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