Projefct 1_Comparative study of different storey buildings for Seismic forces
Aim and introduction:
Project 1 – Factors influencing the Natural Period of a building
Structural Element Sizes
- Beams : 300 × 400 mm
- Columns : 400 × 400 mm
- Slab : 150 mm thick
Material Properties
- Grade of Concrete : M30
- Grade of Steel Reinforcement Bars : Fe 415
Loading
- Dead Load on beams from infill wall : 10 kN/m
- Live load on floor : 3 kN/m2
(what is the seismic mass?)
Buildings are assumed to be pinned at base
Five-storey Benchmark Building: Elevation and plan of benchmark building showing the structural moment frame grid (All dimensions are in mm)
Project 1 – Factors influencing the Natural Period of a building
Buildings considered to illustrate concept of natural period: Details of 10 buildings considered
Similarly we can analyse the remaining models
- Model B
- Model C
- Model D
- Model E
- Model F
- Model G
- Model H
- Model J
- By incresing 10% of imposed mass
- Model K
- By increasing 20% imposed mass
Model A
Model B
Model C
Model D
Model E
Model F
Model G
Model H
Model J
Model K
Results:
- By comparing the E and F the natural time period is similar
In the G and H Due to the more storeys the Similarity is going higher compare to the E and F
These are similar thats why they have marginal difference.Due to using different type of columns its varied
- By Comparing H ,J and K
There is no change in flexibility and stiffness by varying a mass in the model
- By comparing the height A,B,F and H
With the increase in height the natural time period also increases.
- By comparing the column orientation in B,C and D
Changing the orientation of the column The time period is more in horizontal alignment of column in C
In B the arrangement of columns is equal 0.537
In C the arrangemnt of columns in X direction is more 0.549
In D the arrangement of columns in vertical manner 0.542