Genom att modellera bärverk med förskjutningsmetoden och programmera beräkningsprogram för takstolar i MS Excel har här visats att man kan uppnå motsvarande resultat som vanligt använda program i byggbranschen, baserade på förskjutningsmetoden. Resultaten visar på skillnader mellan förskjutningsmetoden och FEM. Det har dock inte framkommit om skillnaderna beror på grundläggande teorier i modellerna eller olika materialvärden i indata. / By learning how to model a structure by the direct stiffness method and programing a program for roof trusses in MS Excel have here by shown that you can achieve corresponding results as programs usually used in the building industry, based on the direct stiffness method. Results show differences between the direct stiffness method and FEM. It has not shown if the differences depends on fundamental theories in the models or disparities in material input.

Då Tarfalahallens tak kollapsade i Mars 2020 kallades den SvenskaHaverikommissionen in för att utreda bakomliggande orsaker tillraset. En av de primära orsakerna bakom raset var en vippad balk iden bärande takkonstruktionen. Takkonstruktionen utgjordes avunderspända takstolar, en konstruktion som på grund avHaverikommissionens utredning och påföljande anmälan tilltillsynsmyndigheten och Boverket skulle komma att bli ifrågasattgällande dess säkerhet. Byggnadsnämnderna i Sveriges kommunerfick 2020/2021 i uppdrag att undersöka om byggnader medunderspända limträtakstolar finns, byggs eller projekteras inomderas verksamhetsområde. Om så var fallet, raskt bedömastabiliteten i konstruktionerna, vidta nödvändiga åtgärder därinstabilitet upptäcktes samt rapportera alla fynd tillbaka tillBoverket.Då ledande svensk litteratur inom limträkonstruktion ej behandlarunderspända konstruktioner i någon större utsträckning fanns ettbehov av att se på vilka mekanismer som föranlederstabilitet/instabilitet för denna konstruktionstyp. Dettaexamensarbete ämnar försöka besvara dessa frågor och har genomen litteraturstudie sammanställt parametrar för stabilitet för dennakonstruktionstyp. Checklistor för initial stabilitetskontroll utifrånrelationshandlingar och inmätningsdata har tagits fram. Eninmätningsplan har skapats för att underlätta datainsamlingen förden initiala bedömningen. Ett förslag på ett övervakningssystemför konstruktionstypen har tagits fram och en bedömning avbefintliga takstolar har gjorts med hjälp av de checklistor somskapats under arbetets gång. Slutligen verifierades stabiliteten i detakstolar som kontrollerades genom en bärverksanalys enligtEurokod 5 och EKS 11 / In march of 2020 the roof of Tarfalahallen in Kiruna, Sweden,collapsed and the Swedish accident and incident investigationcommittee was called on site to investigate the causes for thestructural collapse. One of the primary reasons for the incident waslateral instability in one of the beams. The loadbearing constructionconsisted of underspanned beams. A construction type that cameinto question regarding its safety and practicality due to theinvestigations report and the following notification to thesupervisory authority. All Swedish municipalities were asked toinvestigate whether there were any buildings with thisconstruction type within their governing areas. If there were anyplans for constructing buildings with these roof systems or if anyunderspanned systems were in construction within their governingareas. If so, they were to investigate the stability of saidconstructions and take necessary precautions if instability wasfound and report back to the supervisory authority. Sinceinformation on underspanned, glue laminated timber structures,are scarce in leading Swedish literature there was a nedd to look atthe mechanisms behind what causes stability and instability withinthis construction type. The aim of this bachelor thesis is to try andanswer the questions regarding mechanisms behind stability andinstability for underspanned systems of glue laminated timber.This work also tries to answer the question regarding theconstruction-types safety and practicality. A literature study hasbeen performed to compile parameters regarding stability forunderspanned beams of glue laminated timber. Checklists havebeen produced to aid in the initial evaluation of stability. A planfor how to gather physical data through surveying has beenproduced for the initial evaluation. Lastly, an initial evaluation hasbeen performed on a set of underspanned beams with thechecklists produced in this thesis, a glue laminated timberstructure in Skellefteå, Sweden was evaluated. A loadbearinganalysis has been performed on the same set of beams inaccordance with Eurocode 5 and EKS 11 to verify the stability ofsaid beams. The indicators of stability from the initial evaluationwere confirmed by the loadbearing analysis. / <p>2022-06.21</p>

<p>The purpose with this report is to illuminate the construction solutions and the deformations that could exist in medieval parish stone churches. But also to increase the writers understanding how activity forces effect the construction of the churches. With help from literature and a practical study, containing three churches the writers have collected the material that the conclusions and discussions are built upon in this report. </p><p>The construction of the churches consists of three parts, the wall, the roof and the vault. The construction solutions are similar in the churches disregard of the roof, where the roof trusses are different. The roof trusses are yet typical for the roman style. The deformations that have been found can in most cases be could usual occurring in these old churches the writers chosen to study, the needs to repairmen are today not necessary. Yet the writers think that there are deformations that should be study more thorough, to derive the origin and take suitable measure. The writers think that the deformations that effect the constructions have most of their origin in some rebuilding and lost knowledge of old building engineering.</p>

The purpose with this report is to illuminate the construction solutions and the deformations that could exist in medieval parish stone churches. But also to increase the writers understanding how activity forces effect the construction of the churches. With help from literature and a practical study, containing three churches the writers have collected the material that the conclusions and discussions are built upon in this report. The construction of the churches consists of three parts, the wall, the roof and the vault. The construction solutions are similar in the churches disregard of the roof, where the roof trusses are different. The roof trusses are yet typical for the roman style. The deformations that have been found can in most cases be could usual occurring in these old churches the writers chosen to study, the needs to repairmen are today not necessary. Yet the writers think that there are deformations that should be study more thorough, to derive the origin and take suitable measure. The writers think that the deformations that effect the constructions have most of their origin in some rebuilding and lost knowledge of old building engineering.