Project
Job No.
Part of Structure TOWER CRANE FOUNDATION Calc. by Date Chck’d by Date LG 24-10-16
Sheet no. 1
Ref.
Calculations
INDEX 1.
Introduction
2.
Reference Documents and Drawings
3.
Design Codes used
4.
Material Properties
5.
Soil bearing capacity
6.
Design methodology
7.
Design Loads
8.
Foundation Design
9.
Reinforcement sketch
10. Appendix- A :Manufacturers tower crane data sheet
App'd by
Rev. C Date
Output
Project
Job No.
Part of Structure TOWER CRANE FOUNDATION Calc. by Date Chck’d by Date LG 24-10-16
Sheet no. 2
Ref.
App'd by
Calculations
Rev. C Date
Output
1. INTRODUCTION This design report covers the structural analysis and design of foundation for tower crane to be installed. 2. REFERENCE DOCUMENTS AND DRAWINGS The following drawings and documents have been referred for establishing design forces Foundation reaction forces data sheet – for 36m high tower crane with 70m and 60m boom length. The data sheet is included in appendix -A 3. DESIGN CODES USED BS 8110- 1997
: Structural use of concrete
BS 8004- 1986
: Code of practice for foundations
BS 449 – 2005
: Steel for the reinforcement of concrete
4. MATERIAL OF PROPERTIES Concrete compressive strength at 28 days Blinding concrete
C20
: 20 Mpa
Footing
C40
: 40 Mpa
Reinforcement: steel bars of yield strength not less than 460 Mpa 5. SOIL BEARING CAPACITY 2
The allowable soil bearing capacity is taken as 210 kN/m (based on soil investigation report) 6. DESIGN METHODOLOGY The footing dimensions are estimated based on overturning moment calculations with factor of safety 1.5 Checking for sliding stability and soil bearing capacity Calculations for steel reinforcement required Checking for punching shear 7. DESIGN LOADS As per manufacturer’s data sheet, the most critical design loads are considered (crane in operations) as follows: Case 1: radius 70.00m, Hook height =43.80m Tower section= 4.14m, base tower section= 12.42m Moment, M
= 4354 kN-m
Horizontal force, H
= 85 kN
Vertical Load, V
= 902 kN
Case 2: radius 70.00m, Hook height = 52.00m, Tower section= 4.14m, base tower section= 12.42m Moment, M
= 4781 kN-m
Horizontal force, H
= 91 kN
Vertical Load, V
= 948 kN
Both cases are designed.
Project
Job No.
Part of Structure TOWER CRANE FOUNDATION Calc. by Date Chck’d by Date LG 24-10-16
Sheet no. 3
Ref.
App'd by
Calculations
Rev. C Date
Output
8. FOUNDATION DESIGN Case -1: Radius 70.00m, Hook height =43.80m
b= 1.98m, hF=1.40m, L=6.30m, h1=0.27m, h2=1.13m Vertical force Vfoundation
= 6.3 x 6.3 x 1.40 x 25
= 1389 kN
Vcrane
=
= 902 kN
Vtotal
=
= 2291 kN
Moment at base MB
= M + H x hf = 43541 +85 x 1.40
Eccentricity, e
= 4473 kN-m
= MB / Vtotal = 4473 / 2291
= 1.95 < L/3 = 6.3 /3 = 2.10 m
c= L/2 –e
= 3.15– 1.952
2 x Vtotal/ (3 L c)
= 1.198 m
Soil pressure
= 2 x2291 / (3 x 6.3 x 1.198)
2
= 202 kN/m < 215 kN/m
(/ c) (c- (L-b)/6) = (202/ 1.198) ((1.198– (6.3-1.98/6))
= 81 kN/m
2
2
Project
Job No.
Part of Structure TOWER CRANE FOUNDATION Calc. by Date Chck’d by Date LG 24-10-16
Sheet no. 4
Ref.
App'd by
Calculations
Output
= (d / 2 ) +
( x (d /3) – (hF x 25 x d /2)
d= (L-b) /2
= ( 6.30 – 1.98) /2
2
Max M1
2
2
2
= 2.16 m 2
2
= (81 x 2.16 /2 ) + (202- 81) x 2.16 /3 – (1.4 x 25 x 2.16 /2)
Max M1
= 378 kNm /m Reinforcement calculations Factored moment. Mu
= 1.50 x 378
= 567 kNm / m
Grade of concrete M40, Reinforcement Fy=460 d= 2
Mu/ bd
1400- 75 -25- 25/2
= 1388 mm
6
2
2
= 567x 10 / (1000 x 1288 )
= 0.34 N/mm per meter width
From BS 8110-3 : chart 1 100 As/ bd
= 0.09
Minimum % of steel
= 0.16
As
= 0.16 x 1000 x 1288 /100 2
= 2060 mm /m Use 25mm dia bars, spacing at 200mm c/c Area provided
=490 *1000 /200
Provide 25 dia bars at 200 mm c/c Foundation size 6.30m x 6.30m x 1.40m
Rev. C Date
2
= 2450 mm /m
Project
Job No.
Part of Structure TOWER CRANE FOUNDATION Calc. by Date Chck’d by Date LG 24-10-16
Sheet no. 5
Ref.
App'd by
Calculations
Output
Check for force at foundation anchors The largest tensile and compressive forces per foundation anchor are Max Df
= - (M/ (b sqrt(2)) – (V/4)= -(4354/ 1.98 x sqrt (2)) – (902/4) = - 1780 kN
Max. Zf
----------compressive force
= + (M/ (b sqrt(2)) – (V/4)= (4354/ 1.98 x sqrt (2)) – (902/4) = 1330 kN------------- Tensile force
Tensile force,
max Z
= Zf/ (2 . cos 30)
= 1330/ (2 x cos 30)
= 768 kN
Factored force =1.50 x 768
= 1152 kN
Using 460 grade steel, Area of steel required
= 1152 x 1000 / 460
= 2504 mm
= 2504 / 314
= 8 bars
Using dia 20 bars, Number of bars required
Rev. C Date
Provide 8 nos of dia 20 bars in both directions at each anchor location.
2
Project
Job No.
Part of Structure TOWER CRANE FOUNDATION Calc. by Date Chck’d by Date LG 24-10-16
Sheet no. 6
Ref.
App'd by
Calculations
Output
Checking for Punching shear Punching force
= 1780 kN
Factored punching force
= 1.5 x 1780 = 2670 kN
The leg is fixed using several plates welded to the main shaft . Each plate is of approximately 350mm x 350mm Punching stress under support = 2670 x 1000 / (4 *350 x 1288) = 1.48 N/mm Allowable shear stress
2
= 0.8 sqrt (fcu) = 0.8 x sqrt (40) = 5.05 N/mm
2
>> 1.48 N/mm
Rev. C Date
2
Nominal steel for punching shear is provided at each column locations. provide 10 nos of dia 16 mm bars Case -2 Radius 70.00m, Hook height = 52.00m,
b= 1.98m, hF=1.40m, L=6.50m, h1=0.27m, h2=1.13m Vertical force Vfoundation
= 6.5 x 6.5 x 1.40 x 25
= 1479 kN
Vcrane
=
= 948 kN
Project
Job No.
Part of Structure TOWER CRANE FOUNDATION Calc. by Date Chck’d by Date LG 24-10-16
Sheet no. 7
Ref.
App'd by
Calculations Vtotal
Rev. C Date
Output
=
= 2427 kN
Moment at base MB
= M + H x hf = 4781 + 91 x 1.40
Eccentricity, e
= 4908 kN-m
= MB / Vtotal = 4908 / 2427
= 2.022 < L/3 = 6.5 /3 = 2.166 m
c= L/2 –e
= 3.25– 2.022
2 x Vtotal/ (3 L c)
= 1.227 m
Soil pressure
2
= 2 x 2427 / (3 x 6.5 x 1.227)
= 203 kN/m < 215 kN/m
(/ c) (c- (L-b)/6) = (203/ 1.227) ((1.227– (6.5-1.98/6))
= (d / 2 ) +
( x (d /3) – (hF x 25 x d /2)
d= (L-b) /2
= ( 6.50 – 1.98) /2
2
Max M1
= 78kN/m
2
2
2
2
= 2.26 m 2
2
= (78 x 2.26 /2 ) + (203- 78) x 2.26 /3 – (1.4 x 25 x 2.26 /2)
Max M1
= 412 kNm /m Reinforcement calculations Factored moment. Mu
= 1.50 x 412
= 618 kNm / m
Grade of concrete M40, Reinforcement Fy=460 d=
1400- 75 -25- 25/2
= 1388 mm
2
Project
Job No.
Part of Structure TOWER CRANE FOUNDATION Calc. by Date Chck’d by Date LG 24-10-16
Sheet no. 8
Ref.
App'd by
Calculations 2
6
Mu/ bd
Output
2
2
= 618 x 10 / (1000 x 1288 )
= 0.37 N/mm per meter width
From BS 8110-3 : chart 1 100 As/ bd
= 0.10
Minimum % of steel
= 0.16
As
= 0.16 x 1000 x 1288 /100 2
= 2060 mm /m Use 25mm dia bars, spacing at 200mm c/c Area provided
=490 *1000 /200
2
= 2450 mm /m
Provide 25 dia bars at 200 mm c/c Foundation size 6.50m x 6.50m x 1.40m Check for force at foundation anchors The largest tensile and compressive forces per foundation anchor are Max Df
= - (M/ (b sqrt(2)) – (V/4)= -(4781/ 1.98 x sqrt (2)) – (948/4) = - 1945 kN
Max. Zf
----------compressive force
= + (M/ (b sqrt(2)) – (V/4)= (4781/ 1.98 x sqrt (2)) – (948/4) = 1471 kN------------- Tensile force
Tensile force,
max Z
= Zf/ (2 . cos 30)
= 1471/ (2 x cos 30)
= 849 kN
Factored force =1.50 x 849
= 1274 kN
Using 460 grade steel, Area of steel required
Rev. C Date
= 1274 x 1000 / 460
= 2770 mm
2
Project
Job No.
Part of Structure TOWER CRANE FOUNDATION Calc. by Date Chck’d by Date LG 24-10-16
Sheet no. 9
Ref.
Calculations
App'd by
Output
Using dia 20 bars, Number of bars required
= 2770 / 314
= 8.8 bars
Provide 9 nos of dia 20 bars in both directions at each anchor location.
Checking for Punching shear Punching force
= 1945 kN
Factored punching force
= 1.5 x 1945 = 2918 kN
The leg is fixed using several plates welded to the main shaft . Each plate is of approximately 350mm x 350mm Punching stress under support = 2918 x 1000 / (4 *350 x 1288) = 1.62 N/mm Allowable shear stress
2
= 0.8 sqrt (fcu) = 0.8 x sqrt (40) = 5.05 N/mm
2
>> 1.62 N/mm
2
Nominal steel for punching shear is provided at each column locations. provide 10 nos of dia 16 mm bars
Rev. C Date
Project
Job No.
Part of Structure TOWER CRANE FOUNDATION Calc. by Date Chck’d by Date LG 24-10-16
Sheet no. 10 App'd by
Ref.
Calculations
Rev. C Date
Output
9. REINFORCMENT SKETCH
Concrete: B 25 C40 Structural steel: BSt 460500 S BSt 500 M
A393 MESH
1,4 m
.See note
;z N
9
Dia 25 @ 200 c/c
--0·
�s-
-65·130-
-160-
-SO-
·50·
@
10 x 0 16 ... 5.0 m per anchor total 4 x 1 O 40 pieces
=
NOTES: FOR 43.80M HOOK HEIGHT, FOUNDATION SIZE 6.30M x 6.30M x 1.40m FOR 52.00M HOOK HEIGHT, FOUNDATION SIZE 6.50M X 6.50M x 1.40m
Ref.
Project
Job No.
Part of Structure TOWER CRANE FOUNDATION Calc. by Date Chck’d by Date LG 24-10-16
Sheet no. 11
Calculations
10. APPENDIX –A MANUFACTURERS TOWER CRANE DATA SHEET
App'd by
Rev. C Date
Output
