Analysis and concrete Design of
structure with
STAAD.Pro V8i
BHANU PRATAP
CIVIL ENGINEERING
T.R.A.M.I.E.T, NER-CHOWK, MANDI
HIMACHAL PRADESH UNIVERSITY
Abstract: This
report includes the concrete design of beams and columns of a two storey
building. The whole procedure of analysis & designing is done in Staad.Pro.
The process of designing is defined in the best suitable manner it can be. All
the specific results are also shown in the end.
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.
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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