank design and the Eurocodes are the new family of standards that should be followed. Sweco Industry AB is the outsourcer of this thesis and wants to clarify what rules that apply now when the Eurocodes are to be followed. The thesis project has produced a calculation document in Mathcad for tank shell design according to the Eurocodes with stress calculations according to membrane theory and linear elastic shell analysis. This thesis has also produced a comparison of stresses calculated using membrane theory, linear elastic shell analysis and finite element method (FEM). The comparison has been made for numerical results given for an arbitrarily designed tank wall. The loads acting on the tank included in the description were self-weight, internal and hydrostatic pressure as well as wind and snow loads. The loads were described in accordance with the Eurocodes. Some assumptions had to be made where the standard was vague or deficient in order to make calculations by hand possible. For example, the wind load had to be described as an axisymmetrically distributed load rather than an angularly varying. The stresses in the tank wall were calculated through creating free-body diagrams and declaring equations for force and moment equilibrium. The loads and boundary conditions were set in a corresponding manner in the FEM software Ansys as in the calculation document in order to obtain comparable results. When compared, the stress results calculated with membrane theory and FEM were quite similar while the stresses calculated with linear analysis were a lot larger. The bending moments were assumed to be too large which make the results of the linear analysis dominated by the moments. The arbitrarily dimensions set for the tank did thus not fullfill the conditions when linear analysis was used but did so for membrane theory and FE-analysis. Since the results calculated with membrane theory were very close to FEM in most cases, even without expressions for local buckling, it was assumed to be an adequate method in this application. Expressions for local buckling are although needed for the meridional normal stress. The conclusions of the results obtained are that membrane theory is a simple and adequate method in most cases. Linear analysis thus becomes redundant since it is more complicated and more easily leads to faulty results. Furthermore it cannot be used for higher consequence classes than membrane theory. FEM, with a computer software such as Ansys, is although the most usable calculation method since it can conduct more complicated calculations and is allowed to be used for all consequence classes.