Structural Modelling using Etabs 2018

ANSWER 1.

AIM : To model and analyze the G+7 residential building from the given architectural drawings using the ETABS 2018.

INTRODUCTION :

Introduction:-

• ETABS is an engineering software product that caters to multi-story building analysis and design.
• Modeling tools and templates, code-based load prescriptions, analysis methods and solution techniques, all coordinate with the grid-like geometry unique to this class of structure.
• Basic or advanced systems under static or dynamic conditions may be evaluated using ETABS
• ETABS modeling is the generalization that multi-story buildings typically consist of identical or similar floor plans that repeat in the vertical direction.
• Modeling features that streamline analytical-model generation, and simulate advanced seismic systems.
• Once modeling is complete, ETABS automatically generates and assigns code-based loading conditions for gravity, seismic, wind, and thermal forces.

PROCEDURE:

STEP 1.

• First we have to open the etabs software.
• Next click on the file option at the left side top corner and select the new model, as shown below.
• After selecting the new model the new tab opens, in that tab we have to select 'Use Built-in Settings with' option, as shown below.
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• After selecting the new model the new tab opens, in that tab we have to select 'Use Built-in Settings with' option, as shown below.
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• After setting the model Initialization the templates tab will opens and, select the Grid only and press ok.
• Next we need to do the settings in Grid system data, as shown below.

• Next we need to add the stories upto 7 story in the Story Data, as shown below.
• The 7 stories are added in the Story Data, as shown below.

Step:-2

• Next the plan views are visible in the etabs screen, as shown below.
• Next we need to open the 3d-view, as shown in the below figure

Step:-3

• Next we need to define option and select material properties, as shown below.

• After selecting the material properties the new tab appears, then we add new materials by selecting the Add new material option, as shown below.
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  Step:-4

  • Now we need to add material type as concrete and grade as M25.
  • Next we need to check the material property data, as shown below.

  Step:-5

  • Now we need to add new material type as rebar and grade as HYSD Grade 415.
  • Next we need to check the material property data, as shown below.

  Step:-6

  • Now we need to add new material type as rebar and grade as HYSD Grade 500.
  • Next we need to check the material property data, as shown below.
  

• Step:-7

  • Now we need to select the section properties and click on the frame sections, as shown below.
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  • Step:-8

  • After selecting the frame sections the new tab will be visible, in that we need to select the Add New Property, as shown below

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    After selecting the Add New Property, the new tab appears.
  • In that new tab we select the Rectangular shape type in concrete, as shown below.
  • 
    • Next the frame section property data will be visible, In that we add beam size as B250x500 & B300X600, as shown below.
    • Next we need to select the Modify/Show Rebar option as shown below.
    • After selecting the Modify/Show Rebar option the new tab appears, In that we select the design type as M3 Design only (Beam).
    • Next we select longitudinal bars with the grade of HYSD500.
    • Next we select Confinement bars with the grade of HYSD415.
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  • 

  • Step:-9

    • Next we have to add the column size as COL 400X400 & COL 450X600in the frame section property data, as shown below.
    
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Step:-10

• Next we select the slab section option from the section properties, as shown below
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  • Next the slab properties tab will be vissible, In that we select the Modify/Show Property option, as shown below.
  • After selecting the Modify/Show Property option, the new tab appears.
  • In that we need to put the slab name as Slab 125, it means slab with the thickness of 150mm.
  • And we take the concrete grade as M25, as shown below.
  • Next we have to click the ok option.

• • Now we take the slab thickness separately for staircase with the thickness of 200mm, as shown below

• • Step:-11

    • Next we have to add the wall properties in the wall property data, as shown below

Step:-12

• Next we need to add the columns using the Quick draw columns option, as shown below.

Step:-13

• Next we need to add the beams using the Quick draw beams option, as shown below.

• • • • Step:-14

        • Next we need to add the secondary beams using the Quick draw beams option, as shown below.

Step:-15

• Next we add the shear walls in required locations in the residential building, as shown below.

Step:-16

• Next we need to add the slabs using the Quick draw floor/wall option, as shown below.

Step:-17

• Now we go to the base plan and select all base joints.
• Next we select the Restraints from joint option, as shown below.

• Now we need to select the fixed joint and click on apply and then click on close button, as shown below.

Step:-18

Next we need to select the load patterns from the define option, as shown below.

• Now we should add Dead load, live load, Brickwall load, and earthquake load, as shown below.

Step:-19

• Next we need to select the distributed load from the frame loads, as shown below.

• Then after the new tab will appear, In that we select load pattern as Brickwall, and we take uniform load as 5 kN/m and then click on the apply button and close.

Step:-20

• Next we have to click on the assign option and then select shell loads, from the shell loads we select the Uniform option, as shown below.

• Here we apply the 2.5 3kN/m2 live load for the staircase portion, varanda, and lift core area.
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• Next we apply the 2kN/m2 live load for the remaining portions in the residential building, as shown below..
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• Step:-21

  • Next we have to select live load reduction factors from the design option, as shown below.
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  • Now we add the reduction factor by decreasing 10% from 1st floor to 7th floor, as shown below.
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  • Step:-22

    • Next, from the define option we select the mass source, as shown below.
    • 
    • Next we add the load patterns in the Mass Source Data, as shown below.
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Step:-23

• In the select option we select object type option, as shown below.

• After selecting the object type option, the new tab will be visible, In that select the floors and click on the select button and close.

• Next we have to select the Diaphragms from the shell option, as shown below.
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• After selecting the diaphragms the new tab will appear, in that select D1 and click on the apply button and close.

• 

• STEP 24:

RESULT:

• Next, from the display option we select the show tables option, as shown below.
• After selecting the show tables option the new tab will be visible.
• Now we select the Modal Participating Mass Ratios and click on the ok button, as shown below.
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Step:-25

• Next we select the Story response plots from the Display option, as shown below.
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• The story response for maximum story drifts at X & Y directions, should not be more than 4%.
• MAXIMUM STORY DRIFT OF EQX= 0.000884
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• MAXIMUM STORY DRIFT OF EQY =0.00136

Step:-26

• Next we open the select plan view tab and select the base floor, as shown below.
• Next we have to open the reactions tab, then we select the eartquake load towards X-direction(EQX) in the load case, then click on the ok buttion as shown below.
• 
• • Now the base shear reactions will appear, as shown below.
  • When we divide the base shear taken up by the shear wall divided by the total base shear of building will get the % of the shear forces taken up by the shear wall.
  • And if that is less than 80%, then the more shear walls we need to add to the structure.

  

• RESULT:-

  • The G+7 residential building has been modelled and analyzed successfully using the ETABS 2018.
  •