Project 1
AIM
Design a multi-storey Residential Building located in Bangalore using STAAD Pro Connect Edition. The specification must be as follows:
|
Building floors |
G + 6 + R |
|
Plan dimension |
B = 25m , L = 16m |
|
Storey Height |
h = 3.5m |
|
Soil |
Hard soil |
|
Use |
Residential Purpose |
|
Safe Bearing Capacity |
180 kN/m2 |
|
Maximum slab thickness |
150mm |
INTRODUCTION
STAAD.Pro is one of the popular software that is used for analyzing & designing structures like – buildings, towers, bridges, industrial, transportation and utility structures
Here we design a building using staadpro
And we design the column and beam using STAAD RCDC
The foundation is designed using STAAD Foundation
PROCEDURE
Step 1:
Given Data
|
Building floors |
G + 6 + R |
|
Plan dimension |
B = 25m , L = 16m |
|
Storey Height |
h = 3.5m |
|
Soil |
Hard soil |
|
Use |
Residential Purpose |
|
Safe Bearing Capacity |
180 kN/m2 |
|
Maximum slab thickness |
150mm |
Step 2:Creating geometry of model in staad pro
L = 16m
B = 25 m
H = 26.5 m
Size of beams = 0.300 x 0.450 m
Size of columns =0.500 x 0.500 m
Step 3:Calculation of Loads
1) Calculation of Dead Load - IS 875 part 1
Dead load on Floor
Dead load due to slab = 0.150 x 25
= 3.750 Kn/m2
Partitions = 1.5 Kn/m2
Floor Finish = 2.5 Kn/m2
Miscellaneous = 1 Kn/m2
Total Floor Load = 8.75 Kn/m2
Dead load on Roof
Dead load of Roof Slab = 3.75 Kn/m2
Insulaions and WaterProofing = 0.5 Kn/m2
MEP Services = 0.5 Kn/m2
Miscellaneous = 0.5 Kn/m2
Total Roof Load = 5.25 kn/m2
2) Live Load - IS 875 part 2
For Residential Building LL = 3 Kn/m2
For Roof = 1.5 Kn/m2
3) Calculation of Wind load
Design Wind Speed
We know that
Vz = Vb x k1 x k2 x k3 x k4
where ,
Vb=Basic wind speed (m/sec)
K1=Risk coefficient (Table 1 of IS 875 (Part 3)-2015)
K2 = Terrain Roughness and height factor
K3=Topography factor (Clause 6.3.3 of IS 875 (Part 3)-2015)
K4 =Importance factor for Cyclic Region
AS Vb = 33 m/s ( Darjeeling ) Is 875
K1 = 1
K2 = 1.13( Category 1)
K3 = 1
K4 = 1
Therefore ,
Vz = 33 x 1 x 1.13 x 1 x 1
= 37.29 m/s
- ii) Wind Pressure = Pz
Pz = 0.6 x Vz ^2
= 0.6 x 37.95 x 37.95
= 864.121 N
= 0.834 Kn
Similarly we can calculate for different heights
|
Height (m) |
k2 |
Vz (m/s) |
Pz |
Pz in kN |
|
4 |
1.05 |
34.65 |
720.37 |
0.720 |
|
7.5 |
1.05 |
34.65 |
720.37 |
0.720 |
|
11 |
1.06 |
35.2 |
743.424 |
0.743 |
|
14.5 |
1.08 |
35.64 |
762.12 |
0.762 |
|
18 |
1.10 |
36.3 |
790.61 |
0.790 |
|
21.5 |
1.125 |
37.13 |
827.18 |
0.827 |
|
25 |
1.13 |
37.29 |
834.32 |
0.834 |
|
26.5 |
1.13 |
37.29 |
864.121 |
0.834 |
4) Calculation of Seismic load
1) Design Base Shear
VB = Ah x W
where ,
Ah = Horizontal Coefficient of acceleration
W = Seismic Weight
ii) Ah can be calculated by using formula
Ah = Z/2 x Sa/g x I/R
As given building in location is in Bangalore -
- a) Seismic Zone (Z) - Zone II ( 0.10 )
- b) Soil condition or Soil type (Sa) - Hard Soil
- c) Importance Factor - 1 ( For Residential Building )
- d) Response Reduction Factor - 5 ( SMRF)
2)
i) Now we have to calculate the Sa/g ( Spctral Acceleraion cpefficient) which depends on Type of soil .
ii) For hard Soil -
Sa/g = 1 + 15 T .........................0.00 < T < 0.10
2.50 ...............................0.10 < T < 0.40
1 / T ..............................0.40 < T < 4.00
iii) First we have to calculate time peroiod in x and y direction
Tx = `(0.09h)/sqrt d`
= `(0.09X26.5 )/4`
Tx = 0.68 sec
Ty = `(0.09h)/sqrt d`
= `(0.09X26.5 )/5`
Ty = 0.54 sec
Considered Max time period i.e Tx = 0.68 sec
Therefore
Sa / g = 1/T
= 1.47
So put all the values in Ah equation
Ah = 0.10/2 x 1.47 x 1/5
Ah = 0.0147
3) Calculation of Seismic weight
i) Area of each Floor = 16 x 25
= 400 m^2
ii) Due to Dead Loads , Typical Floor = DL = 8.75 Kn/m^2
So Total Dead load of all floors = 8.75 x 400
= 3500 Kn
iii) Due to Dead Loads ,Roof = DL of roofs = 5.25 Kn/m^2
So Total Dead load of all floors = 5.25 x 400
= 2100 Kn
iv) Due to Live Loads , Typical Floor = LL = 3 Kn/m^2 ( Is 875 part 2)
But as per IS 1893:2016 If Live load is greater than 3 Kn/m^2 we have to reduced LL by 50%
Therefore reduced it by 50%
LL = 1.5 Kn/m^2
Total Live load for all floors = 1.5 x 600
= 600 KN
v) Due to Live Loads , Roof - AS per IS 1893 : 2016 Live load due to roof is neglected in calculation of seismic weight .
vi) Total Seismic Weight = W = DL + LL + DL roof
= (3500+ 600) x 7 + 2100
= 30800 Kn
4) Design Base Shear VB
VB = Ah x W
= 0.0147 x 30800
= 452.76 Kn
|
Storey level |
Wi |
hi |
Wihi2 |
ki |
Lateral Force |
|
|
(kN) |
(m) |
Qx |
Qz |
|||
|
Roof |
2100 |
26.5 |
1474725 |
0.1654 |
74.886 |
74.886 |
|
6th |
4100 |
25 |
2562500 |
0.2874 |
130.1232 |
130.1232 |
|
5th |
4100 |
21.5 |
1895225 |
0.21258 |
96.2477 |
96.2477 |
|
4th |
4100 |
18 |
1328400 |
0.149 |
67.46 |
67.46 |
|
3rd |
4100 |
14.5 |
862025 |
0.09669 |
43.77 |
43.77 |
|
2nd |
4100 |
11 |
496100 |
0.0556 |
25.1734 |
25.1734 |
|
1st |
4100 |
7.5 |
230625 |
0.0258 |
11.68 |
11.68 |
|
GF |
4100 |
4 |
65600 |
0.0056 |
2.535 |
2.535 |
|
∑ |
8915200 |
1 |
451.86 |
451.86 |
||
The Dead load,Live load,Wind load,Sesmic load is calculated and the values are added to the staad model
Also add load combinations
Design of slab element
Span Shorter Direction (Clear) ly = 5 m
Span Longer Direction (Clear) lx = 4 m
Live Load on the Slab LL = 3 kN / m2
Compressive stength of concrete fck = 25 N / mm2
Yield strength of steel fy = 415 N / mm2
Unit weight of concrete Ƴc = 25.00 kN / m3
Unit weight of floor finish 100 mm Ƴ = 22.00 kN / m3
Clear concrete cover = 25.00 mm
Bearing of slab B = 250.00 mm
Step 1
Span to effective depth ratio l/d = 32
Minimum effective depth d = 125 mm
Overall depth D = 150 mm
Provide Overall depth D = 150 mm
Dia of bars for short direction Φ = 12 mm
Dia of bars for long direction Φ = 12 mm
Effective Depth d = 120 mm
Loading on the slab
Dead Load of the slab (DL) =3.75 kN / m2
Super Dead Load =5 kN / m2
Live Load on the slab =3 kN / m2
Total Load on the slab (TL) =11.75 kN / m2
Design Load = (Total Load x Load Factor i.e. 1.5) =18 kN / m2
Effective Span lx = 4.12 m
ly = 5.12 m
Ratio ly/lx = 1.2 Two Way
1.0 ax 1.10 ay
For negative moments (at top) 0.047 0.047 0.053 0.047
For positive moments (at bottom) 0.035 0.035 0.04 0.035
Step 2 BM per unit width of slab
Mx = ax w lx2 My = ay w lx2
For negative moments (at top) 18.33 13.75 KN-m/m
For positive moments (at bottom) 14.36 10.69 KN-m/m
Shear force , V 0.5wlx 37.08 kN/m
Step 3 To check the effective depth of slab
Mu,lim = 0.138fckbd2
d = 72.83 mm
Step 4 Depth of slab for shear force
τc,max = 4 N/mm2
τc = 0.3
k = 1.2
D=220mm
τc = 0.36 N/mm2
τv = Vu / bd = 0.28 N/mm2
τv < τc < τc,max
0.3 0.36 .46
Hence SAFE
Step 5 Determination of areas of steel
Mu = 0.87fyAstd(1-Astfy/fckbd)
For Negative moments
Mu Top = 22.60
Ast = 463.99 mm2/m
For Positive moments
Mu Bot = 16.83
Ast = 345.52 mm2/m
Step 6 Determination of distribution steel
Astmin = 0.12bd
=144 mm2
Step 7 Selection of reinforcing bars
Area of bars (Top steel) = 302 mm2
Spacing = 374 = 300 mm
Provide 12mm bars at a spacing 300mm
Area of bars (Bottom steel) = 236 mm2
Spacing = 327 = 300 mm
Provide 12mm bars at a spacing 300mm
Design beam and element using STAAD RCDC
Step 1:complete the model after analysis click on Advanced concrete design
Input the needed details
Step 2:Click on design tab and check all data given
Make changes if needed
Step 3:Check whether any beam failed or not.
Step 4:click on Design
Click on report and select Design calculation report
Step 5:Click on BBS
And Gererate BBS
Design column and element using STAAD RCDC
Step 1:complete the model after analysis click on Advanced concrete design
Input the needed details
Step 2:Click on design tab and check all data given
Make changes if needed
Step 3:Check whether any beam failed or not.
Step 4:click on Design
Click on report and select Design calculation report
Select a column for report
Step 5:Click on BBS
And Gererate BBS
Select a column
Design Foundations using STAAD Foundation
Step 1:complete the model after analysis click on Foundation design
Input the needed details
Step 2:Create new job
Input the needed details
Step 3:Click on Design
RESULTS
i) DBR is prepared
ii) Structural Model has been created and Analyze it successfully
iii) DL, LL, WL and EQL load are calculated in above steps as per IS 875 standards
iv) Slab element is designed and calculated
v) Beam and Column is designed in RCDC and Design Calculation report is ptovided
vi) BBS is prepared
vii) Foundation is designed using Staad Foundation .