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DESIGN REPORT
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Tower Crane Stability Checks
F4
F3
Tower Crane Base
60 m16.8 mLifting LoadF1 = 0
5.6 m
45.5 m
F2
Counter weight 171 KNPlease refer method statementOf Potain Tower Crane
F3 = Load due to windfor Tower CraneHeight = 45.5 m
PROJECT
DESIGN CALCULATION
CP-5
TOWER CRANE STABILITY CHECK
DESIGN BY CHECKED BY
SHAIKH
Tower Crane Mast1.6 m x3xmTotal 14 Nos ofMast use
As per manufacturers load data sheet for Tower Crane in service and out of service condition they considered 150KM/h wind speed and To Void the toppling counter weight of 72 ton at thebaseand 17.1 ton at the top is provided.(Please refer the attached load data sheet)we checked the stabilty of tower crane considering wind load and counter weight of 17.1 ton.
Load DetailsMaximum Counter weight (Concrete block) F4 = 171 KN (Please refer method statement)Maximum wind Speed considered = 150 Km/hMaximum Dynamic wind Pressure = 3.33 KN/m2 Refer the attached wind calculationTotal Height of Tower Crane = 45.5 mTower crane Windward face of area = 1.6 x45.5 mTotal Height of Counter weight Concrete block = 3 mConcrete block Windward face area = 0.65 x3 mOne Mast Windward face area = 1.6mx3.1m = 4.96 m2No of Mast install =15 NosTotal Height of Mast = 15x3.1 =46.5 m (Actual Height is 45.5) Say = 45.5Total area of Opening in one mast = 2mx 1.64 m2 = 3.28 m2Effective area for wind= 4.96 3.28 = 1.68 m2Counter weight Concrete block Height = 3 mEffective Height of tower crane for wind =45.5-3 = 42.5 mNo of Mast required for 42.5m tower crane height = 42.5/3.1 = 13.7 Say = 14Maximum Dynamic wind Pressure = 3.33 KN/m2 Refer the attached wind calculationTotal effective area of wind for tower crane height = 14x1.68 = 23.52 m2Load due to wind for tower Crane height (F3) = 3.33x23.52 = 78.33 KNMaximum Wind Load due to concrete block Height (F2) = 3.33X3X0.65 =6.5 KN
Check for OverturningTotal Restoring Moment= F4 X 16.8 = 171X16.8 =2872.8 KNmTotal Overturning MomentF3X 22.75 + F2x39.9
78.33X22.75 + 6.5X39.9 = 2042 KNmSafety factored for overturning = Total Restoring Moment /overturning Moment
= 2872.8/2042 = 1.4
1) = 45.5 m
4) = 0.18
Since Cr < 0.25 & H < 300 m , BS 6399 Apply.
5) = 41.67 m/sec
6) Calculation of Site Wind Speed (Vs) = Vb * Sa * Sd * Ss * Sp
As Per BS 6399-2 1997 From Figure 3 Cr can be interpolated
Sa = 1+ 0.001 s
Use s conservatively = 10 m
WIND LOAD CALCULATION
CP-5 Design By
Shaikh
Checked By
Dynamic Augmentation factor Cr
Basic wind speed Vb
3)
2)
PROJECT :
DESIGNCALCULATION
Effective Building height above ground level Hr
( As Per BS 6399 - 2 1997From table -1)4=Building type factor Kb
As Per BS 6399-2 1997 From Figure 3 Cr can be interpolated
WELDED STEEL UNCLAD FRAMESType of Building
Use s conservatively = 10 m
= 1.010 (Section 2.2.2.2)
Sd = 1.000 (Section 2.2.2.3)
Ss = 1.000 (Section 2.2.2.4)
Sp = 1.000 (Section 2.2.2.5)
Vs = 42.0867
Ve = Vs * Sb
As Per BS 6399-2 1997 Table -4 Factor for Sb shall be for the worst case
Sb = 2.1
Ve = 88.38
7) Calculation of Dynamic Pressure (qs) = 0.613 * Ve 2
= 4788.382
= 4.788
Calculation External Pressure co-efficient CPe
WIND X
H = 45.5 m H>B
D = 1.6 m
B = 1.6 m
N/m2
KN/m2
B
D
m/sec
m/sec
Ratio = D / H
= 0.04
WIND Z
B
H = 45.5 m H>B
D = 1.6 m
B = 1.6 m
Ratio = D / H
= 0.04
As Per BS 6399-2 1997 From Table 5 Cpe can be interpolated
WIND WARD (FRONT FACE) = 0.8 (Worst case)
LEE WARD (REAR FACE) = -0.3 (Worst case)
Calculation External Pressure co-efficient Ca From Figure - 4Area Zone = A
a (Diagonal Length) = 45.52812
D
Area Zone = Aa (Diagonal Length) = 45.52812
Ca = 0.87
External Pressures "Pe" = qs * Cpe * Ca
Wind ward Wall = 3.33
1.6
45.5
KN/m2
waquarul.shaikhLine
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waquarul.shaikhTypewritten textCounter Weight
waquarul.shaikhTypewritten textTower Crane Height
waquarul.shaikhLine
waquarul.shaikhLine
waquarul.shaikhTypewritten textCrane Height
waquarul.shaikhTypewritten textCounter weight