Project 1
AIM : To design a Main Frame with Lean (Grid 2) & Gable Frame without Lean (Grid 15) of proposed coil center with the given data
PROCEDURE:
- From the attached CAD file, proposed coil center sectional view is as shown in below figure.
- According to the given data , draw the plan in the staad pro as shown below
- Adding load cases to the above plan of modelled frame
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Calculation of Dead load on rafter & column= 0.14 kN/`m^2`
= 0.14x10 =1.4 kN/m
Purlin Load = 8.77kg/m = 87.7 N/m
= 87.7x10 N = 877 N
= 0.877 kN
Assuming weight of sag rod, Bracings, Clips etc. =5.75 kg/m2=0.0575x10=0.575 kN/m
Assume Weight of Roof Sheeting (0.55 mm Galvanized sheet) = 5 kg/`m^2`
= 0.05x10 =0.5 kN/m
Total Dead Load = 1.4+0.5+ 0.575 = 2.475 kN/m
Total Live Load = 0.75 kN/`m^2`x 10 = 7.5 kN/m
Collateral Load = 0.15 kN/`m^2` x 10 = 1.5 kN/m
Total Dead Load on Lean = 2.475/2+ 1.5 kN/m = 2.736 kN/m
Live Load on Lean = 3.75 kN/m ( since bay spacing=5 m)
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Now Applying Seismic Load Calculation:
Seismic definition then defining Seismic parameters as follows-
- Select IS 1893-2002/2005
- For Chennai , zone factor (Z) = 0.16 for zone-3
- Response Reduction factor = 5 for SMRF ;
- Importance factor =1 (For general Building) ;
- Soil type =2 (Cosidering soil as medium soil)
- Structure type =1 ; Damping Ratio =0.05
- Click on Generate Button, all parameters are available as shown in below figure
- Now to see the loads applied click on the specific loads and the blue coloured loads indicate the load selected.
- Apply all the loads created on the specific portions of the modelled frame
- After the calculation of dead and live loads for the above frame we are also given crane load.
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Calculation of Crane Load:
CRANE LOAD- (GIVEN DATA) :
Crane capacity : 30 MT ( EOT Creane)
c/c of crane rail : 27.41 m
Crane height : 7.5 m
Crane wt including hoist : 35 MT
Gantary Girder wt : 158.24 kg/m
Rail wt : 53 kg/m
No of Wheels : 4
Wheel Base : 5.8 m
Bumper Distance : 6.2 m
Maximum wheel Load : 262.00 kN
Vertical impact : 25% As per IS 875
Lateral impact : 20% As per IS 875
Longitudinal impact : 10% As per IS 875
Max. wheel load ( Vertical) = [ 35/2 + 30]/2 =23.75 MT = 237.5 kN
Dead load of Rail and Gantry Girder = (158.24 + 53 )kg/m =211.24 kg/m
= 2.11 kN/m = 2.112x10 = 21.12 kN
Vertical load on each Handle = 10.56 kN
Max Reaction on Crane Handle `R_max` with Dead load of Rail & Gantry girder`
= 237.5+ 10.56 = 248.06 kN
Min. Reaction on the Handle `R_min`= 0.4x 248.06= 99 kN
Horizontal wheel load transverse to rails = 0.2x30/2 = 3 MT = 30 kN
Max Reaction on the Handle with Impact of 25% as per IS 875/ Part-2,clause 6.3 :
`R_max` = 1.25x 248.06 kN = 310.075 kN
Design vertical load with F.S = 310.075x 1.5 = 465 kN
`R_min`= 99 kN
Total cases possible for the above loading can be seen below :
Application of load for various cases can be seen in the below figures :
- CASE 1 :
`R_max` on left Handle , +H on Left Handle , `R_min`on Right Handle
- CASE 2 :
`R_max` on left Handle , -H on Left , `R_min`on Right Handle
- CASE 3 :
`R_min` on left Handle, +H on Right Handle , `R_max`on Right Handle
- CASE 4 :
`R_min` on left Handle, -H on Right Handle , `R_max`on Right Handle
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Horizontal traction force along the rails = 0.1 (262.5+262.5) = 52.5 kN
( 10% as per given input but as per IS 875 part-2 Clause 6.3.2 it is 5%)
CALCULATION OF WIND PRESSURE:-
Basic wind speed`V_b`=180 kmph = 50 m/s
`K_1`= 1.0 ( General Bldg as per Table-1 of IS:875,Part-3)
`K_2`=0.94 ( For Terrain category 3)
`K_3`= 1.00( Upwind slope is less than 3 degree)
`K_4`=1.15 ( IS 875 Cyclone Zone)
Design wind speed `V_z`= `K_1xxK_2xxK_3xxK_4xxV_b`
= 1x0.94x1.0x1.15x50 = 51.75 m/s
Wind Pressure `P_z`= 0.6x `V_z^2` = 1606.84 N/`m^2` = 1.61 kN/`m^2`
Design wnd pressure `P_d= K_d xxK_axxK_c xxP_z`
`K_d`=0.9 ( Directionality factor)
`K_a`= 0.9 ( Area averaging factor)
`K_c`= 0.9 (Roof is subjected to pressure & suction)
`P_d`= 0.9x0.9x0.9x 1.61 = 1.17 KN/sq`
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WIND LOAD CASE-1 : Wind across the Ride ( 0 degree) with +v e `C_(p i)`
Roof angle `alpha = 5.71^0`
Surface `C_(pe)` `C_(p i)` `C_p=( C_(pe-C_(p i) ))` wind load on frame`F = C_pxxAxxP_d` A 0.7 0.5 0.2 1.17 EF -0.94 0.5 -1.44 -16.85 GH -0.4 0.5 -0.9 -10.53 B -0.25 0.5 -0.75 -8.78 C -0.6 0.5 -1.1 -3.2175 D -0.6 0.5 -1.1 -22.5225 0.41 0.5 -0.09 -0.5 Lean to 0.41 0.5 -0.09 -0.5
- Load case-1
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WIND LOAD CASE-2 : wind across the Ride ( 0 degree) with -v e `C_(p i)`
Roof angle `alpha = 5.71^0`
Surface `C_(pe)` `C_(p i)` `C_p=( C_(pe-C_(p i) ))` wind load on frame`F = C_pxxAxxP_d` A 0.7 -0.5 1.2 7.02 EF -0.94 -0.5 -0.44 -5.15 GH -0.4 -0.5 0.1 -1.17 B -0.25 -0.5 0.25 2.93 C -0.6 -0.5 -0.1 -0.2925 D -0.6 -0.5 -0.1 -2.0475 Lean to 0.41 -0.5 0.91 5.32 Extended roof 0.41 -0.5 0.91 5.32 Load case-2
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WIND LOAD CASE-3 : wind parallel the Ride ( 90 degree) with +v e `C_(p i)`
Roof angle `alpha = 5.71^0`
Surface `C_(pe)` `C_(p i)` `C_p=( C_(pe-C_(p i) ))` wind load on frame`F = C_pxxAxxP_d` A -0.5 0.5 -1.0 -5.85 EF -0.8 0.5 -1.3 -15.21 GH -0.8 0.5 -1.3 -15.21 B -0.5 0.5 -1.0 -11.7 C -0.7 0.5 -1.1 -3.2175 D -0.1 0.5 -1.1 -22.5225 Lean to 0.41 0.5 -0.09 -0.5 Extended roof 0.41 0.5 -0.09 -0.5 Load case-3
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WIND LOAD CASE-4 : wind parallel the Ride ( 90 degree) with -v e `C_(p i)`
Roof angle `alpha = 5.71^0`
Surface `C_(pe)` `C_(p i)` `C_p=( C_(pe-C_(p i) ))` wind load on frame`F = C_pxxAxxP_d` A -0.5 -0.5 0.0 0.0 EF -0.8 -0.5 -0.3 -0.36 GH -0.8 -0.5 -0.3 -0.36 B -0.5 -0.5 0.0 0.0 C -0.7 -0.5 -1.1 -3.275 D -0.1 -0.5 -1.1 -22.5225 Lean to 0.41 -0.5 0.91 5.32 Extended roof 0.41 -0.5 0.91 5.32 Load case-4
- Now run the analysis to check for errors, if no errors then the Structure has been succesfully designed.
- Run Analysis until there are zero errors,these can be seen from the images shown below.
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Gable frame is also analysed with load intensity 50% (Dead load,live load and wind load only) of Main frame
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Wind load in Z direction due to gable frame is as shown in the below figure.
- We have runned the analysis for the Gable Frame also with Zero Errors which can be seen from the image attached below.
Result:
Model has been successfully modelled in the STAAD Pro, for the given data. Analysis has been performed successfully with zero errors.