Modelling of 25 storey building with the specified properties using ETABS

Aim:

To Model a 25 storey building on ETABS 2019 with structural properties as specified below. Ground floor or plinth floor level can be taken at a height of 1.5 metres from the base. Each of the successive 25 storeys has a storey height of 3 metres.

Procedure:

Step 1:

Open 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.

Choose the Built-in settings option and select the display units and codes.

Step 2:

After the model initialization.Select Grid and Story inputs from the New model quick templates dialogue box.

In this dialogue box choose custom grid spacing and custom story data which is used to provide the inputs specified above.

Enter X grid data 5 nos at a distance of 4 metre and Y grid data as 4 nos at a distance of 4 metre.

Click on the story data dialogue box,add a story and add 21 more story.

Keep height for all the story as 3m and plinth level as 1.5m.

Make 1st story as Master story.

Kepp all the stories as similar to 1st story.

Select material properties under the define tab.

Define the materials of concrete M30 grade and steel of transverse reinforcement as 415 grade and Longitudinal reinforcement as 500 grade.

Select Section properties under the define tab.

Click on the frame section and create a new property as beam and input the values as 300X400 mm.

After the define the properties for the column as 800X800mm and Slab thickness as 150mm.

Column of 800X800mm:

Slab of 150mm thick

Draw Column of size 800 mm X 800 mm at the intersection of the horizontal and vertical grid and beams

with Quick draw tool.

Draw the floor of 150 mm thick by using quick darw floor tool.

Select the assign and click on joint select pinned support.

Fix the pinned supports at the base.

Define the load patterns:

Click on the define tab and click on the load patterns.

Define the loads like dead load ,live load,brick wall,earth quake load in x direction and positive x and negitve x and same loads in the Y direction also. Mention the IS code of recpective loads.

Click on the modify lateral load,Set range from base to 25th storey and sesimic zone as IV,Importance factor is 1.25 and time period as 0.5sec.

Do the same for all th earthquake loads.

Assigning of loads:

Select the similar stories.

Click on the shell load under the assign tab.

Click on the live load and give the value as 3Kn/m^2.

Click on apply.

For the roof we will take only 50% of the live load.

Simillarly we need to add the live load of 10 Kn/m^2 on all the beams.

Fot that select all the beams from select-object type-beams.

Goto the Frame load and click on the distributed load and enter the value as 10 Kn/m^2.

Goto mass source under the define tab.

Modify the mass source and tick mark the required loads.

Add load patterns assign to the model.

Define the load cases:

Click on the load combinations.

Click on the add default design combos.

Creating diaphragm:

The earthquake loads acts on the centriod of the building for that we have to add diaphragm.

Goto Assign ,click on the sheel ,Click on the diaphragm.

Click on ok.

Click on the analyze tab and check the model.

Click ok.

Run the analysis or click on F5.

Result: