EPU (ESA-Punching) MANUAL

Transcription

1 EPU (ESA-Punching) MANUAL SCIA Scientific Application Group

2 Release : 3.50 Module : EPU.01 Manual : EPU Revision : June 2002 SCIA Group n.v. Scientific Application Group Industrieweg 1007 B-3540 Herk-de-Stad (België) Tel.(+32) (0)13/ Fax.(+32) (0)13/ scia@scia.be SCIA W+B Software b.v. Postbus 330 NL-6860 AH Oosterbeek (Nederland) Tel.(+31) Fax.(+31) scia@scia.nl SCIA sarl Parc Club des Prés Rue Papin, 29 - F Villeneuve d'asq (France) Tel.(+33) (0) Fax.(+33) (0) scia@nc.net.tm.fr SCIA Software Gbr Emil-Figge-Str. 76 Gebäude I Tel.(+49) 231/ Fax.(+49) 231/ scia@scia.de

3 ABOUT THIS MANUAL The following conventional text formats and symbols are used throughout this manual : Convention bold [between brackets] Italic text 1. Step 1 2. Step 2 Menu > Submenu Meaning Indicates texts used in the program (menus, texts in dialog windows, buttons, etc.). E.g. Enter the length of the beam in the Length field. Indicates a button. E.g. Click on [OK] to confirm. Indicates a procedure to follow to execute this operation. E.g. To change the properties of... Indicates the different steps in a procedure. Each step describes one action. E.g. 1. Enter the value in the Coefficient field. 2. Click on [OK] to confirm. Indicates items and subitems from the main menu (on top of the screen) or from the menu tree (left side of the screen). E.g.... choose Setup > Options from the main menu. Information in this document is subject to change without notice. No part of this document may be reproduced, stored in a retrieval system or transmitted, in any form or by any means, electronic or mechanical, for any purpose, without the express written permission of the publisher. SCIA Software is not responsible for direct or indirect damage as a result of imperfections in the documentation and/or software. Copyright 2002 SCIA Group. All rights reserved.

4 TABLE OF CONTENTS INTRODUCTION... 3 MAIN INTERFACE... 4 PUNCHING CALCULATION... 6 THE PUNCHING MENU TUTORIAL EXAMPLE THEORETICAL BACKGROUND EC NEN BS... 37

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6 INTRODUCTION Welcome to the Single Punching Module (EPU) manual. This program is a stand alone part of ESA-Prima Win (EPW), a designing and analysing program under Windows 95/Windows 98/Windows NT/Windows2000/WindowsXP with a wide range of applications: from control of simple frames to advanced design of complex projects in steel, concrete, timber,... This manual is specifically made for the stand-alone module for the punching calculation and the design of punching reinforcement. Experienced users of ESA-Prima Win immediately recognise the look of the EPU program. As a fact EPU is subtract of the EPW program and uses the same functions as EPW. EPU however is meant for 'basic' punching calculations only, EPW is capable of making punching calculations using the dimensions, properties and results as defined or calculated in EPW. Since EPU uses the same functions as EPW for some parts of the program this manual will refer to the EPW manual. Especially the part concerning the 'general' interface, like printing, units set-up, workspace, etc. will not be discussed in this manual. For these items the user should refer to the "ESA-Prima Win Reference manual" and the "ESA- Prima Win Reinforced concrete manual". Most functionality in the modules depends on national codes. The following national codes are available within EPU : Eurocode 2 DIN DIN /88 SIA 162 BS 8110 NEN 6720 ONORM B 4700 (beams and columns) CSN STN BAEL 91 In the first part the interface of the program is described. In the second part the punching calculation is described. In the third part the punching menu is described. In the fourth part an example calculation is given. As an appendix a theoretical background is given. SCIA 3

7 MAIN INTERFACE After the initiation of the program, the user must press the [ ] button to start a new punching calculation. Then the user is asked to set the values for the national codes, units and concrete class. Additionally the user can set project specific text, etc., see figure: SCIA 4

8 After pressing the [OK] button, the following screen is depicted: The menu tree consists of the following branches 'Punching' and 'Document'. In the document all calculations that the user send to the document have be stored, see EPW manual. In the 'Punching' branch the punching calculation and design of punching reinforcement is performed. Double clicking on the 'Punching' branch starts the punching calculation. SCIA 5

9 PUNCHING CALCULATION The punching component consists of the following tab sheets. - Geometry of punching - Main reinforcement - Loads - Design of reinforcement - Doc Setup - Doc Preview They are separately threated in the following paragraphs. Geometry of punching The data of this tab sheet are mainly used to determine the critical perimeter. SCIA 6

10 Description Here the user can enter an individual description per calculation. The Column type group Column data The dimensions of the column can be defined in these fields. The axes in the picture are the local axes of the column. Hole data Check the 'Hole' box, if one want to define a hole. One can define circular as well as rectangular holes. In this group, the dimensions of the hole have to be defined. The Column Position group Column position The following column positions are available - Parallel to the x-side - Parallel to the y-side - Corner column - Central column The axes in the picture are the axes of the plate - Parallel to the x-side Column distance y Distance in the y-direction between the edge of the slab and the nearest side of the column. Angle of edge with x-axis - Parallel to the y-side Analogue to parallel to the x-side Angle of the edge in respect to the local axis of the column. SCIA 7

11 - Corner column Column distance y Distance in the y-direction between the corner and the nearest side of the column. Column distance x Distance in the x-direction between the corner and the nearest side of the column. Angle of vertical edge Angle of horizontal edge - Central column No position definition is needed Angle of the edge of the slab with the x-axis Angle of the edge of the slab with the y-axis Hole position If one checked 'Hole' in the Column type group, the following positions have to be defined. Hole distance y Hole distance x Distance in the y-direction between the hole and the x-axis through the centre of the column. Distance in the x-direction between the hole and the y-axis through the centre of the column. SCIA 8

12 The Section group Plate data Thickness of the plate Thickness of the plate at the critical perimeter. Column head data group Column head prismatic pyramidal cylindrical conical Column head measurements Check this box to define a column head. For rectangular columns one can only define rectangular heads. For circular columns one can define both circular as well as rectangular heads. Select the type of the column head. Prismatic and Pyramidal are for rectangular columns, cylindrical and conical are for circular columns Depending on the column head type the depth and width of the column head can be defined using the appropriate fields. The Material group [Concrete] Click this button to change the material quality of the slab. The Actual Material dialog box will appear. SCIA 9

13 Loads SCIA 10

14 For each loadcase/combination, selected in the Concrete > plates, walls, shells > punching menu, the loads / internal forces are shown. Qd Vd Mxd Myd Distributed load (2D) on the slab of the appropriate loadcase/combination Input > Loads > Distributed loads 2D. It is used to correct Vd punching force V Sd_punch (see theoretical background). Concentrated load, causing the punching force. For a support, this is the reaction force. For a column, it is its normal force that works on the slab. Bending moment per unit length in the x-direction in the slab for the appropriate loadcase/combination. Results > 2D forces - 'in nodes' This moment is only used the check the minimum design bending moments. Bending moment per unit length in the y-direction in the slab for the appropriate loadcase/combination. Results > 2D forces - 'in nodes' This moment is only used the check the minimum design bending moments. For the convention of the signs, see the picture in the tab sheet. SCIA 11

15 Main reinforcement This tab sheet determines the longitudinal reinforcement amount in the plate near the node that is considered. Profile group, Angle group and Material group The same groups as in the levels of reinforcement dialog box (Concrete > plates, walls, shells > input - [Reinforcement] ). See the appropriate part in the concrete manual for more information about these fields. SCIA 12

16 Distance group In the fields in this group the distances between the longitudinal bars in a layer are shown. Area group In this group, the areas per unit length for the corresponding layer are shown. SCIA 13

17 Design of reinforcement SCIA 14

18 Loads (Case/Combi) group In the list box, one can select one of the cases/combinations that were defined in Tab sheet Loads. For this loadcase/combination, the results of the punching control are shown. Critical section group For each code the important values are shown. See the theoretical background for more explanation on how the following values are calculated. [Calculation] Click on this button to perform a calculation when values are manually changed. SCIA 15

19 Doc Setup In this tab sheet, one can define the document setup of the preview and numerical output to document or printer. SCIA 16

20 Doc Preview In this tab sheet, a preview is given of the results of the punching control of the appropriate node. SCIA 17

21 THE PUNCHING MENU After pressing [OK] the user enters the following dialogue. In this dialogue the user manages the number of punching calculations in this project by deleting, editing, printing, etc. SCIA 18

22 Calculation group In this group the user can copy and edit the punching calculations as shown in the list box. [New punching] [Edit punching] This button starts a new punching calculation. This button edits an existing punching calculation. Select the appropriate calculation in the list box first. Delete group In this group the user can delete one or all punching calculations. [Delete punching] [Delete all] This button deletes an existing punching calculation. Select the appropriate calculation in the list box first. This buttons deletes all existing punching calculations. Numerical output group [Change of setup] [Preview All] This option is the same as those in tab sheet 'Doc setup' of the punching component. Click this button to perform a punching calculation for all selected calculations and print the results to a preview, document, ASCII or RTF. [Close] [Code Setup] This button will return to the menu tree of EPU. This button will open the setup of specific code values, see figure. SCIA 19

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24 [Default settings] This button will open the dialogue with all the default settings. If the user saves his workspace in the menu bar > file > save workspace, every time a new calculation is done, these settings will be used. The 'retrieve workspace' function will retrieve the default EPU values. SCIA 21

25 TUTORIAL Example Start the program. Select the flag of the NEN Select concrete class B35. Then the dialogue should look similar to the following figure: If necessary enter a name, author and specification for the project. SCIA 22

26 Press the [OK] button and double click on the 'Punching' branch in the EPU menu tree. Change the properties of the tabsheet 'geometry of punching' according the following figure: SCIA 23

27 Change the values of the tabsheet 'loads' according the following figure: Note: One can add, delete or clear a row by clicking with the right mouse button on '1', see figure: SCIA 24

28 Change the values of the tabsheet 'Main reinforcement' according the following figure: SCIA 25

29 Go to tab sheet 'calculation' and note the results of the punching calculation: Set the correct steel quality by clicking on button [steel] and set it to 'FeB500'. The calculated punching reinforcement is 437 [mm 2 /m 1 ]. Since the perimeter is [m] the total punching reinforcement is = 853 [mm 2 ]. By clicking on the tab sheets 'section x' and 'section y' one can review the sections, see figure: SCIA 26

30 Section x Go to the tab sheet 'Doc Setup' and select 'detailed'. Press on button [unselect all] and tick the following options: 'results of calculation' and 'ground plan'. Go to 'Doc Preview' tabsheet and note the following output: SCIA 27

31 Press the button [OK] and press the button [preview all] and select the option 'preview + print'. The output should look similar to the following figure: SCIA 28

32 THEORETICAL BACKGROUND In this paragraph, the different aspects of the control of punching shear resistance in EPU are described. EC Shape of the loaded area A check is performed whether the loaded area is within the limits of EC (1).a. The parameters of this check can be modified in the setup > concrete menu, tab sheet 'punching settings'. Determination of the critical perimeter The critical perimeter depends on the loaded area and the plate thickness as described in EC (1). 1.5 d 1.5 d Near openings or edges, this critical perimeter has to be decreased. The rules as described in EC (2) and (3) are applied. SCIA 29

33 1.5 d 1.5 d Checking punching shear - first critical section The following conditions have to be met Slabs without punching shear reinforcement v Sd < v Rd1 Slabs with punching shear reinforcement v Sd < v Rd2 v Sd < v Rd3 Min. plate thickness (EC (5)) Setup > Concrete - Tab sheet 'Punching settings' Min. shear reinforcement amount (EC (4)) Setup > Concrete - Tab sheet 'Punching settings' SCIA 30

34 Calculation of v Sd v Sd = V Sd_punch u.β V Sd_punch Beta u See reinforced concrete manual, Punching, the punching component, Design of reinforcement, Loads (case/combi) group: V d of the appropriate loadcase / combination q d of the appropriate loadcase / combination Setup > concrete - tab sheet 'Punching settings' The calculated critical perimeter See reinforced concrete manual, Punching, the punching component, Geometry of punching. Example for calculation V Sd_punch q d = -10 kn/m2 V d = 90 kn V Sd_punch = * A crit So V d is decreased by a loading q d within the critical area. The contact stresses within the surface of the cone (as in EC (4)) are not taken into account. SCIA 31

35 Calculation of v Rd1 v Rd1 = τ Rd.k.( ρ l ).d τ Rd Determined by the concrete quality. k d 1.0 ρ l d See reinforced concrete manual, Punching, the punching component, Main Reinforcement See reinforced concrete manual, Punching, the punching component, Geometry of punching (Thickness plate) and Main reinforcement (Covers, diameters) Calculation of v Rd2 v Rd2 = ' coeff'.v Rd1 'coeff' Setup > concrete - tab sheet 'Punching settings' 'Coefficient for vrd2'; default 1.6 Calculation of v Rd3 v Rd3 = v Rd1 + A sw f yd sinα u A sw f yd α u (Calculated) punching shear reinforcement amount See reinforced concrete manual, Punching, the punching component, Main reinforcement (steel quality) and Setup > concrete (Safety factor) See reinforced concrete manual, Punching, the punching component, Design of reinforcement The calculated critical perimeter SCIA 32

36 Checking punching shear - More critical sections As long as the critical section considered needs punching shear reinforcement, an analogue punching check has to be performed for the next critical section. Minimum design moments 'To ensure that the punching shear resistance can develop, the slab should be designed for minimum bending moments per unit width' (EC (1)). The following conditions should be met m Rdx max ( limit m Sdx, m Sdx orig. ) m Rdy max ( limit m Sdy, m Sdy orig. ) m Rdx Resistant bending moments per unit length in the x-direction. See reinforced concrete manual, Punching, the punching component, Main reinforcement (reinforcement) limit m Sdx Limit design bending moment per unit length in the x- direction = 'η. V Sd ' m Sdx orig. η Setup > Concrete - Punching settings ('Coefficients') Design bending moments per unit length in the x-direction See reinforced concrete manual, Punching, the punching component, Design of reinforcement, Loads (appropriate loadcase / combination) SCIA 33

37 NEN The shear punching calculation in EPU is performed according to the NEN 6720 code. Only additional information and some remarks to the calculation routine are given in the next topics. Check criteria The first check perfomed during the shear punching calculation is concerning the a l /a b ratio of the loaded area. For rectangular loaded areas having a ratio a l > 3 a b a shear force calculation is done according NEN6720 art The absolute maximum value for τ 2 can be altered in the Setup for concrete dialogue, tab sheet Punching settings. Design value of the shearforce The used forces (V d, M x, M y ) to determine τ d, which are shown in the Loads tab sheet, can be checked in the Results > Member forces menu. For each periphery the design shear force is calculated. At first instance the perimeter is considered for a mid column. However, if the distance from the c.g. of the loaded area to the edge of the slab (ar) is smaller than a 0.25 times the perimeter or times the perimeter then it will be considered as a edge column, corner column respectively. Hence the following situation can occur: Possible perimeters in a punching check calculation The eccentricities e x and e y are determined parallel to to main axis of inertia of the periphery. For corner columns this implies that the moments found in linear analysis have to be rewritten. To determine the eccentricities as shown in the figure below, the linear analysis moments are rewritten as follows: SCIA 34

38 M dy = -M x cos α + M y sin α M dx = M x sin α + M y cos α α = π /4 (in normal circomstances) e x = M dx / N d e y = M dy / N d The values for the factors α x and α y, used in determination of the eccentricity factor, are calculated according the tables 30 to 34 including. Values which are not mentioned in the table are linear interpolated. Calculation of tau 1 The value of tau 1 is determined in two steps, i.e. in the first step tau1 is calculated with the equation as mentioned in art with a minimum of 0.8*fb. Although the minimum value for tau 1 (0.8*fb) can be altered in Setup for Concrete tab sheet Punching settings. In the second step tau 1 is multiplied with k1 and k2 if the geometry of the column requires this. Calculation of A sv As long as τ d > τ 1 τs and A sv will be calculated. The maximum number of peripheries that will be considerd is 10. Default the angle between the punching reinforcement and the suface of the slab is taken as 90. In the tab sheet Design of Reinforcement in the Punching dialogue this value can be altered. SCIA 35

39 Column heads acc. NEN In cases of column heads two situations are distinguished. In the first situation (a k h k ) the first section is taken at 0.5 d from the face of the column head. In the second situation also section within the column head should be checked. The picture below illustrates the location of such a section. It is 0.5 (d+h k ) beyond the diameter of the loaded area (a) at each side in both directions. Location of critical section in case of column head where ak hk SCIA 36

40 BS The shear punching calculation in EPU is almost exactly according BS8110 code. Therefore only additional information and some remarks are given in the next topics. Location of perimeter Depending on the choice made in Setup for concrete > tab sheet Punching settings the first critical section will be taken at 1.5d or 0.75d from the face of the column. Default the distance lp of the first perimeter is set at 1.5d. If the requirement υ c < υ <2υ c is still valid after this first check other perimeters are checked. They are taken at distances which are a multiple of 0.75d beyond the first perimeter. Calculation of V eff The BS mentiones two ways to calculate V eff ; the first one uses the transmitted moment to determine V eff (equation 25 and 26) the second is a simplyfied method as it uses a mutiplication factor to determine V eff. Both methods are implemented in ESA-Prima Win. In the Setup of concrete, tab sheet Punching settings the appropriate method can be chosen. The used forces (V t, M t ) to determine V eff, which are shown in the Loads tab sheet, can be checked in the Results > Member forces menu. Maximum design shear capacity υ max The maximum design shear stress is restricted to the lesser of 0. 8 fcu and 5 N/mm 2 or is limited by the provisions for shear reinforcement (υ c < υ < 2υ c ). The minimum of all these values is used as maximum design shear capacity in ESA-Prima Win. If exceeded a message will be given. Design concrete shear stress υ c To calculate υ c the equations as mentioned in table 3.8 of BS8110 are used. For this only the reinforcement crossing the perimeter is effective. Therefore only the reinforcement crossing the perimeter is taken into account when detemining υ c. SCIA 37

41 Column heads acc. BS For column heads it is not exactly clear where the first critical section should be taken. However, comparing the punching check calculation to other norms (e.g. EC2 and NEN6720) a good approach can be made. The BS is rather clear about the effective dimensions of a column head (BS ). These dimensions are the basics for determine the first critical section. Mainly two different situations can be distinguished, i.e.: 1. l ho < l h max In these situations the first critical section is taken at 0.75/1.5 * d slab of the effective dimensions of the column head. So only sections in the slab are checked. Situation ii and iv of Figure 3.11 of BS8110 and their 1st critical section 2. l ho > l h max In these situations it can be interesting to check sections inside the column head also. Esa Prima Win checks sections inside the column head when the section at 0.75/1.5*(d head + d slab ) of the column falls inside the real column head dimensions. In such situation the section section is taken at 0.75/1.5*(d head + d slab ) *d slab of the column. SCIA 38

42 Situation i and iii of Figure 3.11 of BS8110 and their 1st, 2nd critical section If the section at 0.75/1.5*(d head + d slab ) of the column falls outside the column head, only the sections as mentioned in 1 are considered. SCIA 39