Structural Modelling using Etabs 2018

The architectural drawings for a G+7 residential building in zone 5 has been provided. The floor plan is the same for all 7 floor levels. Possible column positions have also been provided. Conceptualize a framing plan layout and then model the building in Etabs. The following architectural drawings have been provided:

• Typical floor plan – The location and thickness of the brick walls and the use of the
  space (for estimating live load) can be obtained from this plan
• A building section through the staircase and lift core is provided
• Parking layout in the ground floor – the column/shear wall arrangement must not
  obstruct entry/exit of vehicles.
  The following loadings are to be taken into account:
• Brickwall made of AAC blocks
• Finishes – floor tiles of 75 mm thickness
• Live loads as per IS 875 part 2
• Water tank of 20 KL above the staircase at Mumty level
• Lift Machine room at mumty level above lift core

The structural model must comply with provisions of IS 1893 and IS 13920.
Run a modal response spectrum analysis and check analysis results of the etabs model for inter-storey drift requirements, vertical & planar irregularities, minimum shear wall requirements,maximum axial load ratio for column and shear walls, effective moment of inertia for beams
and columns etc.

Please note that the column positions shown in the architectural typical floor plan are only to provide an initial starting point for modelling. Participants will have to change its size, introduce shear walls, and add new vertical elements after running the analysis. You will have to run the analysis multiple times until a structural model is obtained that meets structural code requirements without compromising architectural functions. Also, there is no one ‘correct’ structural system for this challenge. There can be multiple possible solutions for this problem.

Aim:

Firstly we have to model and analyse G+ 7 residential plan for a given architectural drawing using e-tabs 2018

Procedure :-

• Open the ETabs software.
• Click the file menu and choose to create a new model option.
• After choosing a new model a dialogue box will appear as Model Initialization.

• Now we have to choose the build in settings option and select the display units and codes
• New dialogue box will appear named new model quick templates and then we will select custom get spacing and custom story data

• After initialisation model select grade and story inputs for new model kit template dialogue box
• In the dialogue box choose great spacing and customs story data which is used to provide the input specified above
• Now we have to edit stories by using the user defined story input there will be 26 stories are incorporated, story one has been labelled as a master story and the all the above stories are similar

• Now we have to add story high test 3M and the number of added story as 4
• So after adding the stories 7 stories are successfully created
• Then we have to select material properties under define tab
• Now we have to add material type as concrete and grade as m25 and then we need to check the material property data
• Then we need to add material type as river and grade as HYSD 415 ,HYSD 500 and we need to check the material property data

• Now we have to create a new property as Beam and input values as 250 X 450,
• Select the modify / show river in reforcement option and select the M3 design only beam then select REBAR as HYSD 415

• Now we have to create a new property as Beam and input values as 300X500
• Select the modify / show river in reforcement option and select the M3 design only beam then select REBAR as HYSD 415

• Now we have to create a new property as Beam and input values as 400X400
• Select the modify / show river in reforcement option and select theP- M2,M3 design only beam then select REBAR as HYSD 415

Now we have to create a new property as Beam and input values as 400X650

Select the modify / show rebar in reforcement option and select theP-M2, M3 design only beam then select rEBAR as HYSD 415

• Now select section property under define tab and select slap sections and select add new properties in slab properties
• Using the membrane properties slab size 125 mm has been added to the list
• Now the membrane property will help to consider only slab weight and floor weight in analysis of the structure while these stiffness component of lunch advantage are considered during calculation
• Using the membrane property slab sides 200 mm has been added to the list of the staircase and the membrane property will help to consider only slabet and the floor weight is analysis of structure while the stiffness component of the flanch advantage are considered during calculation

• Now we have to add wall properties in the wall property data

• Now draw Wall data as thickness of the wall as 250 mm, 300 mm material M25

• Now draw a column of size 400 X 400 ,400x650 at the intersection of the horizontal and the vertical grids and beam with kick draw column keep all the stories on

• Now draw beam of size 250 X 450 mm at the intersection of the horizontal and the vertical great and beam with quick draw beam keeping all the stories on

• Beams are Successfully added to the structure.

• Then add a secondary beam and sgear wall to the required structure

• Now draw the slaps of thickness 125 mm
• Now we go to the base plan and select all the joints now we have to select the resistance joint option as shown

• Now define the load patterns and click on the define tab and click on the load patterns
• Define load like that load, live load, brick load, earthquake load in X direction and same loads in white direction mention IS code as respective loads
• Next we need to distribute load from the frame loads and then after the new tab will appear in that case we select the load pattern as brick wall and we take uniform load as 3.5 kN/m
• Next we have to select the assign option and select shell load and select uniform option here we applied 3 KN/m2 load for the staircase option, baranda and the lift core area
• For the live load apply load of 2KN/m2 for the rest of the portion in this slabs and add light load reduction factor for the design option
• The reduction factor as decreased of 10% from 1st to 7th floor
• Now go to the mass source from the define tab and modify the mass course and tick mark the required load
• Now add load pattern and sign the model and insert the dead load as multiplier to one and live load as multiplied to 2.5 and 4 load as multiplier to 1
• Now go to the load cases in define tab and add the load cases
• Now we have to create the diepharagm by going to the sign tab then shell the diepharagm

• We have to check EQ should be close to the RS , We should calculate the

• Now substituting the value from the table ,

At X- direction -> ( 354.657 / 138.167) X 386.089

-> 991.04

At Y- direction -> ( 354.657 / 115.05) X 386.089

-> 1187.96

• Now we put above value as scale factor for Response Spectrum at X and Y direction.

• Now click on display -> show tables -> Analysis result structure output -> model information -> model periods and frequencies.

• Select the Story Response Plot from Display option.

• Story Response for maximum Story Drifts for x and Y direction is as per following.

X- Direction :-

Y- Direction :-

• Next we open the Base floor in Plan view.

• We have to open Reaction tab, we select the earthquake load towards in X-direction in load case.

• When we divide base shear taken up by shear wall divided by total base shear of Building will get % of shear forces taken by Shear Wall.

Result :-

• Modeled and analyzed G+7 residential plan from given architectural drawings using Etabs 2018.
• Run a modal response spectrum analysis and check analysis results of the etabs model.