Modelling of 25 storey building with the specified properties using ETABS

Question :

Model a 25 storey building on ETABS 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.

Structural Element Sizes

• Beams : 300 × 400 mm
• Columns : 800 × 800 mm
• Slab : 150 mm thick

Material Properties

• Grade of Concrete : M30
• Grade of Steel Reinforcement Bars : Fe 415

ANS

Aim : Model a 25 storey building on ETABS 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.

Apparatus : Etabs installed software , model Initilazation , Grid system , Draw tool bar, Select , Asign , define , View , edit.

Procedure :

• Start etabs software in model Initialization use built in system setting Display units as metric , steel section Database indian , steel Design code as IS 800 : 2007 and concerte design code is IS 456:2000
• Click OK to display the grid settings

Fig 1

Fig 2

• In Grid settings set grid in X direction as 4 meter in each spacing and y direction as 4 meter as shown in below picture

Fig 3

• Click on story Dimension custom spacing and click on edit story Data
• Click Story as 25 store and distance as from floor to floor as 3 meters
• Master story as first floor and remaining as similar to first floor
• etabs will automatic generate the height of the building as shown in fig 4

Fig 4

Fig 5

Fig 6

Fig 7

• The figure 8 shows the 3d view of 25 floors and the plan view of the 1st floor in a single frame this is happen after the all grid setting and the height settings are done

Fig 8

• To add the material property go to the define click on define material and click on add new material
• Add the region as Indian , material type concrete , standerd indian , grade of concrete as M30

1. The lightweight modification factor (l) recommended by the American Concrete Institute (ACI 318-08) shear design provisions was computed and ranged from 1.21 to 2.71 for all beam specimens.

• To add the material property go to the define click on define material and click on add new material
• Add the region as Indian , material type concrete , standerd indian , grade of Steel as HYSD Grade 500
• Etabs will automatic generate the required data for the design code

• To add the material property go to the define click on define material and click on add new material
• Add the region as Indian , material type concrete , standerd indian , grade of for contailment bar as HYSD415
• Etabs will automatic generate the required data for the design code
• We use only the non linear material

For shear reinforcement we use fe415

• For Beams and column go to define and section properties frame section
• Click on add new property material
• Click on concrete
• Specify the name property as column and assign the size of column as 800mm X800 mm
• material type as concrete
• Also gave the dimension of the column as 800mm X800 mm

1. Due to tracking takes place we take only 0.35 as per Is 1893
2. Read clause 6.4.3.1 for structural analysis of beam the moment of inertia is about 35 %

• Click on define and select the slab
• Select the Slab property data and provide property data as slab 150 and material as M30
• Click type as slab and thickness of slab as 150mm

• For placement of column click on qucik place of column in left side of the toolbar
• In that select the column size as prescribed 800mmX800mm
• Etabs will automatically get the size of the column and the placement of the column on the grid will be done by left clicking
• As shown as figure below

This is the sectional view of the Building below figure

• At the base of the building the pin joint are provided as shown in figure below

• For the seismic load pattern the load are to added like the Dead load , live load , brick load , for the Dead load load value is 1 and for the live load 0 and brick load 1
• Also add earthquake load in X direction ,
• Earthquake load in -X direction
• Earthquake load in + X direction
• Earthquake load in -Y direction
• Earthquake load in +Y direction
• Earthquake load in Y direction

• Click on the direction of modify the Direction and the eccentricity are in X direction and the Responce reduction factor as 5 and soil type is zone II
• The time period is taken as 1.22 sec as formulated in IS 1893:2016
• shown in figure below

The load acting of the bulding in the direction of the gravity in -z direction

The animation play of the building behavior after the asign of load and the vibration of the building in annimation