Analysis and concrete Design of structure with STAAD.Pro V8i

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Analysis and concrete Design of structure with STAAD.Pro V8i

                                                        
Introduction to Staad.pro V8i
                   Stadd.Pro V8i is the most popular structural engineering software product for 3D model generation, analysis and multi-material design. It has an intuitive, user-friendly GUI, visualization tools, powerful analysis and design facilities and seamless integration to several other modeling and design software products. The software is fully compatible with all Windows operating systems but is optimized for Windows XP.
       For static or dynamic analysis of bridges, containment structures, embedded structures (tunnels and culverts), pipe racks, steel, concrete, aluminum or timber buildings, transmission towers, stadiums or any other simple or complex structure, Stadd.Pro has been the choice of design professionals around the world for their specific analysis needs. 
      Stadd.Pro is a general purpose program for performing the analysis and design of a wide variety of types of structures. The basic three activities which are to be carried out to achieve that goal - a) model generation b) the calculations to obtain the analytical results c) result verification - are all facilitated by tools contained in the program's graphical environment.
      The staad model is prepared to the scale in the working space of staad. The frame structure model is generated which consists of beams and columns and then the material with their cross-section properties are inputted to staad. The loads are then assigned and after that the structure is analyzed with the help of the staad program.
The whole process of the analysis and design are given below.
1.     Inputting the job Information: Firstly the information of the project is written after opening the staad. As the name of the project/job, Client’s name and the date when project started and the name of the Engineer as well and much more information is inputted.

2.     Generating the 3d model geometry: There are two methods of creating a structure data in staad.
a.     Using the command file also called “The staad editor method”.
b.    Using the graphical user interface (GUI).
   We have done our whole of the programming with the help of GUI method because it is easier and much advance tool of staad.
                 The model of the framed structure is generated in staad by Snap Node/Beam dialog box which appears when we select the grid from the top menu bar. Then the nodes and beams are created by this command at the suitable distances as per our need.
Fig. The model of structure with all the beams and nodes.

3.     Assigning the material: As after creating the beams and columns we will assign material to them as we require. Our design is concrete design hence we have assigned the concrete material to the beams and columns.

4.     Specifying member properties: The properties of the beams and columns is their size(width, depth of cross-section).So with the help of this command we have inputted the different properties (as circular, rectangular, square) and assign these properties to specified members.   
Fig. 3d Rendered model after specifying the properties to member.

5.     Specifying material constants: As we assigned the concrete material so by default we have the constants of concrete and we don’t need to use this command separately. Or if we need to change the constants we can do so by this command.

6.     Specifying member offset: As  default in the staad design of model and after assigning properties, the staad takes the beams and columns center to center and if we want to have beams end to end over the columns then we use Beam      offset command.
                                                                   
                                                     
        Fig. Beam before offsetting                             Fig. Beam after offsetting
7.     Printing member information:  As if we would like to get a report consisting of information about all the members including start and end joint numbers, members length in staad output file then we use this command as by going to Commands      Pre-Analysis Print     Member information from top menu bar.        

8.     Specifying Supports: The supports are first created (as we created fixed supports) and then these are assigned to all the lowermost nodes of structure where we are going to design the foundation.
Fig. The model with the fixed supports.

9.     Specifying Loads: This is done in following two steps :
a.     Firstly creating all the load cases.
b.    Then assigning them to respective members and nodes.
The staad program can produce all types of loads and can assign them to the structure. It also has the capability to apply the dead load on the structure. There are some definitions of loads which are firstly created according to IS codes before creating specific load cases (As Seismic or wind load). Here below are some types of loads as we have assigned.
a.     Dead Load: The load coming on framed structure due to self weight of beams, columns, slabs or walls. This load will act as uniformly distributed load over the supporting beams.
3.05 KN/m

Fig. The dead load coming on beam no. 31 having UDL of -3.05 KN/m.

b.    Live Load: The live load comes on structure due to extra necessary things in the house. There will be different Live Loads acting in the structure due to different uses of building. As here we have used various types of different live loads in our structure.
i.                   The Floor load coming on the beams form the trapezoidal load on one longer beam of floor area.



Fig. Trapezoidal load coming on beam due to floor load.
ii. The Floor load coming on the beams form the triangular load on one shorter beam of floor area. 
 
Fig. Triangular Load coming on beam due to floor load.

iii.              There will be some moments coming on beam these can also be applied on beams. As in our structure the moments are coming due to the cantilever slab due to balcony on back side of house on the ground floor and top floor.
33.75 KN-m/m Acting in GX Dir.

Fig. The moment coming on beam of top floor due to balcony.

c.      Wind Load: The Wind load coming on structure is defined firstly by load definitions. Then inputting the required data. And after that the load is created to apply in suitable direction.
Wind Load designed for wind velocity of 39m/s

Fig. The wind load acting on back wall of house.

d.    Load Combinations: The load combinations have been created with the command of auto load combinations. By selecting the Indian code we can generate loads according to that and then adding these loads. These combinations do not required to be assigned on members.
Hence all the loads are assigned on the structure we will move towards forward step.

10.                         Specifying the analysis type: Before doing the analysis for the loads we require specifying analysis command which we need is linear static type. Choosing statics check, we will add this command.

11.                         Post-Analysis print command: As we require obtaining member end forces and support reactions written in the output file. By clicking on post-analysis a dialog box will open then by clicking define command, we can add the commands which we need and can assign them to members for which these will be analyzed.
12.                         Run Analysis: The structure will be analyzed to the loads and this command will also show if there is any warning or error.

13.                         Post-Processing mode: We can see results in this mode. The deflection, bending moment, shear forces and reactions on supports can been on the structure with values. The figures shown below are under Dead Load. We can also see figures under Live Load or other which we want.
Fig. The bending moments on each beam and column.
Fig. The Displacement on each beam and column.
Fig. The shear force in Y-Direction.
Fig. The Stresses on each beam and column.



After doing all the structural analysis of our structure, we have designed it to find out the steel used for the reinforcement for the columns and beams.
By selecting the code IS: 456 2000 for the concrete design we will then define parameters for our design as:
1.     Clear: Providing clear cover to beams and columns as inputted .04m in our case.

2.      FC: This is the Compressive strength of concrete as 25000 KN/m2.

3.      FY Main: This is the yield strength of the main reinforcement steel as 415000 KN/m2.

4.     FY SEC: The yield strength of secondary reinforcement steel as 415000KN/m2.

5.     MAXMAIN: The maximum bar size to be provided for main reinforcement as 25mm.

6.     MAXSEC: The maximum bar size to be provided for secondary reinforcement as 25mm.

7.     METHOD: To consider minimum eccentricity about one axis at a time this command is selected.

8.     MINMAIN: The minimum bar size to be provided for main reinforcement as 10mm.

9.     MINSEC: The minimum bar size to be provided for secondary reinforcement as 8mm.

10.             MMAG: The factor by which the column design moments will be magnified as 1.5 is taken in our project.

11.             REINF: This command is used for selecting the tied or spiral columns we have used tied columns.
12.             TORSION: This will be selected if we want to have design for torsion.

13.             TRACK: The track parameter is selected as per need it gives three different options.
After giving all these inputs we will now give commands as for the design of beams and columns. These are selected once added and then assigned to the structure to appropriate components.
Then the structure is again analyzed for the generation of report.
The Final Report that we have generated actually of our staad project is consisting of 550 pages (as generated for all beams and columns) and hence here we have given some specific results of that report as shown in figure below the different beams with Beam No’s:
FIG. The Structure showing different beams and columns with their no’s.
BEAM NO.29   DESIGN RESULTS
M30                    Fe415 (Main)               Fe415 (Sec.)
LENGTH:  3840.0 mm      SIZE:   300.0 mm X 300.0 mm   COVER: 25.0 mm  SUMMARY OF REINF. AREA (Sq.mm)
SECTION      0.0 mm      960.0 mm     1920.0 mm     2880.0 mm     3840.0 mm
     TOP           530.92        193.78           0.00                165.90           436.72
  REINF.      (Sq. mm)      (Sq. mm)      (Sq. mm)      (Sq. mm)        (Sq. mm)
 BOTTOM      293.47        266.71          165.90            1 65.90           165.90
    REINF.      (Sq. mm)      (Sq. mm)      (Sq. mm)      (Sq. mm)      (Sq. mm)
                        SUMMARY OF PROVIDED REINF. AREA
SECTION      0.0 mm      960.0 mm     1920.0 mm     2880.0 mm     3840.0 mm
   TOP        7-10í          3-10í             2-10í                3-10í              6-10í
 REINF.     1 layer(s)    1 layer(s)    1 layer(s)        1 layer(s)          1 layer(s)
     BOTTOM     4-10í         4-10í           3-10í             3-10í                  3-10í
   REINF.    1 layer(s)   1 layer(s)    1 layer(s)       1 layer(s)         1 layer(s)
SHEAR REINF. 2 legged 10í  @ 120 mm c/c.
SHEAR DESIGN RESULTS AT DISTANCE d (EFFECTIVE DEPTH) FROM FACE OF THE SUPPORT:
SHEAR DESIGN RESULTS AT   415.0 mm AWAY FROM START SUPPORT
     VY = 14.27  MX = 25.80  LD = 2
     Provide 2 Legged 10í  @ 120 mm c/c
SHEAR DESIGN RESULTS AT   465.0 mm AWAY FROM END SUPPORT
     VY = -18.48  MX = 25.11  LD = 2  
  Provide 2 Legged 10í  @ 120 mm c/c
COLUMN NO.1  DESIGN RESULTS
M30                    Fe415 (Main)               Fe415 (Sec.)
LENGTH:  3000.0 mm   CROSS SECTION: 300.0 mm X 300.0 mm  COVER: 40.0 mm
** GUIDING LOAD CASE: 3 END JOINT: 2 TENSION COLUMN
REQD. STEEL AREA   :      720.00 Sq.mm.
REQD. CONCRETE AREA:    89280.00 Sq.mm.
MAIN REINFORCEMENT : Provide   4 - 16 dia. (0.89%,    804.25 Sq.mm.)
                        (Equally distributed)
TIE REINFORCEMENT: Provide 8 mm dia. rectangular ties @ 255 mm c/c.
SECTION CAPACITY BASED ON REINFORCEMENT REQUIRED (KN-M)
Puz: 1429.38  Muz1: 30.97  Muy1 : 30.97
INTERACTION RATIO: 0.00 (as per Cl. 39.6, IS456:2000)
SECTION CAPACITY BASED ON REINFORCEMENT PROVIDED (KN-M)
   WORST LOAD CASE: 3
END JOINT: 37 Puz : 1454.46  Muz : 33.58  Muy : 33.58   IR: 0.01

COLUMN N O. 2  DESIGN RESULTS
M30                    Fe415 (Main)               Fe415 (Sec.)
LENGTH:  3000.0 mm   CROSS SECTION:  210.0 mm X  400.0 mm  COVER: 40.0 mm
** GUIDING LOAD CASE: 2 END JOINT: 2  TENSION COLUMN
REQD. STEEL AREA   :      692.52 Sq.mm.
REQD. CONCRETE AREA:    83307.48 Sq.mm.
MAIN REINFORCEMENT: Provide   8 - 12 dia. (1.08%,    904.78 Sq.mm.)
(Equally distributed)                  
TIE REINFORCEMENT: Provide  8 mm dia. rectangular ties @ 190 mm c/c
SECTION CAPACITY BASED ON REINFORCEMENT REQUIRED (KN-M)
Puz : 1340.20   Muz1 : 49.46   Muy1 : 23.50
INTERACTION RATIO: 0.99 (as per Cl. 39.6, IS456:2000)
SECTION CAPACITY BASED ON REINFORCEMENT PROVIDED (KN-M)
WORST LOAD CASE: 3
END JOINT: 38 Puz : 1403.40  Muz : 52.40   Muy : 24.34   IR: 0.01

COLUMN N O. 10  DESIGN RESULTS
M30                    Fe415 (Main)               Fe415 (Sec.)
LENGTH:  3000.0 mm   CROSS SECTION:  400.0 mm X  210.0 mm  COVER: 40.0 mm
** GUIDING LOAD CASE: 2 END JOINT: 25  TENSION COLUMN
REQD. STEEL AREA   :      672.00 Sq.mm.
REQD. CONCRETE AREA:    83328.00 Sq.mm.
MAIN REINFORCEMENT: Provide   8 - 12 dia. (1.08%,    904.78 Sq.mm.)
                                                                   (Equally distributed)                   
   TIE REINFORCEMENT: Provide 8 mm dia. rectangular ties @ 190 mm c/c
SECTION CAPACITY BASED ON REINFORCEMENT REQUIRED (KN-M)
Puz : 1334.09  Muz1 : 19.46   Muy1 : 40.19
INTERACTION RATIO: 0.12 (as per Cl. 39.6, IS456:2000)
SECTION CAPACITY BASED ON REINFORCEMENT PROVIDED (KN-M)
WORST LOAD CASE: 2
   END JOINT: 25 Puz : 1403.40   Muz :  24.51   Muy : 52.82   IR: 0.09
COLUMN N O. 62 DESIGN RESULTS
M30                    Fe415 (Main)               Fe415 (Sec.)
LENGTH: 6000.0 mm CROSS SECTION: 424.3 mm dia. COVER:40mm
** GUIDING LOAD CASE:    3 END JOINT:    32  TENSION COLUMN
REQD. STEEL AREA   :     1130.97 Sq.mm.
REQD. CONCRETE AREA:   140240.66 Sq.mm.
MAIN REINFORCEMENT: Provide   6 - 16 dia. (0.85%,   1206.37 Sq.mm.)
(Equally distributed)
TIE REINFORCEMENT: Provide  8 mm dia. circular ties @ 255 mm c/c
SECTION CAPACITY BASED ON REINFORCEMENT REQUIRED (KN-M)
Puz : 2245.26 Muz1 : 63.22  Muy1 : 63.22
INTERACTION RATIO: 0.01 (as per Cl. 39.6, IS456:2000)
SECTION CAPACITY BASED ON REINFORCEMENT PROVIDED (KN-M)
WORST LOAD CASE:     3
END JOINT:66  Puz : 2267.71   Muz : 65.58   Muy : 66.32   IR: 0.02

COLUMN NO. 261  DESIGN RESULTS
M25                    Fe415 (Main)               Fe415 (Sec.)
LENGTH: 3000.2 mm CROSS SECTION: 424.3 mm dia.  COVER: 40 mm
** GUIDING LOAD CASE: 2 END JOINT: 65 TENSION COLUMN
DESIGN AT JOINT NO.      65
CASE 1: MINIMUM ECC. ABOUT Y CONSIDERED
DESIGN FORCES (KN-M)
DESIGN AXIAL FORCE (Pu): 29.8
                                     About Z         About Y
   INITIAL MOMENTS                                       :   7.6             13.8
   MOMENTS DUE TO MINIMUM ECC.         :    0.00                0.60
   SLENDERNESS RATIOS                               :        -                     - 
   MOMENTS DUE TO SLENDERNESS EFFECT:   -                     - 
   MOMENT REDUCTION FACTORS             :         -                     - 
   ADDITION MOMENTS (Maz and May)      :           -                     - 
          TOTAL DESIGN MOMENTS                :      7.64                34.51
REQD. STEEL AREA  : 1613.53 Sq.mm.
INTERACTION RATIO: 1.00 (as per Cl. 39.6, IS456:2000)
CASE 2: MINIMUM ECC. ABOUT Z CONSIDERED
DESIGN FORCES (KN-M)
DESIGN AXIAL FORCE (Pu)  :  29.8
                                                                             About Z         About Y
INITIAL MOMENTS                                      :          7.6            13.8
MOMENTS DUE TO MINIMUM ECC.           :         0.60            0.00
SLENDERNESS RATIOS                                  :            -               - 
MOMENTS DUE TO SLENDERNESS EFFECT   :       -               - 
MOMENT REDUCTION FACTORS                 :           -               - 
ADDITION MOMENTS (Maz and May)           :            -               - 
TOTAL DESIGN MOMENTS                           :         7.64           34.51
REQD. STEEL AREA   :     1613.53 Sq.mm.
INTERACTION RATIO: 1.00 (as per Cl. 39.6, IS456:2000
 CASE 1: MINIMUM ECC. ABOUT Y CONSIDERED
DESIGN FORCES (KN-M)
DESIGN AXIAL FORCE (Pu) :  -6.8
                                                                                      About Z         About Y
INITIAL MOMENTS                                    :          0.8                 0.9
MOMENTS DUE TO MINIMUM ECC.       :            0.00            0.18
SLENDERNESS RATIOS                                   :               -               - 
MOMENTS DUE TO SLENDERNESS EFFECT  :     -               - 
MOMENT REDUCTION FACTORS            :              -               - 
ADDITION MOMENTS (Maz and May)      :              -                - 
TOTAL DESIGN MOMENTS                :                  0.81            0.91
REQD. STEEL AREA   :     1130.97 Sq.mm.
INTERACTION RATIO: 0.03 (as per Cl. 39.6, IS456:2000)
   CASE 2: MINIMUM ECC. ABOUT Z CONSIDERED
DESIGN FORCES (KN-M)
DESIGN AXIAL FORCE (Pu)  : -6.8
                                                                                    About Z         About Y
INITIAL MOMENTS                                            :     0.8             0.9
MOMENTS DUE TO MINIMUM ECC.              :    0.18            0.00
SLENDERNESS RATIOS                                            :     -               - 
MOMENTS DUE TO SLENDERNESS EFFECT   :     -               - 
MOMENT REDUCTION FACTORS                            :     -               - 
ADDITION MOMENTS (Maz and May)                       :     -               - 
TOTAL DESIGN MOMENTS                             :    0.81            0.91
REQD. STEEL AREA   :     1130.97 Sq.mm.
INTERACTION RATIO: 0.03 (as per Cl. 39.6, IS456:2000)
CRITICAL CONDITION : MAXIMUM AREA OF STEEL REQUIRED OF THE 4 CASES.
REQD. STEEL AREA   :     1130.97 Sq.mm.
REQD. CONCRETE AREA:   140240.66 Sq.mm.
MAIN REINFORCEMENT: Provide   6 - 16 dia. (0.85%,   1206.37 Sq.mm.)
                                                                    (Equally distributed)                  
   TIE REINFORCEMENT: Provide 8 mm dia. circular ties @ 255 mm c/c
SECTION CAPACITY BASED ON REINFORCEMENT REQUIRED (KN-M)
Puz :   1929.72   Muz1 :     59.85   Muy1 :     59.85
INTERACTION RATIO: 0.48 (as per Cl. 39.6, IS456:2000)
SECTION CAPACITY BASED ON REINFORCEMENT PROVIDED (KN-M)
WORST LOAD CASE: 2
END JOINT: 65 Puz : 1952.34 Muz : 61.72  Muy :  63.12  IR: 0.46
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