Cooling Tank Support Structure

7/21/2019 Cooling Tank Support Structure

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Rev3

Client: Al Ain Wildlife Park & Resort

Analysis & Design of Cooling Tower Support Structure .

Cooling tower-1

1 . IntroductionStructure description :

Support Structure for Back Cooling Units

The steel columns are fixed on the floor at bottom with mechanical anchor bolts

The platform top structure joints are all welded

The column are of size UB 254X146X37

main and secondary beams are UB 254X146X31

The purpose of following calculations is as listed below;

(A) To check the proposed steel supporting structure .

(B) To check the structural stability of the platform structure for all incident loads on it.

(C) To check & design proposed economical and most practical member sizes of the

supporting structure of the platform such as top beam section, support channel

from stability point of view.

(D) To check proposed anchoring arrangement for support fixing to the building structure...

Reference Documents and Design Parameters ::

1) drg.Sheikh Zayed Desert Learning Center -

AWPR-SZC-CAP-SCD-SZC-ARC-DWG-00322-00

3) All structural steel members conform to ASTM A36 / BS grade S275 steel or equivalent

4) All connection bolts conform to BS grade 8.8 or equivalent and galvanised .

mechanical anchors shall be used.

5) Concrete strength on which supports are to be fixed is assumed C30/37 ( 30/37 N/mm2 )

6) Allowable deflections : Beams L/250 cantilever L/180

Design codes::

Design of platform steel structure has been done conforming to following codes of practice.

* BS 5950 - Part 1:2000 -Structural use of steelwork in building.

* BS 8110 -1:1997 ,BS 8110-3:1985 -Structural use of concrete

* BS 6399-1, 2 :1997 for Loading

16.07.2011LINK MIDDLE EAST LIMITEDP.O. Box 16846, Dubai – U.A.E.Tel No. +971 4 8816750, Fax No. +971 4816250

231796382.xls.ms_office



Analysis and Design

Analysis and Design of the platform structure has been done using

STAAD Pro 2006 Analysis and Design software.

The supporting structure has been analysed for given loadings and members are

designed by STAAD Pro programme. Othet minor members have been designed manually.

For Staad design of steel members British Code BS5950-1:2000 has been used.

2 .STAAD model and Loads

Staad model:

3D view:

The structure is modeled as Space frame , with fixed suported on floor slab

Loads :

1) Dead load ( DL)




self weight of supporting steel structure is calculated by STAAD programme.

consider N100/30 serrated grating with 3 mm load bars at 30 mm c/c, self wt = 100 kg/m²

Grating is welded to the top skeleton of the platform. = 1 kN/m²

Equipment load is given as 3.92 ton = 39.2 kN UDL = 39.2 / area = 10 / (2.3x7.47) = 2.28 kN/m²

consider 50% impact due to machine = 2.28 x 1.5 = 3.42 kN/m²

Hence total dead load = 1 + 3.42 = 4.42 kN/m²

Load is applied as floor load command in staad.

5% of above load is considered acting in horizontal direction X and Z = 0.05x4.42 = 0.23 kN/m²

This applied as horizontal UDL on main beams

2) Live load ( LL)

consider live load = 7.5 kN/m² as per BS6399 code for equipment platform..


5% of above load is considered acting in horizontal direction X and Z = 0.075x5 = 0.375 kN/m²


3) Wind load (WL)

Basic wind speed Vb = 26 m/s

Site wind speed Vs = Sa.Sb.Ss.Sd.Vb cl. 2.2.2.1 of BS6399-2:1997

= 1x1x1x1x26 all factors considered 1.0 to be conservative

= 26 m/s




dynamic pressure q = 0.613 x Ve2

Ve = effective wind speed

= Vb.Sb

for site in town terrain , ( cl.3.2.3.2.3 )

Sb = Sc.Tc.{ 1+(gt.St.Tt) + Sh }

Sc : fetch factor 1.67 .. from table 22 by interpolation

St : turbulance factor 0.0884 .. from table 22 by interpolation

Tc ; fetch adjustment factor 0.954 .. from table 23 by interpolation

Tt : turbulance adjustment factor 1.08 .. from table 23 by interpolation

gt : gust peak factor 3.44 .. from table 24 by interpolation

Sh : topographic increment 0 .. from cl. 3.2.3.4.1 not significant

Sb = 1.67 x 0.954 { 1 +(3.44 x 0.0884 x 1.08) + 0} = 2.11

Ve = 2.11 x 26 = 54.86 m/s


= 0.613 x 54.862

= 1.84 kN/m2

wind load factor Cp= 1.2

wind load =Cp x dynamic wind pressure x projected area

= Cp . q. projected area of member

for diagonal member WL = 1.2 x 1.84 x 0.08 = 0.17 kN/m

All these loads have been applied in Staad as horizontal loads.

for vertical support member WL=1.2 x 1.84 x0.25 =0.56

for horizontal support member WL=1.2 x 1.84 x0.20 =0.44




Wind in X dir & Z directions are considered separately.

i.e WL-x & WL-z

4) Load combinations:

\ Load combinations will be as follows;

(a) Service load combination :: ( for deflections)

1.0 DL+1.0 LL

1.0DL+1.0LL+1.0WL

(b) Design load combination :: ( for design of steel members,design of connections etc.)

1.4 DL+1.6 LL

1.0DL+1.4WL

1.2DL+1.2LL+1.2WL

3 . Analysis and design of Steel Structure.

Analysis and design has been done by STAAD Pro 2006 analysis and design software.

Refer Staad output:

All members are structurally safe.

4. Design of Connections

Following major connections are designed based on the forces in the connecting members.

and as per Staad Pro computer output.

* Anchor bolt Connection between column bases & concrete floor

4.1 Anchor bolt Connection between columns & concrete floor .

UB 254X146X37 is fixed to the concrete floor with M20 mechanical anchors.

1.0DL+1.0WL




Fx = 7.5 kN

Fy = 100 kN

Fz = 8.56 kN

Mz = 9.1 kNm

Use 420x320x20 thk base plate for columns.220

50

420x320X20 thk

120 base plate

It is proposed to use 4 no. M20 mechanical anchor bolts

Actual tension in bolt = 7.5/4 = 1.88 kN

Actual shear in bolt = 100/4 = 25 kN

tensile capacity of M20 bolt = 110 kN > actual tension( 1.88 kN)

shear capacity of M20 bolt = 91.9 kN > actual shear ( 25 kN)

End plate :

max moment in end plate = 2 x 1.88 x 0.05 = 0.18 kNm

Moment capacity of end plate per unit width = py.tp²/4 ..cl.6.3.4.3, BS5950-1:2000

\Moment capacity of end plate = py.b.tp²/4 = 275 x 320 x 20² /4 = 8.80 kNm > actual moment in end plate

hence safe

Hence provided 4 no. M20 mechanical anchor bolts and the end plate are safe.

4.2 Angle Connection between UC 254x146x31mm to UC 254x146x31mm .

Fx = 22.8 kN

Fy = 58 kN

Fz = 7.22 kN

Mz = 15 kNm

use 200x180x12mm thk connecting plate




It is proposed to use 4 no. M16 HILTI/Equivalent anchor bolts

Max tension in bolt = Fx / 4 = 22.8 /4 = 5.7 kN

Max shear in bolt = Fy / 4 = 58 /4 = 14.5 kN

.

tensile capacity of M16 bolt = 70.3 kN > actual tension

shear capacity of M16 bolt = 58.9 kN > actual shear

End plate :

max moment in end plate = 22.8x 0.05 = 1.14kNm

Moment capacity of end plate per unit width = py.tp²/4 ..cl.6.3.4.3, BS5950-1:2000

\Moment capacity of end plate = py.b.tp²/4

= 275 x180 x 12² /4 = 1.78 kNm > actual moment in end plate

hence safe

Hence provided 4no. M16 HILTI HEX bolts/equivalent and the end plate are safe.

5 . Deflection check.

Refer Staad output. Deflection diagram.

Max deflection = 3.2 mm < 8.92 mm ( span /250 ,,2230/250 )

.. Hence safe

6. Conclusion :

** The proposed platform & the support structure and its members are safe for

given revised Live loads in combination with other loads.

** The proposed connections are structurally safe.

** The proposed anchors are structurally safe.

Utilization Ratio




Rev3

Client: Al Ain Wildlife Park & Resort Analysis & Design of Cooling Tower Support Structure .

Cooling tower-2

1 . Introduction

Structure description :

Support Structure for Back Cooling Units near stair area








(C) To check & design proposed economical and most practical member sizes of thesupporting structure of the platform such as top beam section, support channel












5) Concrete strength on which supports are to be fixed is assumed C40 ( 40 N/mm2 )


Design codes::




* BS 6399-1, 2 :1997 for Loading

Analysis and Design







Staad model:



3D view:


Loads :

1) Dead load ( DL)




Equipment load is given as 3.92 ton = 39.2 k UDL = 39.2 / area = 10 / (2.3x7.47) = 2.28 kN/m²






2) Live load ( LL)







3) Wind load (WL)




= 26 m/s



= Vb.Sb








Sh : topographic increment 0 .. from cl. 3.2.3.4 not significant

Sb = 1.67 x 0.954 { 1 +(3.44 x 0.0884 x 1.08) + 0} = 2.11

Ve = 2.11 x 26 = 54.86 m/s




= 0.613 x 54.862

= 1.84 kN/m2







i.e WL-x & WL-z




1.0 DL+1.0 LL

1.0DL+1.0LL+1.0WL


1.4 DL+1.6 LL

1.0DL+1.4WL

1.2DL+1.2LL+1.2WL



1.0DL+1.0WL





Refer Staad output:








Fx = 46 kN

Fy = 108 kN

Fz = 33.5 kN

Mz = 15.25 kNm

Use 420x320x20 thk base plate for columns.220

50

420x320X20 thk

120 base plate


Actual tension in bolt = 46/4 = 11.5 kN

Actual shear in bolt = 108/4 = 27 kN



tensile capacity of M20 bolt = 110 kN > actual tension( 11.5kN)

shear capacity of M20 bolt = 91.9 kN > actual shear ( 27 kN)

End plate : ..cl.6.3.4.3, BS5950-1:2000


Moment capacity of end plate per unit width = py.tp²/4


= 275 x 320 x 20² /4 = 8.80 kNm > actual moment in end plate

hence safe



Fx = 26.5 kN

Fy = 56.33 kN

Fz =12 kN

Mz = 42.67 kNm



Max tension in bolt = Fx / 4 = 26.5 /4 = 6.63 kN

Max shear in bolt = Fy / 4 = 56.33/4 = 14.08 kN

.

tensile capacity of M16 bolt = 70.3 > actual tension

shear capacity of M16 bolt = 58.9 > actual shear

End plate : ..cl.6.3.4.3, BS5950-1:2000max moment in end plate = 26.5x 0.05 = 1.32kNm




hence safe




Max deflection = 4mm < 8.92 mm ( span /250 ,,2230/250 )

.. Hence safe

6. Conclusion :







Utilization Ratio



Rev3



Cooling tower-3

1 . Introduction


Support Structure for Back Cooling Units near stair area
















4) All connection bolts conform to BS grade 8.8 or equivalent and galvanised .mechanical anchors shall be used.






Design codes::




* BS 6399-1, 2 :1997 for Loading

Analysis and Design







Staad model:

3D view:




Loads :

1) Dead load ( DL)










2) Live load ( LL)





3) Wind load (WL)




= 26 m/s



= Vb.Sb










Sh : topographic increment 0 .. from cl. 3.2.3.4not significant

Sb = 1.67 x 0.954 { 1 +(3.44 x 0.0884 x 1.08) + 0} = 2.11

Ve = 2.11 x 26 = 54.86 m/s


= 0.613 x 54.862

= 1.84 kN/m2






Wind in X dir & Z directions are considered separately.i.e WL-x & WL-z




1.0 DL+1.0 LL

1.0DL+1.0LL+1.0WL

(b) Design load combination :: ( for design of steel members,design of connections etc.)1.4 DL+1.6 LL

1.0DL+1.4WL

1.2DL+1.2LL+1.2WL



1.0DL+1.0WL





Refer Staad output:








Fx = 33 kN

Fy = 85 kN

Fz = 24 kN

Mz = 13.5 kNm

Use 420x320x20 thk base plate for columns.

22050

420x320X20 thk

120 base plate


Actual tension in bolt = 33/4 = 8.25 kN

Actual shear in bolt = 85/4 = 21.25 kN


shear capacity of M20 bolt = 91.9 kN > actual shear ( 21.25 kN)

End plate : ..cl.6.3.4.3, BS5950-1:2000max moment in end plate = 2 x 8.25 x 0.05 = 0.83 kNm




hence safe





Fx = 35 kN

Fy = 66.52 kN

Fz =18 kN

Mz = 23 kNm



Max tension in bolt = Fx / 4 = 35 /4 = 8.75 kN


.



End plate : ..cl.6.3.4.3, BS5950-1:2000





hence safe




Max deflection = 4.62mm < 8.6 mm ( span /250 ,,2150/250 )

.. Hence safe

6. Conclusion :





Utilization Ratio



Rev3


Analysis & Design of Cooling Tower Support Structure .Cooling tower-4

1 . Introduction


Support Structure for Back Cooling Units near inclined wall























Design codes::




* BS 6399-1, 2 :1997 for Loading

Analysis and Design







Staad model:

3D view:




Loads :1) Dead load ( DL)










2) Live load ( LL)







3) Wind load (WL)




= 26 m/s

dynamic pressure q = 0.613 x Ve2 Ve = effective wind speed

= Vb.Sb








Sh : topographic increment 0 .. from cl. 3.2.3.4. not significant

Sb = 1.67 x 0.954 { 1 +(3.44 x 0.0884 x 1.08) + 0} = 2.11

Ve = 2.11 x 26 = 54.86 m/s


= 0.613 x 54.862

= 1.84 kN/m2









i.e WL-x & WL-z


\ Load combinations will be as follows;(a) Service load combination :: ( for deflections)

1.0 DL+1.0 LL

1.0DL+1.0LL+1.0WL


1.4 DL+1.6 LL

1.0DL+1.4WL

1.2DL+1.2LL+1.2WL



Refer Staad output:





1.0DL+1.0WL






4.1 Anchor bolt Connection between columns & concrete floor/inclined wall .UB 254X146X43 is fixed to the concrete floor with M20 mechanical anchors.

Fx = 8.2 kN

Fy =70.8 kN

Fz = 8.5 kN

Mz = 10.2 kNm


22050

420x320X20 thk120 base plate



Actual shear in bolt = 70.8/4 = 17.7 kN



End plate : ..cl.6.3.4.3, BS5950-1:2000





hence safe



Fx = 55 kN

Fy = 31.22 kN

Fz =6.3 kN

Mz = 8.0 kNm







.

tensile capacity of M16 bolt = 70.3 > actual tensionshear capacity of M16 bolt = 58.9 > actual shear

End plate : ..cl.6.3.4.3, BS5950-1:2000





hence safe





.. Hence safe

6. Conclusion :





Utilization Ratio



Rev3



Cooling tower-5

1 . Introduction




















LINK MIDDLE EAST LIMITEDP.O. Box 16846, Dubai – U.A.E.Tel No. +971 4 8816750, Fax No. +971 4816250






Design codes::




* BS 6399-1, 2 :1997 for Loading

Analysis and Design







Staad model:

3D view:




Loads :

1) Dead load ( DL)










2) Live load ( LL)







3) Wind load (WL)




= 26 m/s


= Vb.Sbfor site in town terrain , ( cl.3.2.3.2.3 )








Sb = 1.67 x 0.954 { 1 +(3.44 x 0.0884 x 1.08) + 0} = 2.11

Ve = 2.11 x 26 = 54.86 m/s


= 0.613 x 54.862

= 1.84 kN/m2









i.e WL-x & WL-z




1.0 DL+1.0 LL

1.0DL+1.0LL+1.0WL


1.4 DL+1.6 LL

1.0DL+1.4WL

1.2DL+1.2LL+1.2WL



Refer Staad output:








1.0DL+1.0WL



4.1 Anchor bolt Connection between columns & concrete floor/inclined wall .


Fx = 20 kN

Fy =75 kN

Fz = 12.5 kN

Mz = 9.6 kNm


22050

420x320X20 thk

120 base plate


Actual tension in bolt = 20/4 = 5 kN

Actual shear in bolt = 75/4 = 18.75 kN

tensile capacity of M20 bolt = 110 kN > actual tension( 5kN)shear capacity of M20 bolt = 91.9 kN > actual shear ( 18.75 kN)

End plate : ..cl.6.3.4.3, BS5950-1:2000

max moment in end plate = 2 x 5 x 0.05 = 0.5 kNm




hence safe



Fx = 74 kN

Fy = 34.8 kN

Fz =11.47 kN

Mz = 27.8 kNm







.tensile capacity of M16 bolt = 70.3 > actual tension


End plate : ..cl.6.3.4.3, BS5950-1:2000





hence safe




Max deflection = 3.5mm < 8.6 mm ( span /250 ,2150/250 )

.. Hence safe

6. Conclusion :





Utilization Ratio





Rev3



Cooling tower-6

1 . Introduction



























Design codes::




* BS 6399-1, 2 :1997 for Loading

Analysis and Design







Staad model:



3D view:


Loads :

1) Dead load ( DL)










2) Live load ( LL)consider live load = 7.5 kN/m² as per BS6399 code for equipment platform..






3) Wind load (WL)




= 26 m/s


= Vb.Sb









Sb = 1.67 x 0.954 { 1 +(3.44 x 0.0884 x 1.08) + 0} = 2.11

Ve = 2.11 x 26 = 54.86 m/s


= 0.613 x 54.862

= 1.84 kN/m2









i.e WL-x & WL-z




1.0 DL+1.0 LL

1.0DL+1.0LL+1.0WL


1.4 DL+1.6 LL

1.0DL+1.4WL

1.2DL+1.2LL+1.2WL



Refer Staad output:




1.0DL+1.0WL







4.1 Anchor bolt Connection between columns & concrete floor/inclined wall .


Fx = 8.2 kN

Fy =70.8 kN

Fz = 8.5 kN

Mz = 10.2 kNm


22050

420x320X20 thk

120 base plate



Actual shear in bolt = 70.8/4 = 17.7 kN



End plate : ..cl.6.3.4.3, BS5950-1:2000





hence safe





Fx = 55 kN

Fy = 31.22 kN

Fz =6.3 kN

Mz = 8.0 kNm





.



End plate : ..cl.6.3.4.3, BS5950-1:2000


Moment capacity of end plate per unit width = py.tp²/4\Moment capacity of end plate = py.b.tp²/4


hence safe





.. Hence safe

6. Conclusion :







Utilization Ratio