Etabs general summarized
procedure for a residential building:
1. File à New Model à Use build-in setting
with:
a.
Display unit: Metric SI
b.
Steel section database:
Indian
c.
Steel design code: IS 800:2007
d. Concrete design
code: IS 456:2000
Click just ‘ok’ on new dialogue
box New Model Quick Template Then two windows appears
with plan and 3-D views
2. Right click
on space of the window à Add/Modify Grid à Modify/Show Grid system Select either Display Grid data on ordinates or Display Grid data on spacing
Study the
architectural plan carefully and arrange grids on X-Grid data and Y-Grid data Remember: even if you insert in feet/in,
it automatically converts
to SI system.
Also, the auxiliary grids can be added or deducted
as required for systematic construction.
3. Modify/Show story data à edit the table
on basis of sectional architectural drawing Note: staircase
cover is also counted
as story
Just below Display to Detailing, you can find options for plan, elevation, 3D view, rotation
and up and down arrow
to jump to any phase of the building and evaluate it.
4.
Define à Define Materials
à Add New Material
a.
Rebar defining:
i.
Region: Indian
ii.
Material type: Rebar
iii.
Standard: Indian
iv.
Grade: HYSD Grade 500
All necessary values are default after version 13 so no need changes.
b.
Concrete defining:
v.
Region: Indian
vi.
Material type: Concrete
vii.
Standard: Indian
viii.
Grade: M20 for slab, beam, footing
but M25 for Column so define
two times
All necessary values are default after version 13 so no need changes.
5. Define à Section Properties à Frame
section à Add New Property Choose section for columns based on Architectural plan
A dialogue box appears:
Property name is to be assigned
as unique name and easily
recognizable
a.
Columnà Material: M25, Depth and Width as per the given size.
Important one is Modify/Show rebar:
Rebar Materials: HYSD500
on both boxes
No. of
longitudinal bars along 3-dr and 2-dr face: 3 and 3 resp. Longitudinal bars size and area: 12
Corner bar size and area:
16 Confinement bar size and area: 8
b.
Beam à (Min. 9”x14”) Material: M20, Depth/Width: 350/230 Modify/Show Rebar:
Design type: Beam
Rebar Materials: HYSD500 on both boxes
Cover to longitudinal rebar: Top bar & Bottom bar = 32.5
6. Define à Section property à Slab
section Modify/Show property:
Slab material:
M20 Slab thickness: 125
7.
Define à Load Pattern (The text in bracket is type of load and numeric value after colon is multiplier)
Dead: 1, Live<=3 and Live>3: 0, Wall load (dead): 0, PWL (dead): 0,
FF (dead): 0, Stair (dead): 0, EQx (seismic-IS 1893:2002): 0 and got to modify lateral
load à do tick only on x-Dr eccentricity for EQx and Y- Dr eccentricity for EQy
8. Define à Mass source à Modify/Show Mass Source: Uncheck
Element self mass and tick specified load pattern:
Live>3 à
0.5, Live<=3 à
0.25, Dead à 0, PWL à 1, FF à
1, stair à 1
9.
Define à Load combination à Add default design combo à Concrete frame
design
10. Define à Diaphragm à add Dn diaphragms for n number
of story in building
11. Modeling:
First study carefully the location of columns, slabs in the architectural plan.
We can use quick draw column and beam for this. Make sure to use the
defined column and beams and slabs available on properties of objects dialogues box.
For balcony, modify/add the grid. Use draw beam, select the defined beam
and draw beams. However,
where in actual
there is no beam in use and yet
we have to apply parapet
wall load, we use virtual beam by selecting ‘none’ under the property
option. This is done to make it convenient
to add parapet loads but in real practice there is no beam.
For base, go to Assign à Joint à Restraint à Fixed support
and use pen symbol to refresh on another window as
well
Use replicate (analogical to copy paste) to copy frames to other story.
This is situated in Edit or use ctrl R.
Use quick draw slab to make slabs.
12. For staircase, study the architectural plan and modify
the grids again.
Better if you leave a small gap between
column and staircase to distinguish different
slab system of column and staircase. Also, add the reference planes for the
landing portions in each floors. [Refer to the
video] Begin from base to each floor on drawing stairs and slabs. If the
building is multistoried, we can
first construct one complete staircase in ground floor and replicate it to other floors.
13. Go to tick mark sign in a box just beneath options and tools à Object assignments à
sections. Here, it is to check if we have fulfilled the required sections
and any errors.
Furthermore, in General à
Extrude frames and extrude shells gives visibility of frames and slabs
used in the modeling.
14. Loading:
Assign à Frame load à
Distributed à choose type of load and value
9” wall in general give wall load 11 applied on beams
Interior wall normally 5.5 or must be calculated. (No loads required
if no wall on grid/beam) [Detail calculation is must for walls
with openings]
Live load 2 for floors (use shell load option), 1.5 on accessible roof else 0.75 and 3 in balcony
[IS 875 part ii]
Live in stair =3, FF = 1.5
Parapet wall = 2.1 FF on shells = 1
Stair = 12 on beams at stairwell
Go to display loads to get to know the clear information of loads so far
applied. Diaphragm: select each plans à Assign à Joint à Diaphragm à
selection
15. Analysis:
Analysis à Check model à Select
all (Make sure no error comes else need to revise model)
Analysis à Run analysis (Notice
the deflections occurring, you may also play the animation)
Now to check if the model is under the criteria
and feasible to be executed
for design,
Display à story response à evaluate
the graphs for seismic loads and story drifts (watch
video for detail)
Display à Show table (Watch
video for detail)
Analyse à
set load case to run à tick
calculate diaphragm center
of rigidity Center
of mass and rigidity
should be <5%
Modal participating mass ratio à 12th Mode must have numeric value near to 1 under sum UX and
UY
Mode 1 & 2:
UX and UY à either of cross value
should be greater than 40% Caution: unlocking
the model deleted
all analysis result but can be regained
again.
16. Design:
Design à Concrete
frame design à view/revise preferences: there must be IS
Design à Concrete
frame design à Select
design combination: design
combinations must be on
right hand side
Design à Concrete frame design à start design check (Here we get detailing of reinforcement)
Display à Force stress Diagrams
à Support reactions à combo àDcon2,
MX and MY
Reference:
1. Saunak Sharma channel, ETABS Tutorial as per IS code in Nepali. Available
on https://www.youtube.com/watch?v=ctppXHxFJNA. Recommended by Sabin Panta, passed out Pulchowk student.
2. https://facebook.com/156218744417668/videos/3257971377761817/
(I have also attached a pdf format document for general instruction for designing a residential building in etabs that was learned from etabs training and other useful videos. Hope, this can help you to work out with basic etabs operation.)
Thank you.
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