Modelling of 25 storey building with the specified properties using ETABS

AIM:

Model a 25-storey building on ETABS with structural properties and to know modeling of a high rise building in ETABS software and to verify the seismic code requirements from ETABS analysis

INTRODUCTION:

By using ETABS software, analyse the building of 25-storey and see how a building behaves under various loads.

PROCEDURE:

STEP1) Install and Launch ETABS 2020

• Install the ETAB software from CSI Website
• After complete the installation, Launch ETABS 2020 software from windows
• ETABS home interface will be open as shown below

STEP2) Create New Model

• Click on New Modal from ETABS home interface
• Select Unit Built in Setting from Modal Initialization dialog box
• Change display unit as METRIC SI
• Region for default material as INDIA
• Steel selection database INDIAN
• Steel design code IS-800:2007
• Concrete design code IS-456:2000 enter OK

STEP3) Create Grids

• A new dialog box opened as New Modal Quick Templates
• Select Custom Grid Spacing and click on the Edit Grid Data
• Modify the X & Y Grid Data from the Grid System Data dialog box and click OK

STEP4) Add Building Storey

• Select Custom Story Data and click on Edit Story Data
• A new dialog box open as Story Data
• Rename the levels of the story 1,2 3,4 as plinth and story 1,2,3 respectively
• Only plinth level height is 5 and all other story height is 3
• Story 1 as master story so, select yes, towards the story 1
• Change story 2 & 3 similar to story 1
• To add more story above the story 3, right click on story 3 and click add story>keep existing story heights
• Provide number of added stories 22 from the dialog box, click OK
• All 25 story are created then change Similar To option as Story 1

STEP5) Define Material

• The grid arrangement of the new modal will open
• Go to Define and click Material Property
• Define Material dialog box will open, click on Add New Material
• Add New Material dialog box will open, select Material Type Concrete and ensure Grade M30 click OK
• Material Properly Data dialog box will open, click OK
• Again, click on Add New Material
• Add New Material dialog box will open, select Material Type Rebar and select Grade HYSD 415 click OK
• Material Properly Data dialog box will open, click OK

STEP6) Add Column, Beam

• Go to Define tab, and select Frame Section from Section Property
• Click on Add New Property from Frame Properties dialog box
• Click on Rectangular Section for Beam from Frame Property Shape Type
• Change the Property Name as B300X400 and Material M30 and section dimension Depth as 400 & width as 300 from Frame Section Property Data, click on Modify/Show Rebar under Reinforcement
• Change Design Type and Rebar Material, click OK
• Again, Add New Property for Column and select Rectangular Section
• Change the Property Name, Material and Dimension and Modify/Show Rebar similarly

STEP7) Add Slab

• Go to Define, Select Slab Section from Section Property
• Click on Add New Property for Slab
• Change the Property Name, Slab Material, Modeling Type and Thikness of Slab

STEP8) Load Pattern

• Go to Define and select Load Patterns
• Add Wall Load as Super Dead type
• Simalry add EQX & EQY Load as Seismic type and select IS-1893:2016
• Modify the lateral load and uncheck the other direction except X for EQX and Y for EQY
• Change the zone as per code 16

STEP9) Define Mass Source

• In Define tab Select Mass Source
• Click on Modify/Show Mass Source
• Check mark only Specified Load Pattern
• Add wall, live and dead load

STEP10) Check Load Case

• Go to Define and select Load Cases
• Check load cases and click OK

STEP11) Load Combinations

• Go to Define select Load Combinations
• Add Default Design Combination
• Check on Concrete Frame Design and Convert To User Combination

STEP12) Draw Column

• Select Quick Draw Column
• And change the
• Select All Stories
• Click on Left Most Y Direction Grid to place the column
• Select all the column and make Replicate

STEP13) Draw Beam

• Select Quick Draw Beam and change the Property
• Click Between Two Columns and place the beam X & Y Direction
• And make Replicate

STEP14) Draw Slab

• Change set plan as Stroy 1 and Similar Stories
• Select Quick Draw Floor icon and change the Property
• Click on the Boundries Of The Grid
• Slab will be created for all floor

STEP15) Assign Load

• Select all Beam
• Assign Frame Load as a Distributed
• Load Pattern Name Wall and Uniform Load 10kn/m
• Similarly select slab
• Assign shell load as uniform
• Load Pattern Name live and Uniform Load 3 kn/m

STEP 16) Add Diaphragms

• Select Slab
• Assign Shell as Diaphragms

STEP 17) Save the Model

• Choose appropriate folder and name to save the model

STEP 18) Run Analyse the Model

• Click on Run Analysis Button
• This will Analyse the structure and provide the result

STEP 19) Check the Model Information

• Click on Tables in Model Explorer tab
• Goto Tables>Analysis Result>Structure Output>Model Information
• Click one by one to all table and check the results

STEP 20) Plots the Story Response

• Goto open Story Response Plot from Display
• Change the Display Type and Case/combo for EQX and EQY
• Verify the Maximum Story Drifts for both EQX and EQY

RESULT:

Criteria		Desirable Solution	Exercise Result
Fundamental Translation natural period	X- direction	4.4 second	4.6
	Y-direction	4.2 second	4.6
Torsional irregularity	IS 1893-2016(Part-1) Table-5	Torsional mode Time period should be lesser than X and Y direction time periods	Yes
Vertical irregularity	IS 1893-2016(Part-1) Table-6 Clause-7	First three modes together should contribute at least 65% in mass participation factor in each principal direction	Yes
		Fundamental lateral natural periods in two principal plane directions are away from each other by at least 10%	No
Inter-storey Drift	IS 1893-2016(Part-1) Clause-7.11.1.1	Storey drift shall not exceed 0.004 times storey height for base shear with no load factors (4x10-3)	Yes