Quick Start Guide Prestressd Slabs - SOFiSTiK
ExampleQuick Start GuidePrestressd Slabs SOFiSTiK AG 2008
Example1ScopeSlab prestressing provides an economical way to decrease the amount of requiredreinforcement (ULS) while allowing for larger spans with slender slabs and betterstructural performance regarding crack and deflection control. For similar economicalgraphical input and FEA analysis, SOFiSTiK software offers special features withinthe Structural Desktop SSD and SOFiPLUS. In the following quick start guide thedifferent tasks and features will be explained briefly.Required versions: SSD 10.64-23 or higher for analysis / SOFiPLUS(-X)16.4/17.1-16 or higher for the graphical input.page 1Prestressed Slab
Example2System 2D Prestressed Slab and SSD Tasks for SlabPrestressWhen starting a new project, the System Information dialogue offers a new systemtype: 2D Prestressed Slab. This system type allows for plane slab systems includingmembrane effects and varying slab thicknesses with eccentric elements.For 3D structures and inplane restraints use the 2D Prestressd Slabsystem typeFigure 1: System Information dialogue for example projectAfter confirming the project setting, the SSD Task tree offers two special tasks.page 2Prestressed Slab
ExampleFigure 2: Task Tree for 2D Prestressed Slab SystemTask Prestressing SystemThe Task Prestressing System provides the possibility to select various predefinedprestressing systems which are provided by the software. A preselection isperformed according to the defined design code of the project.The textfile tendon.tab in the sofistik.23 folder contains the PT systemslibraryIndividual prestressing systems can be defined by the user generating thefile tendon usr.tabFigure 3: Task Prestressing System with example system selectedpage 3Prestressed Slab
ExampleExample System: SUSPA/DSI Monostrands 150 mm² acc. ETA-03/0036:Company: SUSPASystem:ETA Monolitzenspannverfahren ohne Verbund 150mm²Tendon:SUSPA 6-4 Y 1770 (Pack of 4 Monostrands)Check of the prestressing force:P0, max: with ft0.1k 1520 N/mm² 0.9*1520 N/mm² * 600 mm² 820 kNThe corresponding prestressing steel Y1770 (EN1992) can be generated in advanceusing the Task: Materials or directly in the Prestressing System Task:Figure 4: Material Strength PropertiesTask: Analysis of Slab PrestressThe Task Analysis of Slab Prestress computes the resulting forces for existing slabtendons, per default the loadcase number 700 and the action P is assigned to theresults.page 4Prestressed Slab
ExampleFigure 5: Task Analysis of Slab Prestress3Graphical Input of Tendons with SOFiPLUS(-X)The tendons layout can be defined easily within the graphical pre-processorSOFiPLUS(-X), the tendons are generated in ground view, computation of thecomplete tendon layout including friction loss calculation is performed during the‘Export’ (Meshing) of the system.Only important boundary conditions, as support lines, stop lines, distance of tendonsto the concrete faces and e.g. the transition lengths of the free tendon layout (FreieSpanngliedlage 1) have to be specified by the user.Figure 6: Free Tendon Layout (Freie Spanngliedlage) [1]SOFiPLUS Toolbox: Prestressing1Maier, K.; Wicke, M.; Die freie Spanngliedlage. Beton- und Stahlbetonbau 95, 2000, Heft 2 Pp.: 62page 5Prestressed Slab
ExampleThe input of tendons and their layout is done in SOFiPLUS using the ToolboxPrestressing. Three icons for the input of three elements: Input of Tendons, Input ofSupport Lines and Input of so called Stop Lines are available, their input options andthe modification of existing elements is explained below.Task: Generates new Tendons in ground viewOptions:Input of Tendon AutoCAD lines and polylines without kinks can be directlytransferred into tendonsPoints picked generate straight tendons parallel to the globalx- or y-AxisTendons along a side of the structure are best generatedusing the ‘distribute along line’ optionSkew layouts are possible using user coordinate systems(UCS)Modification of tendons: The tendon dialogue opens with adouble-click on one or more selected tendon elementsTask: Generates support lines which define the height of tendonelements crossing the lineInput ofSupport LineOptions: Direct input of support linesCurved object can be transferred into support linesModification of support lines: The properties (i.e. distance oftendon from concrete face along line) of a support line are editedusing the AutoCAD properties dialogueTask: Generates stop lines out of AutoCAD objects which causethe intersecting tendons to endInput of Stop Options:Line Selection of Lines etc. to become a stop lineModification of stop lines: The stop line objects are copied in aseparate layer, modification is possible in the same way as for allAutoCAD objectspage 6Prestressed Slab
ExampleSOFiPLUS Tendon DialogueDouble clicking on one or more selected tendon elements opens the SOFiPLUSDialog Tendon, here the necessary input for tendon parameters is possible.The arrow on one end of the tendon indicates the ‘left’ endFigure 7: Tendon dialogue§§§§§§Prestress direction: Definition of active and passive anchor sideKind of prestressingTendon geometry: Free tendon geometry or cubic spline geometry can beselectedStraight part in top position: Length of the straight part over highpoints(colums etc.), only for free tendon layoutTransition: Transition length of the free tendon layout, only for free tendonlayoutDistances of axis to upper and lower concrete edgepage 7Prestressed Slab
ExampleFigure 8: Formula for transition lenght [1]Figure 9: The Points tab allows for geometry modification of single tendonsFigure 10: Input of tendon distance for a support linepage 8Prestressed Slab
ExampleFigure 11: Stop Line (red line)4Analysis and Post ProcessingAfter the definition of the tendons with SOFiPLUS, the SSD is used to control thefurther analysis and the post processing, the Task Linear Analysis is used tocalculate all loadcases except prestress, here the aforementioned Task Analysis ofSlab Prestress is employed. The reports of all calculation steps are managed usingthe URSULA button of the SSD, further reference on the SSD can be found via Menu‘Help’ Quick Reference.The complete tendons friction calculation results are available as projectname tnd.plb via the Menu ‘Open’ of URSULAFigure 12: Report of tendon calculationpage 9Prestressed Slab
ExampleFigure 13: Tendon axis of free tendon layoutFigure 14: Tendon stresses (dashed line: Pm0,max 0.945*P0,max 0.85*1520 N/mm²); Maximumtendon force indicated red.For simplified consideration of creep, shrinkage and relaxation losses, the TaskDefine Superpositioning is used to assign a factor (e.g. 0.88 for 12% CSR losses) topage 10Prestressed Slab
Examplethe prestressing loadcase in the automatically generated loadcase combinations (e.g.EC2-2004, ULS and SLS combination).Figure 15: Factor for simple CSR considerationThe design in ULS and SLS of the prestressed slab is carried our using the standarddesign Tasks: Design ULS/SLS – area elements.Remark on punching design for prestressed slabs:Using BEMESS 11.90-23 the inclination and force of tendons crossing the punchingarea is automatically detected and considered in the punching design and checks,the mean compressive stress sigma-cd is considered for EC2-2004 and DIN 1045-1,selecting extensive text output for punching the prestress reduction force Vpd andthe individual contributions can be checked.page 11Prestressed Slab
ExampleFigure 16: Extensive BEMESS output for punching design with tendonspage 12Prestressed Slab
Example5Example SystemExample Slab System according EC2-2004Lx 5/8/6 mandLy 6/6mColumns:diameter 40 cm/ heigth 3.00 m/ C 30/37Slab thickness:t 26 cmConcrete:C 30/37Rsteel:S 500Prestressing steel:S Y1770Concrete cover:3 cmPermanent loads:automatic selfweight 1.50 kN/m²Live loading:3.25 kN/m²page 13Prestressed Slab
SOFiSTiK AG 2008 Quick Start Guide Prestressd Slabs . Example page 1 Prestressed Slab 1 Scope Slab prestressing provides an economical way to decrease the amount of required reinforcement (ULS) while allowing for larger spans with slender slabs and better
tion of these slabs. Topping slabs have many of the same issues that slabs-on-ground and structural concrete slabs have. Concrete practices related to crack control, shrinkage and temperature control, concrete jointing, concrete mixture design, and concrete curing for elevated slabs and slabs-on-grou
usually one and two-way spanning slabs Punching shear –e.g. flat slabs and pad foundations Shear There are three approaches to designing for shear: When shear reinforcement is notrequired e.g. usually slabs When shear reinforcement isrequired e.g. Beams, se
chapter 2 structural behavior of two-way slabs 17 2.1 types of two way slabs 19 2.2 behavior of two-way slabs 22 2.3 analysis methods for two way slabs 25 2.4 review of elastic plate bending theory 32 2.3 finite element analysis for two-way slabs 38 chapter 3 theoretical analysis of two-
4.1 Quick Start Tutorial When Collect is opened for the first time, the Quick Start tutorial is displayed. Quick Start is a series of five screens that provide a summary review of the main capabilities of the app. Tap the Forward icon to move through the Quick Start screens. Tap Start to open the app after finishing with the Quick Start screens .
Segmental Concrete Paving Slabs in the United States. In Canada pavers and slabs are manufactured in accordance with CSA A231.1/A231.2 Precast Concrete Paving Slabs/ Precast Concrete Pavers. Interlocking Concrete Pavement (ICP) requires periodic inspection and maintenance to ensure long-term performance throughout the pavement life.
0.8 manhours per sq.m for flat slabs 1.5 manhours per sq.m for beam & slabs (beams using conventional system) 1.0 manhours per sq.m for beam & slabs (beams using beam forming support system) Salient Features l Foldable tripods eliminate the need for bracings l Flexible spacing and arrangement options l Simple shuttering & de-shuttering results
width and length of a rectangular slab are accounted for in an approximate way in most practical design methods by designing for a reduced moment in the outer quarters of the slab span in each direction. It should be noted that only slabs with side ratios less than about 2 needs to be treated as two-way slabs.
ANSI/AAMI HE74 (2001-2010) “Human factors design process for medical devices” ANSI/AAMI HE75 (2009- ) “Human factors engineering - Design of medical devices” (a Tutorial to HE-74) 37 . US & FDA FDA Human Factors Draft Guidance Document: Agency Expectations for Human Factors Data in Premarket Submissions Applying Human Factors and Usability Engineering to Optimize .
