Project 1_Comparative study of different storey buildings for Seismic forces
Effect of mass on T: Compare fundamenl of natural periods of buildings H, J and K.have the buildings become more flexible or stiff due to change in mass?
AIM - To Compare fundamental natural periods of buildings H, j and K. using ETA8S
Procedure:
Building H
Step 1
1) Click the Define tab and click section properties
2) Select Add new property and choose Rectangular
3) Add the new column dimension of 800 x 800
4| click Ok
Step 2:
1) Click the Select tab and select the columns
2) CIiCk assign tab and choose frame assignment as 800 x 800 dimension column
3) Click ok
Step 3
1) After assigning laads of each frame run the anaiysis
2) Click Display and choose the show table option
3) Select modal participating ratio from Structural output
4) click ok
Building j
Step 1
1) Click the Edit tab and choose edit story
2) Add 25 story and make 1st story as Master and all other as similar to 1st story
3) Click ok
Step 2:
1) Click the Select tab and select the columns
7) click assign tab and choose frame assignment as 800 x 800 dimension column
3) Click ok
Step 3:
1) Ctck the select tab and assign the column dimensions as 800 x 800
2) Click the Select tab and choose floors
3) Click assign tab and choose shell loads then uniform load
4) Make live load and load pattern name and input 3Okn/sq.m for load value
5) Click Ok
Step 4:
1) Click the Select tab and choose beams
2) Click assign tab and choose frame loads them distribute
3) Make brick: wall laad as input 1OKn/sq.m for load vale
4) Cock OK
Step 5.
1) After assigning loads of each frame run the analysis
2) Click display and choose the show table
option
3) Select Modal participating ratio from Structural output
4) click ok
Building K
Step 1:
1) Click the select tab and assign the column dimensions as 800 x 800
2)Click the Select tab and choose floors
3) Click assign tab and choose shell loads then uniform load
4) Make a live load and load pattern name and input 6Okn/sq.m for load value
5) Click Ok
Step 2.-
1) After assigning loads of each frame run the analysis
2)Click Display and choose the show table option
3) Select Moadal participating rat‹o from Structural output
4) click ok
Conclusion -
1) For building H,j,k are the same 25 story but the load increases gradually like 10% and 2O% because of this the building becomes more Flexi due to an increase in weight.
2)time period of H is 3.0 j is 3.411 and k is 4.036.
Comparison 2:
Building A
Step 1:
1) Ctick the Edit tab ard choose edit story
2) Add 2 story and make 1st story as Water and all other as similar to 1st story
3)Click ok
Step 2
1)Click the select tab and select the columns
2) Click assign tab and choose frame assignment as 400 x 400 dimension column
3) Click ok
Step 3:
1) After assigning loads of each frame run the analysis
2) Click Display and choose the show table option
3) Select modal participating ratio from Structural output
4) click ok
Building B:
Step 1:
1) Click the Edit tab and choose edit story
2) Add 5 story and make 1st story as Master and all other as similar to 1st story
3) Click ok
Step 2:
1)Click be select tab and select the columns
2)Click assign tab and choose Name assignment as 400 x 4OO dimension column
3)Click ok
Step 3:
1) Click the select tab and assign the column dimensions as 400 x 400
2) Click the Select tab and choose floors
3) Click assign tab and choose shell loads then uniform load
4) Make live load and load pattern name and input 3 kn/sq.m for load value and brickwall load as 10 kn/sq.m
5) Click OK
Step 4:
1) After assigning loads of each frame run the analysis
2) Click Display and choose the show table option
3) Select Modal participating ratio from Structural output
4) click ok
Building F:
Step 1
1) Click the Select tab and select the columns
2} Click assign tab and choose frame assignment as 600 x 600 dimension column
3) Click ok
Step 2:
1) After signing the loads of each frame run the analysis
2) Click display and choose show table option
3] Select modal participating ratio from Structural output
4) click ok
Conclusion -
1) Due to the changing of building height the fundamental natural pefiod varies gradually i.e. for A is 89% at 0.39 for B is 83% at 0.911, for F is 75% at 0.48 and finally for H is 78% is
3.811.
Step 1:
1)Click be Select tab and select the columns
2)Click assign tab and choose frame assignment as 55O x 3OO dimension column
3)Click ok
Step 2.-
1) Select the colamn object
2) Click the Assign tab and choase frame section s then local axes
3) Select rotation angle and enter the degree ot 180
4) Click Ok
Step 3:
1) After assigning loads of each frame run the analysis
2 Click Display and choose show table option
3) Select modal participating ratio from Structural output
4) click ok
Building D
STEP 1:
1)Click the select tab and select the commas
2)Click assign tab and choose frame assignment as 300 x 55O dimension column
3)Click oK
Step 2:
1) Select the column o6ject
2)Click the Assign tab and choose frame sections then tocat axes
3) Select rotation angle and enter the degree of 90
4) Click Ok
Step 3-
1) After assigning loads of each frame run the analysis
2) Click display and choose the show table option
3) Select modal parficipating ratio from Structural output
4) click ok
Conclusion-
1) Due to changing of orientation the fundamental of the natural period varies each building i.e. for C is 0.91 and for D is 1.04 then for B is 0.941
Comparison 4
For Building E
Step 1-
1) click the Edit tab and choose edit story
2) Add 10 story and make 1st story as master and all other as similar to 1st story
3) Click ok
Step 2:
1) After assigning loads of each frame run the analysis
2)Click Display and choose the show table option
3) select modal participating ratio from Structural output
4) click ok
Building G:
Step1:
1) Click the Edit tab and choose edit story
2) Add 25 story and make 1st story. 11th story and 21st story as Master and all other a similar to 1st, 11th, 21st story
3] Click ok
Step 2:
1) Click be edit tab and select the columns of the 11th story ( make sure story selection must
be in similar story mode)
2) Click assign tab and choose frame assignment as 600 x 600 dimension column
3l Click ok
Step 3:
1) Click the select tab and select the columns of 1st story I make sure story selection must be in
similar story mode)
2] Click assign tab md choose frame assignment as 400 x 400 dimension column
3) Click ok
Step 4
1) Dck Select tab and select the columns
2) Click cssign tab cmd choose fmme assignment as 400 x 4OO dimensi column
3) Click ok
Step 5
1) After assigning loads of each frame run the analysis
2) Click Display and choose the show table option
3) Select modal partcipating ratio from Structural output
4) cick ok
Conclusion -1)
When comparing these building there is significant difference due to different column sizes. The fundamental period of building Eis 0.36 and for Fis 0.48. similarly for building G is 3.85 and for building His 3.01