Structural Modelling using Etabs 2018
Pease find the attached Answer sheets
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 beamsand columns etc.
1) Open the ETABS software click on new Modal and select the units, data base, steel design code IS 800 and concrete design code IS 456.
2) In new model quick templates Click Custom grid spacing - Grid system data give grid spacing in X and Y direction In X direction of grid and Y direction of grid
3) Click quick start rectangular grid i,e Story data enter the story up to 7 and height 3m and plinth 3m. all story will be same as story1.
4) Define material properties -Add new material property – Indian – concrete and Grade M30 same way for steel property.
5) Define Section property for beam - size and grade and cover to be specify same way for columns and slab.
6) Define Load Patterns – dead load live load brick wall load and seismic load in Eqx + & - ve and Eqy + & - ve
7) Fixe the columns by clicking Quick draw column by selecting C300x600 and 300x900 at grid junction by clicking
8) Fixe the Beams by clicking Quick draw beam by selecting B300x450 and 300x600from grid to grid clicking
9)Fixe the slab by clicking Quick draw floor/ wall by selecting Slab150 clicking center of four beams
10) Fixe the shear wall by clicking draw wall by selecting wall 300 from grid to grid clicking
11) Assign the Pier label P1, P2, up to P12.
12) Assign the Floor load – live load on slabs 2KN/m2 and roof slab 1.5KN/m2 separately
13) Assign the brick wall load 10KN/m on beams by selecting beams
14) Define the mass source
15) Define the Load Combination – Add default design combs
16) Define diaphragms
17) Analysis -Check Modal by selecting all – click OK
18) define Response spectrum in x and y dircetion
19) Run analysis
20) Display Show table - Base Reactions
21) Reaction in x and y direction for find the scale factor
In X direction 3575.97/1742.91 = 2.052 9806.65 x 2.052 = 20123.25
In y direction 3575.97/1668.25 = 2.144 9806.65 x 2.144 = 21025.46
22)Corrected the scale factor in x and y direction
22)Display the maximum drift Eqx and Eqy in x and y direction respective
23) Minimum shear wall requirements and maximum axial load ratio for shear wall
Reaction in x direction for Eqx
Total reaction = 3575.97 for wall
Reaction in x direction for Eqx
Total reaction = 4279.37 for wall
4279.37/3575.97 = 1.196 > 0.7 Hence minimum shear wall is satisfied
24) Maximum axial load ratio for column
Reaction in x direction = 263.3Kn
Reaction / column size x fck
263.3 x 1000/ 300x300x25 = 0.059 < 0.4
Pease find the attached Answer sheets