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Methodology for the Performance Evaluation of Ceiling Recessions for Vertical Floor Opening ProtectionGrant, Steven January 2013 (has links)
Current Canadian Building Codes mandate prescribed design requirements for the protection of vertical floor openings by means of draft stops and closely spaced sprinklers. In the event that a design cannot meet the requirements, they also allow for the use of an alternative solution as long as the alternative solution can be proven to provide at least an equivalent level of performance as that prescribed in the Code. A commonly suggested alternative to the use of draft stops includes the construction of a recession at the perimeter of the floor opening; however, the performance of this design relative to that of an equivalent draft stop design has not been thoroughly evaluated.
In this research, the available methods for the evaluation of ceiling recession designs are reviewed in order to identify appropriate tools with which to conduct such an analysis. While both analytical analysis and experimental testing could be used, experimental testing of the design is not considered here as this option would not commonly be pursued by design teams due to restrictions on both project budget and design timelines. From the available analytical tools, the fire modeling software Fire Dynamics Simulator (FDS) is selected for evaluation of the ceiling recession design due primarily to the ability of FDS to address complex geometries with appropriate spatial resolution to investigate details of flow and thermal profiles at the ceiling level in a larger compartment.
Previous FDS studies are reviewed and an independent validation study is conducted in order to develop an analysis methodology which is appropriate for the evaluation of ceiling recession designs. A case study evaluation is conducted consisting of two dimensionally distinct ceiling recession configurations in the same compartment and two separate source fire heat release rates (HRR). Results are analyzed to evaluate the selected analysis methodology with respect to the characteristics of the simulated flow, and thermal detector response. Results show that the presence of an obstruction to the ceiling jet flow significantly improves thermal detector response where the source fire HRR is low. At higher source fire HRRs, the difference in activation time is found to be minimal amongst configurations of ceiling recession considered in the study.
Predictions of thermal detector response time for a selected ceiling recession design are compared to predictions made for code-prescribed draft stop configuration as would be necessary for an alternative solution evaluation. Results indicate that ceiling recession designs provide a reduced level of performance at both low and high source fire HRRs when the thermal detector is placed at the recession ceiling level. In contrast, when the thermal detectors are located at distances greater than 80 mm below the upper ceiling, a design which is permitted by the Code, the performance of the ceiling recession appears better than that of the prescribed draft stop design. Results from the model for detectors placed at distances from the ceiling exceeding 40 mm, however, require further confirmation through experimental testing or additional modeling.
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Methodology for the Performance Evaluation of Ceiling Recessions for Vertical Floor Opening ProtectionGrant, Steven January 2013 (has links)
Current Canadian Building Codes mandate prescribed design requirements for the protection of vertical floor openings by means of draft stops and closely spaced sprinklers. In the event that a design cannot meet the requirements, they also allow for the use of an alternative solution as long as the alternative solution can be proven to provide at least an equivalent level of performance as that prescribed in the Code. A commonly suggested alternative to the use of draft stops includes the construction of a recession at the perimeter of the floor opening; however, the performance of this design relative to that of an equivalent draft stop design has not been thoroughly evaluated.
In this research, the available methods for the evaluation of ceiling recession designs are reviewed in order to identify appropriate tools with which to conduct such an analysis. While both analytical analysis and experimental testing could be used, experimental testing of the design is not considered here as this option would not commonly be pursued by design teams due to restrictions on both project budget and design timelines. From the available analytical tools, the fire modeling software Fire Dynamics Simulator (FDS) is selected for evaluation of the ceiling recession design due primarily to the ability of FDS to address complex geometries with appropriate spatial resolution to investigate details of flow and thermal profiles at the ceiling level in a larger compartment.
Previous FDS studies are reviewed and an independent validation study is conducted in order to develop an analysis methodology which is appropriate for the evaluation of ceiling recession designs. A case study evaluation is conducted consisting of two dimensionally distinct ceiling recession configurations in the same compartment and two separate source fire heat release rates (HRR). Results are analyzed to evaluate the selected analysis methodology with respect to the characteristics of the simulated flow, and thermal detector response. Results show that the presence of an obstruction to the ceiling jet flow significantly improves thermal detector response where the source fire HRR is low. At higher source fire HRRs, the difference in activation time is found to be minimal amongst configurations of ceiling recession considered in the study.
Predictions of thermal detector response time for a selected ceiling recession design are compared to predictions made for code-prescribed draft stop configuration as would be necessary for an alternative solution evaluation. Results indicate that ceiling recession designs provide a reduced level of performance at both low and high source fire HRRs when the thermal detector is placed at the recession ceiling level. In contrast, when the thermal detectors are located at distances greater than 80 mm below the upper ceiling, a design which is permitted by the Code, the performance of the ceiling recession appears better than that of the prescribed draft stop design. Results from the model for detectors placed at distances from the ceiling exceeding 40 mm, however, require further confirmation through experimental testing or additional modeling.
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Projektering av en parkourbyggnad med förstärkning vid öppning i betongbjälklag / Designing of a building intended for parkour with a strengthened floor openingMickus, Deividas, Grujcic, Stefan January 2021 (has links)
Parkour är i grunden en konstform som kan utövas i olika miljöer oavsett om det är på enparkouranläggning eller på offentliga platser. Att utföra parkour är konsten att hitta och använda föremålsom hinder eller hjälpmedel för träning och för att utveckla rörelser. Aktiviteten går ut på ta sig frånpunkt A till punkt B på det snabbaste, smidigaste och effektivaste sättet. Bortsett från att parkour idaganses som en laglig idrottslig aktivitet anses den fortfarande som en typ av vandalism. Vad kan det beropå? Det beror främst på att en del parkourister väljer att utföra parkour på offentliga platser istället förspecifikt anpassade platser. Vad är anledningen att välja offentliga platser? Problemet att utföra parkour på specifikt anpassade platser är att de antingen inte är anpassade till enstörre målgrupp eller så är de ensidiga och saknar variation. Med det sagt begränsas aktiviteten till attendast enstaka förmågor kan testas. Projektering av en tvåplans parkourbyggnad i betong med öppningi bjälklaget är ytterligare ett sätt att testa en förmåga inom aktiviteten. Att utföra en sådan byggnad medrätt redskap, utformning och konstruktionslösningar krävde därför vägledning från en arkitekt och enkonstruktör. I rapporten redovisas olika typer av stomplan och studier bakom förstärkningsåtgärder vid öppning ibjälklag, för att besvara frågan: hur kan en öppning förstärkas om den saknar stöd i närheten? Val avstomplan och förstärkningsmetod har tagit hänsyn till dimensionering för böjande moment, men ävenatt projektet handlar om nyproduktion och estetiska aspekter som examensarbetet grundar sig på. Äventekniska och ekonomiska synpunkter är avgörande faktorer för valet. Tre stomplaner analyserades, men endast en stomplan valdes ut för vidare undersökning. Underarbetsgången behandlas olika förstärkningsmetoder som förstärkning med krage i form av armering ochförstärkning för fri kant. Förutom studie av förstärkningsmetoder dimensionerades betongplattan i olikatjocklekar med hänsyn till armeringsbehov. Rapporten grundades på ett finita elementprogram, FEM-Design 3D Structure, som användes förframtagning av moment och tvärkraft för olika modeller. För att underlätta arbetet gjordes ett flertalförenklingar som raka väggar vid hörn, hålet betraktas som rektangulärt, hinder/väggar på plattantolkades som laster m.m. Målet med förenklingar var att minska felmarginal som uppkommer i finitaelementmodell som sedan påverkar resultatet. Den slutsats som kan dras från resultat i FEM-Design, var att öppningen sänkte moment i plattan. Detberodde på att med en projekterad öppning kunde plattan delas upp i två mindre spännvidder. Vidareeftersträvades en förstärkningsåtgärd som inriktas till att förstyva plattan vid de kritiska områden ochsamtidigt uppfylla kraven som examensarbetet grundar sig på. Resultatet visade att det går åt mindrearmering för att öka momentkapacitet än för att minska på dimensionerande moment. Det betyder attdet blir mer ekonomiskt att åstadkomma en högre bärförmåga genom att höja momentkapaciteten än attminska dimensionerande moment med olika förstärkningsmetoder. Det som uppvisade bäst resultat var“stomplan 2” och användning av finita elementstorlek 0,15 m. Med analys av armering m.h.t. plattansolika tjocklekar kunde tjockleken 325 mm säkerställas och valet av 300 mm med förstärkning för frikant kunde visas som det bästa alternativet av de undersökta plattorna. / In general parkour is a form of art that can be performed in many different locations such as parkourparks or public places. The art of parkour is to find and use different objects as obstacles or as asupplement for training and development of different moves. Despite the fact that parkour is a legalactivity, it is still considered to be a type of vandalism. What is the reason for that? It is due to the factthat practitioners of parkour prefer to exercise in public places rather than limiting themselves inspecifically designed ones. Why do practitioners opt for exercising in public places? Firstly, the problem with those places is that they are not adapted for adults or they are ill-equipped andlack variation. Therefore, an activity gets limited because only a few abilities can be worked on.Designing a two-story concrete building intended for parkour with a floor opening is another way totest ability to parkour. In order to design that kind of building with the right appliance, shape andconstructive solutions, assistance from an architect and a constructor is required. This report shows different types of frameworks and studies behind strengthening solutions for a flooropening to find an answer for the following question: how can a floor opening be strengthened withouthaving the support for it in close proximity? Decisions of the framework and strengthening method areprimarily considered by bending moment, but also new productions and aesthetics of the building, whatthis dissertation is based on. The technical and economical aspects are also important for this decision. Three frameworks are analyzed, however only one of them will be chosen for further analysis. Theworking process shows various strengthening methods, for example strengthening by reinforcing theshape of the collar and strengthening the free edges. In addition to the study of strengthening methodsfor the floor opening, the concrete slab is analyzed in different thicknesses by considering the need ofthe reinforcements. The design is based on a finite element software FEM-Design 3D Structure that was used for calculationof moment and shear forces. Some simplifications were made to lighten the work. For example, straightwalls in the corners, floor opening was considered as a square, obstacles/walls on the slab wereinterpreted as a load, and many more. The aim of the simplifications is to reduce the room for errors inthe finite element model which has a potential to affect the results later on. The conclusion on the outcome of the models in FEM-design was that the opening reduces moment inthe slab. As a result of a projected opening, the slab was separated into two smaller spans. It furtherrequired a strengthening method to increase stiffness in the critical area and at the same time archivethe criterium for this dissertation. The results have shown that it requires less reinforcement byincreasing moment of resistance than reducing dimensioning moment on slab. That means that it ismore economical to increase the moment of resistance than to increase stiffness around opening withdifferent strengthening methods. Framework No.2 and usage of mesh size 0,15 m have shown the bestresults in this report. Analysis of reinforcement based on slab thickness gave a result of 325 mm whichled to a choice of slab 300 mm with reinforcement for free edges as the best alternative.
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