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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Study of glue-laminated timber connections with high fire resistance using expanded steel tubes

Ronstad, David, Ek, Niklas January 2018 (has links)
A key factor regarding fire safety of timber buildings is the performance of connections between the structural elements, since this determines the load-carrying capacity of the structure. Traditional timber connections do generally perform poorly in a fire compared to surrounding parts since the joints often consist of exposed metal parts and cavities which locally decreases the fire resistance. This weakness does often lead to the appliance of gypsum which removes the aesthetic appearance of timber. Through an innovative timber connection design, the hope is that the failings at elevated temperature are changed from the connection itself to surrounding parts thus increasing the fire resistance to the limits of the connected components. Two types of glue-laminated timber connections have been built and tested at RISE facilities in Borås with the purpose to determine if these could withstand fire exposure for 90 minutes under load. The connections are assembled by expanding hollow steel tubes that clinches the members together and at the same time makes the steel tube yield against the inside of the pre-drilled hole. Pre-stresses are created in the connection during this process that avoids an initial slip if the connection is loaded, which is one of the reasons that this type of connections is suitable in earthquake-prone areas. The joint design results in a significantly increased rotational stiffness, moment capacity and embedded energy of the joint in comparison with conventional timber connections. One of the connections is designed to withstand moment forces. The specimen is built as a beam to beam connection that is subjected to a four-point bending test at both ambient and elevated temperature. The connection withstood 39.5 kNm in ambient temperature and failed after 87 minutes and 6 seconds of fire exposure under load. However, failure in elevated temperature did not occur within the connection, and visual inspection after the test indicated that the steel tubes still were in excellent condition. The connection is therefore expected to have been able to withstand 90 minutes of fire exposure. The other connection is designed to withstand shear-forces and is built as a column to beam connection that is tested at both room temperature and elevated temperature. The connection endured a maximum shear-force of 181.4 kN in ambient temperature, approximately 30 kN higher than previously performed test with identical setup, and failed after 113 minutes of fire exposure under load. The failure in elevated temperature did however not occur inside the connection. The testing is limited to unprotected connections consisting of glue-laminated timber which are tested in accordance with ISO 834. / En nyckelfaktor för brandsäkerheten i träbyggnader är prestandan hos förbanden mellan konstruktionselementen eftersom dessa bestämmer konstruktionens lastbärande kapacitet. Traditionella träförband har i allmänhet dåligt brandmotstånd i förhållande till omgivande delar, detta eftersom förbanden ofta består av exponerade metalldelar och kaviteter som lokalt försvagar brandmotståndet. Dessa svagheter motverkas ofta genom att montera gips vilket negativt påverkar träets estetiska utseende. Genom en innovativ konstruktion av träförband är hoppet att den svaga punkten vid förhöjd temperatur flyttas från själva anslutningen till omgivande delar, vilket ökar konstruktionens brandmotstånd genom att brandmotståndet då begränsas av prestandan hos de anslutna komponenterna. Två typer av limträförband har byggts och testats vid RISE-anläggningen i Borås med syfte att bestämma om dessa under belastning skulle kunna stå emot brandexponering under 90 minuter. Förbanden monteras genom att expandera ihåliga stålrör som klämmer samman elementen och samtidigt deformeras mot insidan av det förborrade hålet. Förspänningar skapas i förbandet under denna process som förhindrar en primär förskjutning om förbandet är lastat, vilket är en av anledningarna till att denna typ av anslutningar är lämpliga i jordbävningsbenägna områden. Denna konstruktion resulterar i en betydligt ökad rotationsstyvhet, momentkapacitet och inbäddad energi i jämförelse med konventionella träförband. En av anslutningarna är konstruerad för att motstå momentkrafter. Provkroppen är byggd som en balk-balkanslutning som utsätts för ett fyrapunkts böjningstest vid både rumstemperatur och förhöjd temperatur. Anslutningen klarade 39.5 kNm vid rumstemperatur och fallerade efter 87 minuter och 6 sekunder av belastning i förhöjda temperaturer. Brottet i förhöjd temperatur inträffade emellertid inte i anslutningen och den visuella inspektionen som utfördes efter testet indikerade att stålrören fortfarande var i utmärkt skick. Anslutningen bedöms därför ha kunnat motstå 90 minuters brandexponering. Det andra förbandet är konstruerat för att motstå tvärkrafter och är byggt som en pelare-balkanslutning som testas vid både rumstemperatur och förhöjd temperatur. Anslutningen klarade en maximal skjuvkraft på 181.4 kN vid rumstemperatur, cirka 30 kN högre än tidigare utfört test med identisk uppställning, och fallerade efter 113 minuters belastning i förhöjd temperatur. Brottet i förhöjd temperatur inträffade emellertid inte i själva anslutningen. Testerna är begränsade till oskyddade förband bestående av limträ som under brandpåverkan testas enligt ISO 834.
2

Rozhledna v Beskydech / Lookout tower in Beskydy mountains

Prokop, Miroslav January 2020 (has links)
This master thesis deals with the design of load-bearing capacity of the observation tower in Besky-dy. The material used in main column is steel S355. The main column is a circular hollow construc-tion with diameter of 2,2 m. Inside the column is located a double spiral staircase. The upper part of observation tower simulates shape of treetop by rip column. It is made of glue laminated timber GL24h. The tower has four platforms of hexagon shape. The largest platform is 12,2m wide. The height of struction is 37,5 m. Internal forces have been calculated in software RFEM and based that the structural assessment has been made. The thesis is drawn up pursuant to the standards of ČSN EN.
3

Instabilitet i underspända takkonstruktioner av limträ : Identifikation och kontroll av stabilitetsstyrande parametrarför underspända limträkonstruktioner

Hansson, Pär Åke January 2022 (has links)
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>
4

Jezdecká hala ve Valašském Meziříčí / The Riding Hall in Valašské Meziříčí

Rantová, Katarína January 2018 (has links)
The subject matter of this diploma thesis is a design timber structure of riding hall. The hall is a one nave building. The dimensions of ground plans is 32,0m x 70,0m and the hall is 10,0 meters high. The load-bearing structure consists of arched ribs.This timber structure composed of glued laminated timber. The building is located in Valašské Meziříčí, climate loads are designed for the area. The calculation were made in accordance with the Czech technical norms ČSN EN. The structural design and analysis is performed by software SCIA Engineer 17.
5

Aquapark / Aquapark

Vincour, Jan January 2014 (has links)
Object of Diploma thesis is the structural design of a load bearing structure of the aquapark in the Brno area. The main structure is designed as lamella arch on the cylindrical surface with one curvature with 30 m span and 4.5 m camber. The structural material is glue-laminated timber with inner steel plate joints.
6

Multifunkční objekt ve Znojmě / Multifunctional building in Znojmo

Tapšáková, Ivana January 2014 (has links)
The subject of the master thesis is a design and static analysis of the load-bearing multi-storey steel structure with the timber entrance shelter of the multifunctional building in Znojmo city. There is a shopping centre situated on the ground floor, other floors are mostly used as offices. The ground plan of the steel structure has a shape of a regular 20-tagon with circumscribed circle diameter 30 m. The height is 35,5 m. The building has 6 storeys at all. The racking resistance is ensured by combination of frame-shear truss and rigid frame. In the front part of the building there is an airy cut-out space situated and it is running from the ground floor until the roof structure. The glue laminated timber shelter by the entrance of the building reaches a height of the first floor and its length is 10 m.
7

Vyhlídková věž v západních Jeseníkách / The Viewing Tower in Western Jeseníky

Nosková, Denisa January 2015 (has links)
The purpose of this thesis is to create design and static assessment of the viewing tower in western Jeseníky mountains. The Ground plan is formed by regular hexagon with outer diameter 0.8 meter. Glued laminated profiles, steel tubes and elements of solid wood were predominantly used for the construction of the building. The viewing tower has four viewing platforms and total high of the structure is 28.5 meters.
8

Rekreační jezdecké středisko / Recreational Riding Resort

Slavíková, Michaela January 2016 (has links)
This final thesis projects an areal of riding center with four objects. The first one is complex of stabels ,the second one is riding hall, , and the last two area family house and litte apartment for accomodation of employeers and visiters. For objects one and two is complete documentation, the other ones are processed as a studie. All the buildings are designed as a timber structure, the ridding hall is created by glue laminated timber girders.
9

Jezdecký areál / Riding area

Lauková, Alžbeta January 2016 (has links)
The aim of the project is a new construction of an equestrian center in the cadastral area Kuřim, South Moravian Region. It is designed for the public. The building has two aboveground floors. In the object there is stable, a riding hall with handy storages that are separate from the public. Another part is divided into facilities for riders, restaurant and accommodation. The second floor has a café, shop and offices. The hall is designed as a reinforced concrete frame, the other parts of the brick system Porotherm. The roof is pitched. The cladding is designed as a ventilated facade.
10

Konstrukce autosalonu v Jihlavě / The Showroom Structure in Jihlava

Stloukal, Radim January 2017 (has links)
The subject of this thesis is a structural design of a car showroom in municipality Jihlava. For this purpose two different concepts were developed. The main bearing system of the first consists of steel truss girder supported by single profile steel columns. The second idea, a structure with axial ground area 36,0 x 18,5-23,5 m , is made from glue laminated timber. The second mentioned concept was chosen for detailed calculation and documentation. The structure was modelled by 1D member while using Scia Engineer. Results obtained from the computer analysis were taken and main strutctural members were check by manual calculation.

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