Project 1 - MODELLING, ANALYSIS & DESIGN OF TALL BUILDINGS IN ETABS

Answer of question No. 1

Answer:

Aim : 40hr project on modelling, analysis & design of a state-of-the-art tall building using ETABS software.

Key Highlights:

a. Modelling

b. Loadings & Load combinations

c. Structural Analysis

d. Design of structural members

Key Deliverables

Procedure:

Open New Model in ETABS and Set the unit to metric SI as per Indian Standard

Customise the grid system data and story data and press OK

Go to Define tab Material Properties Add New propertyGive Material type as concrete and Grade as M30 And steel and grade as HYSD 415

Go to Define tab ------ Section Properties ------- Frame Sections ------ Add New Property and Add Column 1000 x 1000 and Beam 750 x 1000

Place Columns, beams, slabs and walls as per the architectural drawing

Go to Edit tab ----- Replicate ----- story and select the story to be replicated and apply

Go to assign tab ------ joint restaints and select fixed support for all the directions and click on apply

Go to define tab ------ Load Patterns and add Dead, Live, Earthquake and Wind Load

Go to define tab ------ Load Combinations ------ Add default design combos------ Concrete frame design

Go to define tab ------ P-Delta options

o to Select tab ------ Properties ------ Frame sections ----- Select beam 750 x 1000

select reactions tab and select earthquake load toward x direction in the load case and click ok. Now base shear reaction will appear

Slab thickness = 150mm

Beam size= 300mm X 300mm

Live load = 2 KN/m2

Floor finish= 1.5 KN.m2

Brickwall load= 3.5 KN/m

Self weight of slab = 0.150 X 25 KN/m2 = 3.75 KN/m2

Total load in slab = 3.75 + 2 + 1.5 = 7.25 KN/m2

Load in each end of B1:-

Area 2(Trapezoidal area)

A1 = 1/2 * (1.529 + 4.587) * 2.5 = 7.645 m2

Bay width of B2 = A1/L or L/4

= 7.645/4.587 = 1.66 m or 1.14m

UDL transferred from slab-1 to Beam-2 = B.W X Slab-2 load

= 1.66 X 7.25 = 12.035 KN/m

Beam-1 Self weight = 0.4*0.4*25 = 4 KN/m2

Total UDL on B1 = 4 + 12.035 + 3.5 = 19.535 KN/m

Total load on B1 = (19.535 X 4.857) = 89.607 KN

Load on each end for B1 is 44.804 KN

Load in each end of B2:-

Area 2(Triangular area)

A2 = [1/2 * 2.5 * 1.529 ]* 2 = 3.82 m2

Bay width of B2 = A2/L or L/4

= 3.82/5 = 0.764 m or 1.25m

UDL transferred from slab-2 to Beam-2 = B.W X Slab-2 load

= 1.25 X 7.25 = 9.0625 KN/m

Beam-1 Self weight = 0.4*0.4*25 = 4 KN/m2

Total UDL on B2 = 4 + 9.0625 + 3.5 = 16.5625 KN/m

Total load on B2 = (16.5625 X 5) = 82.82 KN

Load on each beam B2= 41.41 KN

Total axial load on column C1 = 44.804 + 41.41 = 86.21 KN

Total axial load on C1 column = Number of floor X Load in first floor Column C1

= 15 X 86.21 = 1293.15 KN

Now we have almost got that same result from ETAB sodtware analysis= 1309.87 KN

RESULT :

• calculations for the base reactions in gravity load cases
• Submit ETABS model with the complete model of the tall building (exported .e2k format, do not attach .EDB format directly)
• The model should pass all design and serviceability requirement