Steel Structural Calculation Report

7/21/2019 Steel Structural Calculation Report

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COMMESSA/Job N: XX DIS./Dwg n : XX

CLIENTE/Client : XX PAG./Page : 1 DI/of 79

IMPIANTO/Plant : XX REV. 00 DATA/Date: XX

STEEL STRUCTURAL

CALCULATION REPORT

00 XX XX XX

REV. DATE DESCRIZIONE EMESSO CONTROLLATO APPROVATO

N° DATE DESCRIPTION ISSUED BYCONTROLLED

BYAPPROVED BY






1 CALCULATION ASSUMPTION

1.1 SCOPE

This report describes the calculation procedure and data considered in order to design the steel

structure of the HEATER.

1.2 REFERENCE DOCUMENTS & DRAWINGS

- Heater Assembly xx

- Foundation Assembly / Details with loads xx

1.3 CALCULATION CODES

- Uniform Building Code Volume 2 UBC-97

- Minimum Design Loads for Buildings and other Structures UBC-97

- Manual of steel construction - Allowable Stress Design AISC – ASD/01

- Specification for Structural Steel Buildings AISC 360-05

1.4 MATERIAL AND CODE ALLOWABLE VALUES

Material used for the structures : JIS SS400 or equivalent

Yield stress f y: 235 N/mm2(thickness ≤ 16 mm)

Minimum Tensile stress f u: 400 N/mm2






2 LOAD CALCULATION

2.1 PRIMARY LOADS

The decomposition of the loads into following primary loads :

- Structure Self-Weight (SLF):Weighs of the structural components automatically

calculated by the program, and based on the model feature.

- Extra Steelwork Weight (EXTSTEEL): Extra Steelwork weights not directly included in the modeland not automatically calculated.

- Platform (EXTPLTF):Platform Extra Steelwork weights not directly included in

the model and not automatically calculated.

- Refractory Loads (REFRACT):Weights of the refractory lining surfaces applied to the

structural elements.

- Pipe empty loads (PPEMPT):Weights of all the operating pipes installed on the structure

considered empty.

- Pipe Operating Loads (PPOPER)

Weights of the pipes filled with gas or liquid fluid as they

are during the normal operation of the plant and load at

terminal points.

- Hydrostatic test loads (PPTEST)Weights of the pipes considered full of water as they are

during the hydrostatic test conditions

- Burners (BURN): Weights of the burners applied to the radiant floor

- Air Duct (ADUCT): Weights of air duct installed on heater

- Live Load 1 (LL1):

For the calculation of the foundation loads and structural

analysis has been considered an overload of 500 Kg/m2on

each platforms.

- Wind Load +X WLX According to UBC-97

- Wind Load +Y WLY According to UBC-97

- Earthquake Load +X EQX According to UBC-97

- Earthquake Load +Y EQY According to UBC-97

- Thermal Load TMP

A thermal load has been considered on steel structures

during normal operation according to spec n° 00-ZA-E-205001-rev.02

Tmax on frame = 47°C

Tmin on frame = 2°CTmax on furnace skin = 83°C

Tmin on furnace skin = 38°C






2.2 LOADING DETAILS

2.2.1 Radiant cell

2.2.1.1 Radiant Floor

A.1 FLOOR

External Radius 2474 mm

Internal Radius 1697 mm

support internal Radius 515 mm

External Diameter 4948 mm

Internal surface diameter 3394 mm

support internal diameter 1060 mm

Floor thickness 6 mm

Overall Surface 19,2 m 2

Floor surface weight 905,7 Kg 9,06 KN

burners supporting surface 8,16 m 2

External surface 11,1 m 2

Refractory (wet) 57,04KN Wet D.ty M.W.C. 1:2:4 1930 Kg/m

3

Thickness 75 mm

Wet D.ty VLWC 1:0:5 1215 Kg/m 3

Thickness 125 mm

A 1.2 Burners

Weight of each burner considered 450 Kg

number of burners 6

Overall burners weight 2700 Kg 27,00KN

A 1.3 Steelwork

Extra steelwork not modelled 40,00 Kg/m 2

Extra steelwork weight 769,15 Kg 7,69 KN

Input Sap Data

Overall floor weight 100,79 KN

Internal surface External surface load case

KN/m2 KN/m2

Overall refractory weight distribuited on surface 2,97 2,97 REFRACTOverall steelwork weight distribuited on surface 0,4 0,4 EXTSTEEL

Overall burners weight distributed on surface 3,31 BURN






2.2.1.2 Radiant Lateral walls

LATERAL WALL

External Diameter 4948 mm

Height 9198,0 mm

Thickness 5,0 mm

Lateral Surface 142,9 m 2

Lateral surface weight 5609,1 Kg 56,1 KN

Refractory (wet) 323,7 KN

L.W.C. 124 1400 Kg/m3

Thickness 75 mm

V.L.W.C 105 1215 Kg/m3

Thickness 100 mm

Steelwork

Extra steelwork notmodelled

20,00 Kg

Extra steelwork weight 2858,1 Kg/m2 28,6 KN

tot. weight 408,4 KN

loadcase

KN/m2

Overall refractory weight distribuited on surface 2,26 REFRACT

Overall steelwork weight distribuited on surface 0,20 EXTSTEEL






2.2.1.3 Heater Arch

ARCH

Diameter 4948 mm

Thickness 6 mm

Surface 19,2 m2

Arch surface weight 905,7 Kg 9,1 KN

Rectangular hole

Lenght 4900 mm

Width 1453 mmhole surface 7,1 m2

Arch surface without hole 12,11 m2


L.W.C. 124 1400 Kg/m3

Thickness 75 mm

V.L.W.C 105 1215 Kg/m3

Thickness 125 mm

Steelwork

Extra steelwork not modelled 20,00 Kg

Extra steelwork weight 242,2 Kg/m2 2,4 KN

tot. weight 42,6 KN

Overall refractory weight added to arch surface 2,57 KN/m2 REFRACT

Overall steelwork weight added to arch surface 0,20 KN/m2 EXTSTEEL






2.2.2 Radiant Internal coil

Type of fuel Fuel Oil

Bare tubes O.D: 141,3 mmBare tubes thickness 6,55 mmBare tubes I.D. 128,2 mmMaximum Operating fluid density 556 Kg/m3Water density for hydrostatic test 1000 Kg/m3Pipe weight per meter 21,77 Kg/mOperating fluid weight per meter on each pipe 7,18 Kg/m

Water weight per meter inside each pipe 12,91 Kg/mNumber of tubes on each anchor 2,0Medium pipe lenght 7,800 mReturn bends medium diameter 254,0 mmNumber of return bends on each anchor 2,0Bends unit weight 8,7 Kg/eachOperating fluid on each return bend 2,9 Kg/eachWater weight on each return bend 5,1 Kg/each

Pipe empty weight on each anchor(2 tube + 2 bend) 356,9 KgPipe weight with operating fluid on each anchor(2 tube + 2 bend) 474,6 Kg

Pipe full weight on each anchor(2 tube + 2 bend) 568,6 Kg

Crossing TubesNumber of crossing tubes 4,0Medium pipe lenght 2,248 mEmpty crossing tubes weight 195,7 KgOperating crossing tube weight (pipes + Op. fluid) 260,3 KgTest crossing tube weight (pipes + water) 311,8 Kg

Anchor number 24,0Total number of tubes on each anchor 48,0Total number of bends on each anchor 48,0

Overall empty weight 8761,6 Kg 87,6 KNOverall operating weight (Pipe + Operating fluid) 11650,5 Kg 116,5 KNOverall test weight (Pipe + water) 13957,4 Kg 139,6 KN

Point empty weight applied on each anchor (ELEV. 19050) 3,65 KN PPEMPTPoint operating weight applied on each anchor (ELEV. 19050) 4,85 KN PPOPERPoint test weight applied on each anchor (ELEV. 19050) 5,82 KN PPTEST






2.2.3 Convection cell

2.2.3.1 Convection Lateral vertical walls

Width 4900,0 mm

Height 3555,0 mm

Thickness 5,0 mm

Surface 17,4 m2

Weight of each convection wall 683,7 Kg 6,8 KN

Refractory (wet) 36,6 KND.ty LWC 1:2:4 1400 Kg/m3

Thickness 150 mm

Steelwork not modelled

Extra steelwork not modelled 20,00 Kg/m2

Extra steelwork weight 348,4 Kg 3,5 KN

Overall convection wall weight (2X) 93,8 KN

Overall refractory weight distributed each surface 2,10 KN/m2 REFRACT

Overall steelwork weight added to each surface 0,20 KN/m2 EXTSTEEL

2.2.3.2 Convection End tube sheets (E.T.S.)

width 1453,0 mm

Height 3555,0 mm

Thickness 13,0 mm

Surface 5,2 m2

Weight of each convection wall 527,1 Kg 5,3 KN


Wet D.ty LWC 1400 Kg/m3

Thickness 100 mm

Steelwork not modelled 1,0 KN

Unit Weight 20 Kg/m2

tot. weight of each End Tube Sheet 13,5 KN

Overall End Tube Sheet weight 27,1 KN

Overall refractory weight added to each E.T.S. surface 1,40 KN/m2 REFRACT

Overall steelwork weight added each E.T.S. surface 0,20 KN/m2 EXTSTEEL






2.2.3.3 Convection Header Boxes

Deep considered for the Header boxes 450 mm

Width 2353,0 mm

Height 4455,0 mm

Surface 10,5 m2

Steelwork not modelled

sheet thickness 5,0 mm

Plate steelwork weight 411,4 Kg 4,1 KN


D.ty LWC 1:2:4 1400 Kg/m3

Thickness 50 mm

Extra Steelwork not modelled 5,24 KN

Unit Weight 50 Kg/m2

tot. weight of each Header Box 16,7 KN

Overall Header Boxes weight 33,4 KN

Overall refractory weight distributed on each E.T.S. surf. 1,42 KN/m2 REFRACT

Overall steelwork weight distributed on each E.T.S. surf. 1,81 KN/m2 EXTSTEEL






2.2.3.4 Convection Piping (coil, inlet &outlet piping)

CONVECTIVE PROCESS COIL

type of fuel fuel oil

Operating fluid density 556 Kg/m3

Water density for Hydrostatic test 1000 Kg/m3

Bare tube external diameter 141,3 mm

Bare tube thickness 6,55 mm

Bare tube internal diameter 128,2 mmBare tube length 5,226 m

Nr of flow passes 4

Number of tubes 44

N°tubes/row 4

Number of rows 11

Number of 180°return bends 40

Medum diameter of 180°return bends 254 mm

single empty tube weight per meter 21,76 Kg/m

Operating fluid weight per meter inside each tube 7,17 Kg/m

Water weight per meter inside each pipe 12,90 Kg/m

Weight of each empty bend 8,68 Kg/each

Operating fluid weight per meter inside each bend 2,86 Kg/each

Water weight per meter inside each bend curve 5,14 Kg/each

Overall empty coil weight (pipes + bends) 5350 Kg 53,50 KN

Overall Operating coil weight(pipes + bends + operating fluid)

7113 Kg 71,13 KN

Overall Test coil weight (pipes + bends + water) 8522 Kg 85,22 KN

STUDDED SURFACE AROUND CONVECTIVE COILStud height 25,40 mm

Studs diameter 12,70 mm

studs per meter 1260 stud /m

Number of bare tubes not finned

Number of studded tubes 28

studded surface length (on each tube) 5,026 m

exposed surface of each stud 0,001013 m2

studded exposed surface of each tube 6,414 m2

total exposed surface calculated (studs+ tubes) 242,04 m2

Weight of studded surface 4476,4 Kg 44,76

Overall empty coil weight 9826 Kg 98,26 KN

Overall Operating coil weight (tube + Op. fluid) 11590 Kg 115,90 KN

Overall test coil weight (tube + water) 12998 Kg 129,98 KN






Height of End Tube Sheet portion 3555,0 mm

Width of End Tube Sheet portion 1453,0 mm

Heading surface with coil weight distributed 5,17 m2

Overall empty tube weight distributed on eachconvection header surfaces

9,51 KN/m2 PPEMPT

Overall Operating weight distributed on eachconvection header surfaces (tube + Op. Fluid)

11,22 KN/m2 PPOPER

Overall test weight distributed on eachconvection header surfaces (tube + water)

12,58 KN/m2 PPTEST

2.2.3.5 Inlet & Outlet terminal points load

TAG F x F y F z M x M y M z

N N N Nm Nm Nm

N1 9342 17346 17346 7566 5694 5694

N2 9342 17346 17346 7566 5694 5694

2.2.4 Breeching

C.1 BREECHING

Base lenght 4900 mm

Base width 1453 mm

plate thickness 5 mm

Overall SAP surface 10,2 m2

C.1.1 Refractory (wet)

Wet D.ty LWC 1:2:4 1400 Kg/m3

Thickness 75 mm

Overall breeching refractory weight 1071 Kg 10,71 KN

C.1.4 Steelwork not modelled

Steelwork not modelled 30Kg/m2

Overall steelwork not modelled weight 306Kg 3,06 KN

tot. Breeching Weight 13,77 KN

Overall breeching refractory weight distributed on modelled surface1,05 KN/m2 REFRACT

Overall breeching steelwork weight distributed on modelled surface0,30 KN/m2 EXTSTEEL






2.2.5 Platforms, Vertical ladders & Stairs

Live load (for base foundation loads ) 500 Kg/m2

Grating 37 Kg/m2

Structure 75 Kg/m2

Handrail 16 Kg/m2

Toe board 7 Kg/m2

Total 135 Kg/m2

2.2.5.1 Platforms EL+ 3000 on plinth L

Dimension LengthWidth Surface

mm mm m2

Plant platform at 0° 1250 1835 2,29

nr.supportingbeam

load on middlebeam

KN/mTotal platform Deadload

309,66 Kg 3,10 KN 2 0,84

Total platform Live load 1146,88 11,47 KN 2 3,13

2.2.5.2 Platforms EL+ 3000

DimensionInternalRadius

Middleradius

modelled

ExternalRadius

Angle(°)

Surface

mm mm mm m2

Plant 2474 3104 3854 360 27,42

nr.supp.beam

load onmiddlebeam

load onexternal

beam

KN/m KN/m

Total platform Dead load 3701,77 Kg 37,02 KN 2 0,95 0,76

Kg

Total platform Live load 13710,24 137,10 KN 2 3,52 2,83






2.2.5.3 Platforms EL+9000

DimensionInternalRadius

Middleradius

modelled

ExternalRadius

Angle (°) Surface

mm mm mm m2

Plant 2474 2875 3854 345 27,42

nr.supportingbeam

load on

middlebeam

load on

externalbeam

KN/m KN/mTotalplatformDeadload

3701,77 Kg 37,02 KN 2 1,07 0,80

KgTotalplatformLive load

13710,24 137,10 KN 2 3,96 2,96

Dimension SurfaceTotallength ofbeam

modelled

m2 m

Plant platform at 270°and 90° 5,79 15,07

load onbeams

KN/mTotalplatform

Deadload

781,38 Kg 7,81 KN 0,52

TotalplatformLive load

2894,00 28,94 KN 1,92







Dimension Length Width Surface

mm mm m2





Nr ofportionconsid.

Load oneach supp.

beamcolumn

KN

Dead Load on Plant platform at 0° 606,96 Kg 6,07 KN 1 0,76




Live load on Plant platform at 0° 2248,00 Kg 22,48 KN 1 2,81





Dimension Length Width Surface

mm mm m2





Nr of portionconsid.

Load on each supportingbeam column

KN














2.2.5.6 Vertical ladder and stairs

E.1.8 Vertical ladder

load (steelwork + liveload)

Kg/mApplicable to

elev.lenght

(m)weight(Kg)

weight(KN)

80

LD.2 3000 6,00 480 4,80 KN

LD.2A 3000 6,00 480 4,80 KN

LD.3 11500 3,50 279,84 2,80 KN

LD.4 20000 3,50 279,84 2,80 KN LD.5 25010 4,71 376,4 3,76 KN

E.1.8 Stairs

load (steelwork + liveload)

Kg/mApplicable to

elev.lenght

(m)weight(Kg)

weight(KN)

300

SG.1 3000 5,25 1573,5 7,87 KN






2.2.6 Wind Loads (WL)

WIND LOAD according toUBC-97

P = Ce*Cq*qs*Iw

EXPOSURE D

Pressure coefficient on cilindrical surfaces Cq = 0,8

Site elevation 19-25 mAccording to spec. Nr. 00-ZA-E-205001 rev.2

Basic wind speed V = 44,4 m/s

According to spec. Nr. 00-ZA-E-

205001 rev.2wind stagnation pressure suggested for siteelevation qs =

1,30E-03 Mpa 1,30 KN/m2

Importance factor Iw = 1,15 (hazardous facilities)

2.2.6.1 Wind Load in X direction

FromElev.

To Elev.Frontal

dimensionSurface

consideredCe

Specific Pressure onportion p(z)

WindLoad

mm mm m m2 kN/m2 KN

Radiant 3000 7000 4948 19,8 1,48 1,77 35,0

Radiant 7000 12198 4948 25,7 1,62 1,94 49,8

convection 12198 17203 4900 24,5 1,71 2,05 50,2

Stack I 17203 27203 1574 15,7 1,83 2,19 34,4

Stack II 27203 37203 1570 15,7 1,93 2,31 36,2

Stack III 37203 47203 1566 15,7 2 2,39 37,5

Total Wind X 243,18 KN

INPUT SAP DATAPortion

Intermediatecolumns

UNITwind loaddistributed

wind load distributed ext.Columns

loadcase

Radiant 1 KN/m 4,38 2,19 WX

Radiant 1 KN/m 4,79 2,40 WX

Convection 2 KN/m 3,34 1,67 WX

Stack I 0 KN/m 3,44 WX

Stack II 0 KN/m 3,62 WX

Stack III 0 KN/m 3,75 WX






2.2.6.2 Wind Load in Y direction

WIND IN Y DIRECTION

From Elev. To Elev.Frontal

dimensionSurface

consideredCe

Specific Pressure onstack p(z)

WindLoad

mm mm m m2 kN/m2 KN

3000 7000 4948 19,8 1,48 1,77 35,0

7000 12198 4948 25,7 1,62 1,94 49,8

12198 17203 1453 7,3 1,71 2,05 14,917203 27203 1574 15,7 1,83 2,19 34,4

27203 37203 1570 15,7 1,93 2,31 36,2

37203 47203 1566 15,7 2 2,39 37,5

Total Wind Y Weight 207,89 KN

INPUT SAP DATA

PortionIntermediate

columnsUNIT

wind loaddistributed

wind load distributed ext.Columns

loadcase

Radiant 2 KN/m 2,92 1,46 WY

Radiant 2 KN/m 3,20 1,60 WY

Convection 1 KN/m 1,49 WY

Stack I 0 KN/m 3,44 WY

Stack II 0 KN/m 3,62 WY

Stack III 0 KN/m 3,75 WY






2.2.7 Earthquake Loads calculation (EQX/Y)

Earthquake load according to UBC-97(*)

Notes

Sismic Zone 4 According to spec. nr. 00-ZA-E-205001 rev.02

Seismic zone factor Z 0,4 According to table 16-I of UBC-97

Solid Profile SC According to customer data

Ca 0,40 According to table 16-Q of UBC-97 and for customer request

Cv 0,56 According to table 16-R of UBC-97 and for customer requestI 1,25

According to table 16-K“Hazardous facilities for toxic and explosives material”

R 4,5According to table 16-N of UBC-97

“Moment Resisting Frame systems – OMRF – Steel”

(*) Note:

In order to calculate the earthquake effect on the structure, the previous data have been assigned as

input data to the model in SAP 2000 program and the effect of the earthquake as base reaction,

structure elements deformation and vertical distribution of the lateral forces have been calculated

automatically.

According to UBC- 97 the automatic calculation of the elastic fundamental period of vibration

(performed by SAP 2000) is based on following formulation based on method A:

4 / 3)(*nt hC T = = 0,802 s

where:

Ct = 0,0853 is the coefficient for the calculation of steel moment-resisting frames

hn = is the height of the structure above the base (m)

from this value of T it is automatically calculated the total design base shear according to:

W T R

I C V

v **

*=

where W is the total weight of the structure.






According to UBC 97, the base shear so calculated has to respect the following limits:

The value of base shear shall not exceed the value W R

I C V

a MAX

***5.2

=

The value of base shear shall not be less than W I C V a MIN ***11.0=

For seismic zone 4 the value of base shear shall also not be less than W R

I ZN V

v Z MIN

***8,0

4 =−

Following are listed the values calculated for the heater in the different condition of work:

Work conditionTotal

weightconsidered

Total baseshear Vtot

VMAX VMIN V MIN-Z4

KN KN KN KN KNErection 1680 326 467 92.4 149.3

Operating 1748 341 485.6 96.16 155.4Test 1772 344 492.2 97.5 157.5

Operating + 33% Live 1937 379 538 106.5 172.2






2.2.8 Stack

2.2.8.1 Loading details

Stack – sections

Stack Material JIS SS400

Stack total Length 30000 mm

Internal Stack Diameter 1550 mm

Internal lining diameter 1450 mm

Stack portion I

Casing and RefractoryHeight 10000 mm

External diameter 1574 mm

Shell thickness 12 mm

Lateral External surface 49,42 m2

Casing Weight 4620,2 Kg 46,20 KN

Refractory LWC

Refractory D.ty 1400 Kg/m3

Thickness 50 mm

Overall refractory weight 3406,9 Kg 34,1 KN

Extra steel-work not modelled

Safety margin Unit Weight 20 Kg/m2

Overall Extra Steelwork Weight 988,5 Kg 9,9 KN

Base skirt / flange weightTotal base skirt weight 885,25 Kg 8,85 KN

Intermediate stiffening rings weightNumber of A-75x75x9 stiffening rings on portion 4

A-75x75x9 weight per meter 9,96 Kg/m

Total A-75x75x9 stiffening rings weight 196,90 Kg 1,97 KN

Overall Stack portion weight 100,98 KN

Overall Steelwork weight distributed along stack span 1,19 KN/m

Overall refractory weight distributed along portion span 3,41 KN/m

Point skirt weight at stack base 8,85 KN






Stack portion II






Refractory LWC


Thickness 50 mm


















Stack portion III






Refractory LWC


Thickness 50 mm






Fan duct weightOverall Fan duct supporting stiffness weight 0,00 Kg 0,00 KN

Overall fan duct steelwork weight Kg KN

Overall refractory weight Kg KN













2.2.8.2 STACK VERIFICATION

Stack stress verification are performed in according to API STANDARD 560.

Stack general dimensions

PortionFromElev.

ToElev.

Internalstack

diameter

Refractoryinternal

diameter

Shellthickness

Shell Outerdiameter

Portionheight

Stiffness ringprofile type

Nr. Ofstiffness on

span

mm mm mm mm mm

I 17200 27200 1550 1450 12 1574 10000 A-75x75x9 4II 27200 37200 1550 1450 10 1570 10000 A-75x75x9 4

III 37200 47200 1550 1450 8 1566 10000 A-75x75x10 4

Base & connecting flanges dimensions

Rectangular stiffness Triangular stiffness

PortionInternalPlate

diameter

Externalplate

diameter

Lowerplate

thickness

Upperplate

thickness

Nr. Ofstiffnesson plate

Stiffnessthickness

Height ofstiffness

Nr. Ofstiffnesson plate

Stiffnessthickness

Height ofstiffness

mm mm mm mm mm mm mm mm

I 1574 2074 30 25 28 12 270 28 12 270

II 1570 1890 30 30 0 30 8 250

III 1566 1886 30 30 0 28 8 250

Bolts Dimensions

Flanges at base of Portion Bolts nominal diameter Bolts number Bolt circle diameter

M mm

I 30 36 2060

II 27 30 1662

III 24 28 1662

LOADS ANALYSIS AND STANDARD REFERENCE

Wind action

Checks are performed according to API 560 – Specification for steel chimneys

According to the values of wind load calculated on paragraph 0 following are calculated the value of

loads and moments at the base of each section of the stack

Portion Thk.

Diameter

at portion

Base

Portion

height

Portion

casing

weight

Wind Load

uniformly

distributed

along height

Shear Load

at portion

barycentre

Moment at

portion

barycentre

Resulting

Shear at

portion

base

Resulting

moment at

portion

base

mm mm mm mm KN/m KN KNm KNm KNm

I 12 1574 10000 46,2 3,48 34,83 174,16 108,80 1660,07

II 10 1570 10000 38,5 3,63 36,33 181,63 73,97 746,24

III 8 1566 10000 30,7 3,76 37,64 188,20 37,64 188,20






According to what written in the previous paragraphs, the stack here described has the

following characteristics:

Portion ThicknessCorroded

Thickness

Conical / cilindrical Top External

Diameter

Portion

Length

Lateral

Surface

Casing

Weight

mm mm mm mm m² Kg

I 12 10 1574 10000 49,4 4620,2

II 10 8 1570 10000 49,3 3845,2

III 8 6 1566 10000 49,2 3072,3

Total 30000 147,9 11537,7

Lining thickness = 50 mm Specific weight = 1400 daN/m3

Refractory weight calculation

Portion Refractory Density Portion lenght with refractory Refractory Thickness Refractory Weight

Kg/m³ mm mm Kg

I 1400,0 10000,0 50,0 3406,9

II 1400,0 10000,0 50,0 3406,9

III 1400,0 10000,0 50,0 3406,9






Max. Height of stack: 30 m

The values above listed do not consider the effect of the corrosion on the stack walls.

The corrosion on the walls it will be considered later.

Material considered for Stack: JIS SS400

Overall Stack Height considered = 30 m

Young modulus E = 200000 N/mm²

Yield stress for the material fy = 235 N/mm²

Lining Thickness = 50 mmLining density = 1400 Kg/m³

Overall casing lateral surface 147,9 m²

Overall Casing weight 115,38 KN

Overall lining weight 102,21 KN

Overall extra weight for Equipments appended: 0 KN

Overall extra steelwork, stiffening and flanges weight 53,23 KN

Total platform surface considered 0 m²Overall structural platform weight 0 KN

Live load considered on each platform surface 2 KN/m²

Overall non permanent live load 0 KN

Overall ladder length 0 m

Overall ladder weight 0 KN

Overall stack permanent weight 270,82 KN

Overall weight with 33% of live load 270,82 KN

Maximum resulting shear at stack base 108,8 KN

Maximum resulting moment at stack base 1660,08 KMn






ANCHOR BOLTS AND GROUND RING

The design procedure described in this paragraph is written according to chapter 10 of the book :

“Process Equipment Design”

Written by: L.E. Brownell and E.H. Young

Publisher: Wiley Publishing

Bearing plate thickness assumed t4 = 30 mm

Compression plate thickness assumed t5 = 25 mmGusset plate thickness assumed t6 = 12 mm

Base plate outer diameter De = 2074 mm

Base plate bolt circle diameter Db = 2060 mm

Base plate inner diameter Di = 1574 mm

Minimum vertical load on base plate Nmin = 270,82 KN

Maximum vertical load on base plate Nmin = 270,82 KN

Maximum shear load at stack base Vmax = 108,8 KN

Maximum resulting moment at stack base Mmax = 1660,08 KNm

Number of bolts on base plate nb = 36

Nominal diameter of anchor bolts db = 30 mm

Resistance section of anchor bolts Ares = 561 mm²

Safety coefficient on yield stress n= 1,5

Admissible stress for parts resistance checkσadm = 156,67 N/mm²

Max load on anchor bolts is given by:

Nb =(-Nmin/nb)+(4Mmax/Nb*Db) = 82,02 KN






Bearing plate design procedure:

Stress on net section of anchor bolt:

σb = Nb/Ab = 14,62 KN/cm2 VERIFIED

Maximum compression stress

σc = Nmax/(3,14*Db*c) + 4*Mmax/(3,14*Db2*c) = 0,22 KN/cm2

where:

c: Ring outer radius - medium shell radius = 1037 - 781 = 256 mm

Base plate is defined as follows:

distance between stiffening bmin = 150 mm

distance between stiffening bmax = 300 mm

external width of base plate l = 250 mm

ratio (l/ b)max = 0,834 mm

thickness of bearing plate tb = (6*Mmax/ σadm)0,5

= 29,6 mm

Where Mmax is calculated with the formulas:

Mmax = c1*σb*b2 = 14,53 KNcm with c1 = 0,0765 by interpolation

Mmax = c2*σb*b2 = 22,82 KNcm with c2 = -0,173 by interpolation

the value of “tb” has to be checked where the bolts are located

In order to do this the maximum bolt load P is given by the formula:

P = sb*Ab = 87,9 KN

Whereσb is the maximum stress admissible on bolts

The Maximum bending moment supported by bolts is given by:

Mmax = P*b/8 = 329,59 KN/cm

The bearing plate thickness calculated with the considerations above is:

tb=(6*Mmax/(lt-bhd)*σadm)0,5

= 24,2 mm THICKNESS t4 ASSUMED VERIFIED

Where:

lt : overall bearing plate width = 250 mm

bhd :bolt hole diameter in bearing plate = 33 mm






Compression plate design procedure:

The thickness of the compression plate is calculated as follow:

Mymax = (P/4*π)*[(1,3*ln(2*l/ π*e)+(1-g1)] = 15,95 KNcm

Where:

Mmax: Maximum bending moment acting on compression plate

P: Maximum bolt load calculated above

lc : Radial distance from outside of skirt to outer edge of compression plate

e: One-half distance across flats of bolting nuts = 23 mm

g1: Constant = 0,472 (by interpolation)

The thickness of the compression plate is:

tc =(6*Mymax/sigma_amm)0,5

= 24,7 mm THICKNESS t5 ASSUMED VERIFIED

Vertical gussets plate design procedure:

The vertical gusset plated equally spaced may be considered to react as a vertical column.

From empirical calculations it comes that the minimum thickness required for the gusset plates

is given by the equation:

18000*l*tg³-P*tg²-h²*P/1500=0

Where:

l: is the width of the gussets (inches)

h: is the height of the gussets (inches)tg: is the thickness of the gussets (inches)

P: is the Maximum value of bolt load calculated (lbs)

According to the values above listed the minimum thickness required for the gussets is:

tg = 6,25 mm THICKNESS t6 ASSUMED VERIFIED






INTERMEDIATE RING FLANGES STRESS CHECK

Flange Stress Check

The procedure considered for the stress check of the flanges is the following:

The maximum pressure on flange due to vertical load is given by:

()4

22max

pi pe f

V D D

P

A

P p

−⋅==

−

π

The uniform load on middle flange diameter due to Pmas-V is given by:

⎟⎟

⎟

⎟

⎟⎟

⎟

⎟ −⋅=

−−

2maxmax

pi pe

V V p

D D pq

Assuming that the neutral axis for maximum moment passes from the section axis and

assuming that the highest pressure value is located on bolt circle diameter, the maximum

pressure on flange due to wind is given by:

()2

22max

cb pi pe

Max

cb f

MaxW

D D D M

D A M p ⋅−==−

π

Assuming that this pressure is uniformly distributed on compressed side of the flange it

can be calculated the uniform load on middle flange diameter due to this pressure:

⎟⎟

⎟

⎟

⎟⎟

⎟

⎟ −⋅⋅=

−−

22 maxmax

pi pe

W W p

D D pq

Where:

P: is the maximum vertical load calculated at the base of the section consideredMmax is the maximum moment calculated at the base of the section considered

Dpe & Dpi are the Outside and the Inside flange diametersDcb is the Bolt Circle diameter

the worst load combination is given in the position where the two loads add one to the

other:

W pV p qqq −−+=

maxmaxmax

With the geometry assumed it follows that the distance between the stiffness on bolt

circle diameter is given by:

s

s

cbt

N

Db −=

πmax






where:

ts is the thickness of the stiffness

Ns is the total number of stiffness (assumed)

Now each flange can be assumed as a beam simply supported in the position where it

joins to the stiffness, so the maximum moment calculated between the two supports is

given by:

8

2

maxmax bq

M f

⋅=

The stress check of the flange is verified if

f adm

f

f

Mf t b

M −

≤⋅

= σσ

6

2

max

where:

tf is the thickness of the flange (assumed)

In order to check the maximum stress of the stiffness placed on each flange they arecalculated the maximum shear load and the maximum moment acting at the base of each

stiffness.

In order to do this, the flange is considered as a beam uniformly loaded and supported by

each stiffness.

From this consideration the maximum reaction and the maximum moment calculated

under the stiffness are given by the equations:

maxmaxmax2

1bq R s

=−

2

maxmaxmax12

1bq M s

=−

From these values it is easy to calculate the maximum shear and bending stresses:

ss

st h

Rmaxmax =

−τ 2

maxmax

6

ss

sht

M =−σ

where:

ts is the thickness of the stiffness (assumed)

hs is the height of the stiffness (assumed)

The stress of the stiffness is verified if

f admsssid −−−− ≤+= στσσ

2

max

2

max 3






Following are listed all the geometric data and the resulting value calculated according to the

procedure above described.

Flange at base of

portion

Stack External

DIA

Stack Shell

Thk

Flange

Outside Dia

Flange

inside Dia

Flange circular

surface

Flange

thk

Dext ts Dpe Dpi Af tf

mm mm mm mm mm2 mm

II 1570 10 1890 1570 869152 30

III 1566 8 1886 1566 867142,4 30

Section Bolt Circle diameter Nr. of stiffness on interm. flange Stiffness Height Stiffness Thk

Dcb Ns hs ts

mm mm mm

II 1662 30 250 8

III 1662 28 250 8

Section

Max

Verticalload on

flange

Max moment at

section base dueto wind or

earthquake

Max

pressure on

flange due to

vertical load

Uniform loadon middle

diameter due

to vertical

load

Max

pressure on

flange due

to wind

uniform load

on middle

diameter due

to wind

Max

uniform

load on

flange

PMax Mmax Pmax-V qpmax-V Pmax-W qpmax-W qmax

KN KNm N/mm2 N/mm N/mm2 N/mm N/mm

II 169,84 746,24 0,20 31,26 0,52 82,66 113,92

III 81,02 188,20 0,09 14,95 0,13 20,89 35,84

Section distance between the stiffness Max Bending moment on flange Max stress on flange Check

bmax Mf sMf

mm KNm N/mm2

II 189,46 0,51 17,99 OK

III 203,06 0,18 6,07 OK

SectionMax reaction

under stiffness

Max moment

under stiffness

Max bending

stress on Stiffness

Max shear stress

on Stiffness

Max ideal stress

on StiffnessCheck

Rmax-s Mmax-s smax-s tmax-s sid-s

KN KNm N/mm2 N/mm2 N/mm2

II 26,98 0,29 3,45 13,49 23,62 OK

III 9,10 0,10 1,25 4,55 7,98 OK






Flange bolts stress check

The flange bolts considered in the following procedures are in class 8.8 with the

following values for admissible stress:

σadm-b = 373 N/mm2

τadm-b = 264 N/mm2

The procedure considered for the stress check of the flange bolts is the following:

The maximum axial load on each bolt is given by the difference of the axial load due to

bending moment at the base of each section and the minimum vertical load calculated in

the same section.

The maximum axial load on worst stressed bolt is given by:

bcbb

b N n

N

Dn

M F

minmax4−=

−

From this follows that the highest axial stress on bolts is given by:

res

b N b

AF −− =maxσ

The maximum shear stress on each bolt is given by:

bres

bn A

V maxmax =

−τ

where:

Nmin is the minimum vertical load calculated at the base of the section considered

Vmax is the maximum shear load calculated at the base of the section considered

Mmax is the maximum bending moment calculated at the base of the section

considered

Dcb is the bolt circle diameternb is the total number of bolts considered on the flange

Ares is the resistance section of the bolts considered

The bolt are verified if

badmbbbid −−−− ≤+= στσσ

2

max

2

max 3






The data and the results of the procedure applied to each intermediate flange are following listed:

SectionStack

Ext. Dia.

Stack

Shell thk.

Nr. of bolts on

interm. flange

Bolt

circle dia.

Bolt hole dia.

on flange

Bolt

nominal Dia.

Bolt resistance

section

Dext ts Nb Db db M Ares

mm mm mm mm mm 0 mm2

II 1570 10 30 1662 30 27 459

III 1566 8 28 1662 27 24 353

Section

Min

Vertical

load on

flange

Max shear

load due to

wind or

earthquake

Max moment at

section base due

to wind or

earthquake

Max axial

load on

worst

stressed

bolt

Max

axial

stress on

bolts

Max

shear

stress on

bolts

Max

ideal

stress on

bolts

Check

PMin VMax Mmax FN-b smax-b tmax-b sid-b

KN KN KNm KN N/mm2 N/mm2 N/mm2

II 169,8 74,0 746,2 54,2 118,1 5,4 118,5 OK

III 81,0 37,6 188,2 13,3 37,6 3,8 38,2 OK






CHECK OF CASING

With reference to the stack structure section, considering that the ratio between diameter (D) and thickness (t) is

very high, in the following they will be used simplified formulas:

A = π*D*t

W = (π*D2*t)/4

I = (π*D3*t)/8

Specific data for resistance check (thickness of corrosion = 2 mm)

PortionWall thickness

corroded

External

corroded

diameter

A W I

Corroded

casing

weight

mm mm cm² cm 3 cm 4 KN

I 10 1570 493 19.359 1.519.703 38,70

II 8 1566 394 15.409 1.206.494 30,88

III 6 1562 294 11.497 897.954 23,10

The overall structure stability value does not consider possible allowances due to fabrication, while the

possible corrosion allowance value is deducted at checks of resistance.

VERIFICATION

Check on stability are performed in connection with admissible compression stresses, as per API 560 Par. 9.3.

Admissible compression stress is the minimum value between:

σadm-1 = 0,5*Fy = 11,75 N/mm²

or

σadm-2= 0,56*E*t/(D*(1+(0,004*E/Fy)))

With values defined as follows:

t = is the corroded shell plate thickness (mm)

D = is the outside stack diameter (mm)

E = 200000 N/mm² is the Elastic Young Modulus

Fy = 235 N/mm² :is the material minimum yield strength at design temperature

Following are listed the data considered in order to check the stress status of each shell section.

The value of stress on each section is calculated with the vertical load coming from the weight calculationof each section considered with thickness corroded






PortionFrom

Elevation

To

Elevation

Max Vertical

Load at portion

base (N)

Max Moment at

portion base

(Mmax)

Stress

Calculated at

base portionσadm-2 Check

mm mm KN KNm cm4 KN/cm2

I 17200 27200 271 1.660 9,124 16,20 VERIFIED

II 27200 37200 170 746 5,275 12,99 VERIFIED

III 37200 47200 81 188 1,912 9,77 VERIFIED

DYNAMIC CHECK ON WIND EFFECT

DYNAMIC CHECK

Dynamic check is performed according to point 9.5 of API 560.

Vc1 = 5*Dt*f Vc2 = 6*Vc1

Where:Dt = 1,562 m Diameter of stack top

f = first mode frequency

f = 0,5587*(E*I*g/W*H4)

0,5

where:

W = 46,33 lbs/in is the Weight per unit height of stack

E = 29007548,8 psi is the Young Elastic Modulus

g = 386 in/s2

is acceleration due to gravity

I = 29023,3 inch4 is the medium moment of inertia

H = 1181,1 in is the total stack height

f = 1,061 Hz

Vc1 = 5*Dt*f = 8,29 m/s ACCEPTABLE WITH STRAKESVc2 = 6*Vc1 = 49,71 m/s ACCEPTABLE






STIFFENING RING PRESENCE CHECK

Dynamic check is performed according to point 9.5.5 of API 560

Stiffening ring are required to prevent ovalling if:

fr/2*fv<1

calculated with the formulas:

fr = 0.126*(tr*(E)0,5

)/Dr2

fv = 13.2/Dr

Where

fr = natural frequency of the free ring (cycle per second)

fv = vortex shedding frequency (cycle per second)

tr = corroded plate thickness (inches)

E = Young Elastic Modulus (psi)

Dr = internal stack diameter (feet)

PortionFrom

Elevation

To

Elevation

Internal

Diameter

Shell

Thickness

corroded

Stiffening

Spacingfr fv fr/2fv Check

mm mm mm mm m

I 17200 27200 1.550 10 2,00 10,3372,60 1,99RINGS NOT

REQUIRED

II 27200 37200 1.550 8 2,00 8,269 2,60 1,59RINGS NOT

REQUIRED

III 37200 47200 1.550 6 2,00 6,202 2,60 1,19RINGS NOT

REQUIRED






2.3 LOADING COMBINATIONS

2.3.1 Main LoadsThe following main loads have been considered

Deads = SLF + ADUCT + BURN + EXTPLTF + EXTSTEEL + REFRACT

ERECT = Deads + PPEMPT

OPER = Deads + PPOPER

TEST = Deads + PPTEST

LT = TMP + LIVE1

Live Load LIVE1

Wind Load +X WLX

Wind Load +Y WLY

Earthquake Load +X EQX

Earthquake Load +Y EQY

Thermal Load TMP

2.3.2 Load Combinations

Combination with Erection conditions

CB1E = ERECT + LIVE1

CB2E = ERECT + WX

CB3E = ERECT - WX

CB4E = ERECT + WY

CB5E = ERECT - WY

CB6E = ERECT + 0,714*EQX

CB7E = ERECT -0,714*EQX

CB8E = ERECT + 0,714*EQY

CB9E = ERECT -0,714*EQYCB10E = 0,9*ERECT + 0,714*EQX

CB11E = 0,9*ERECT -0,714*EQX

CB12E = 0,9*ERECT + 0,714*EQY

CB13E = 0,9*ERECT -0,714*EQY

CB14E = ERECT + 0,75*LIVE1 + 0,75*WX

CB15E = ERECT + 0,75*LIVE1 -0,75*WX

CB16E = ERECT + 0,75*LIVE1 + 0,75*WY

CB17E = ERECT + 0,75*LIVE1 -0,75*WY

CB18E = ERECT + 0,75*LIVE1 + 0,535*EQX

CB19E = ERECT + 0,75*LIVE1 -0,535*EQXCB20E = ERECT + 0,75*LIVE1 + 0,535*EQY

CB21E = ERECT + 0,75*LIVE1 -0,535*EQY






Combination with Operating conditions

CB1O = OPER + LIVE1

CB2O = OPER + WX

CB3O = OPER - WX

CB4O = OPER + WY

CB5O = OPER - WY

CB6O = OPER + 0,714*EQXCB7O = OPER -0,714*EQX

CB8O = OPER + 0,714*EQY

CB9O = OPER -0,714*EQY

CB10O = 0,9*OPER + 0,714*EQX

CB11O = 0,9*OPER -0,714*EQX

CB12O = 0,9*OPER + 0,714*EQY

CB13O = 0,9*OPER -0,714*EQY

CB14O = OPER + 0,75*LIVE1 + 0,75*WX

CB15O = OPER + 0,75*LIVE1 -0,75*WX

CB16O = OPER + 0,75*LIVE1 + 0,75*WY

CB17O = OPER + 0,75*LIVE1 -0,75*WY

CB18O = OPER + 0,75*LIVE1 + 0,535*EQX

CB19O = OPER + 0,75*LIVE1 -0,535*EQX

CB20O = OPER + 0,75*LIVE1 + 0,535*EQY

CB21O = OPER + 0,75*LIVE1 -0,535*EQY

CB1OT = OPER + LT

CB14OT = OPER + 0,75*LT + 0,75*WX

CB15OT = OPER + 0,75*LT -0,75*WX

CB16OT = OPER + 0,75*LT + 0,75*WY

CB17OT = OPER + 0,75*LT -0,75*WY

CB18OT = OPER + 0,75*LT + 0,535*EQX

CB19OT = OPER + 0,75*LT -0,535*EQX

CB20OT = OPER + 0,75*LT + 0,535*EQY

CB21OT = OPER + 0,75*LT -0,535*EQY






Combination with Test conditions

CB1T = TEST + LIVE1

CB2T = TEST + WX

CB3T = TEST - WX

CB4T = TEST + WY

CB5T = TEST - WY

CB6T = TEST + 0,714*EQX

CB7T = TEST -0,714*EQX

CB8T = TEST + 0,714*EQY

CB9T = TEST -0,714*EQY

CB10T = 0,9*TEST + 0,714*EQX

CB11T = 0,9*TEST -0,714*EQX

CB12T = 0,9*TEST + 0,714*EQY

CB13T = 0,9*TEST -0,714*EQY

CB14T = TEST + 0,75*LIVE1 + 0,75*WX

CB15T = TEST + 0,75*LIVE1 -0,75*WX

CB16T = TEST + 0,75*LIVE1 + 0,75*WY

CB17T = TEST + 0,75*LIVE1 -0,75*WY

CB18T = TEST + 0,75*LIVE1 + 0,535*EQX

CB19T = TEST + 0,75*LIVE1 -0,535*EQX

CB20T = TEST + 0,75*LIVE1 + 0,535*EQY

CB21T = TEST + 0,75*LIVE1 -0,535*EQY






3 STRUCTURE SYSTEM

3.1 THE MODEL






3.2 BAR ELEMENTS NUMBERING

3.2.1 Frame numbering - Arch






3.2.2 Frame numbering - Convection






3.2.3 Frame numbering - Floor






3.2.4 Frame numbering - Platform el. 9000






3.2.5 Frame numbering - Platform el. 17203






3.2.6 Frame numbering - Radiant body






3.2.7 Frame Profiles - Radiant body

H-200x200

C-200x80

A-75x6

C-150x75 LL-150x100

2A-90x10






3.2.8 Frame Profiles –Stack






3.3 PRIMARY LOADS APPLICATION

3.3.1 Burners weight distribution






3.3.2 Coil weight distribution on convection surface






3.3.3 Coil weight distribution on radiant anchor






3.3.4 External piping loads






3.3.5 Platform weight and live load distribution






3.3.6 Refractory & Extrasteel weight distribution






3.3.7 Wind load distribution in X direction






3.3.8 Wind load distribution in Y direction






4 STRUCTURAL ANALYSIS

The Steel Structure is checked in accordance with ASC-ASD-1989.

Automatic members check is carried out by means of SAP 2000 – Steel Stress Check according

ASC-ASD-1989.

Structural checks and frame analysis are based on 3-d structure model.

The bars and the shells elements ave been designed for the worst loading combination cases.

5 BASE PLATE AND ANCHOR BOLTS CHECK

5.1 BASE PLATE CHECK

5.1.1 Base Plates stress check calculation procedure

In order to check the worst stress status of the plates at the base of the structure columns the

following procedure has to be performed.

The calculation of the maximum stress on the concrete plinths is performed considering thevalue of the eccentricity calculated as ratio between the value of the moment acting at the

base of the columns (M) and the compression load perpendicular to the base plate (N).

N

M e =

The value of this ratio detects the position of the neutral axis with respect to the kernel of

inertia of the section calculated as sixth part of the plate dimension perpendicular to the axis

of the moment considered (a) as shown in the following picture (where the load N has not to

be considered as a shear load but only an image for the position of the perpendicular load):

Picture 1






According to the value of “e” calculated, the two following conditions have to be considered:

Condition 1 for calculation of maximum stress on plinth:

6

ae ≤ : eccentricity internal to the kernel of inertia

in this case the plinth can be assumed to be forced by only a compression load, so the

maximum compression stress on plinth is calculated as follows:

ccc

W

M

A

N

+=σ

where:

Ac : is the section area of the cement plinth

Wc: is the elastic modulus of the plinth

For conservative reasons both the geometric characteristics above listed are calculated

considering the plinth with same dimensions and section of the base plate.

The stress of the maximum compression on plinth is verified if :

ck c R*44,0≤σ

where Rck is the cubic admissible resistance of the concrete considered.

From the value of σc, it is calculated for proportion the value of the stress acting on the baseplate in correspondence of the section column flanges or stiffeners:

sc

s

s

sc x

a x x 2

σσ

σσ=⇒=

where assuming the neutral axis passing from the middle of the section:

σs is the value of sigma at stiffeners level

xs is the distance between stiffeners and neutral axis






Condition 2 for calculation of maximum stress on plinth:

6

ae > : eccentricity external to the kernel of inertia

this condition forces to the research of the position of the real neutral axis.

The value of the position of the neutral axis is found by attempts with the following empirical

equation:

0)()(26

23=+−+++ hd hnA xhd nA x

bd x

b f f

Where (ref. to picture 1):

b is the plate dimension parallel to the moment axis

x is the position of the neutral axis with respect to the base edge

d is the position of perpendicular load with respect the plate edge

n = 15 is the homogenization coefficient between elastic modulus

Af = Ab*nb is the total area of the bolts strengthen

h is the distance between the base edge and the axis of the anchor bolts

strengthen

Once that the value of “x” is calculated the value of the maximum sigma acting on the cement

plinth is calculated with the formula:

)(2

*2

xhnA x

b

x N

f

c

−−

=σ

The stress of the maximum compression on plinth is verified if :

ck c R*44,0≤σ

where Rck is the cubic admissible resistance of the concrete considered.

From the value of σc, it is calculated for proportion the value of the stress acting on the base

plate in correspondence of the section column flanges or stiffness:

sc

s

s

sc x

x x x

σσ

σσ=⇒=

where (ref. to picture 1):

σs is the value of sigma at stiffness level

xs = x- m1 is the distance between stiffness and neutral axis






Base Plate stress calculation

Once that the values of σc and σs have been calculated from one of the procedures above

described the stress check of the base plate continues as follows for both the conditions:

The base plate is now considered as a beam rigidly joined at level of stiffness and uniformly

loaded by a load “q” calculated as follows:

2*1 sc

mqσσ +

=

The maximum momentum given by this kind of restraint is:

2

2*

8

2*22

mqlq M Max

−=

where

l2 is the intermediate distance between the base plate stiffeners

m2 is the distance between the flange of the column section and the plate edge

The Maximum sigma acting on the flange is:

⎟⎟

⎟

⎟

⎟⎟

⎟

⎟

==

6*1 2thk m

M

W

M Max Max

p

σ

Where:

W is the resistance modulus of the section considered.

thk is the thickness of the plate (assumed)

Note:

The procedures above described are referred to a moment with axis parallel to direction 2.

In the case in which the moment considered is directed as axis 1 the related values of

geometric dimensions as “a”, “b”, “l”, “m” etc have to be considered.

In order to take into account the effect of both the moments acting at the base of the column,

the procedures above described are performed considering one at time both the moments

acting on the two main direction of the section.

The value of stress so found it has to be lower than the admissible stress calculated as ratio

between the yield stress of the material considered for the base plate and a safety coefficient.

If the stress is verified the thickness assumed has not to be increased.






5.1.2 Stress check on Base Plates A – B – C – D – E – F

Plinth Comb. Fn F1 F2 M1 M2

KN KN KN KNm KNmF CB7O 950,4 60,7 -15,1 5,8 25,4

Yield Stress of the material JIS SS400 = 235 N/mm²Admissible stress of the base plate material = 235 / 1,5 = 156,67 N/mm²

Cement Plinth cubic resistance Rck = 21 N/mm²

Admissible stress on cement plinth = 21 * 0,44 = 9,24 N/mm²

Base Plate thickness assumed = 35 mm

Considered 8 bolts M30






Action

dominant

Plate

dimension

parallel to

Moment (b)

Plate dimension

perpendicular to

Moment (a)

Plinth

section

(Ac)

Plinth

Elastic

modulus

(Wc)

Eccentricity

(e)

eccentricity

case

mm mm mm² mm³ mm

M1 500 500 250000 20833333 6,12 Case 1: e<a/6

M2 500 500 250000 20833333 26,71 Case 1: e<a/6

Action

dominant

Distanceof

normal

force

from

edge

(d)

Nr. of bolts

strengthen

on last row

(nb)

Totalresistance

section of

bolts

strengthen

(Af)

Distancebetween

bolts

strengthen

and plate

edge

(h)

Distancebetween

Neutral

axis and

plate

edge

(x)

Distancebetween

stiffness

perp. to

moment

(l2)

Distance

betweenstiffness

and plate

edge

perp. to

moment

(m2)

Distance

betweenstiffness

and plate

edge

parallel

to

moment

(l1)mm mm mm² mm mm mm mm mm

M1 0 3 1683 425 0 200 138 150

M2 0 3 1683 425 0 176 150 138

Action

dominant

Compression

Stress on

Plinth (σσσσσσσσσc)

Plinth stress

check

Sigma on

stiffeness for

proportion

(σσσσσσσσσf )

uniform

load on

plate

portion

(q)

Maximum

moment on

plate portion

(ΜΜΜΜΜΜΜΜΜmax)

Resistance

module with

respect to the

moment

(Wp)N/mm² N/mm² N/mm Nmm mm³

M1 0,28 Sigma-c CLS OK 2,37 529,47 3906450,71 28175,00

M2 1,22 Sigma-c CLS OK 2,12 556,44 2516204,32 30625,00

Action

dominant

Sigma on base plate for Moment

effect (σσσσσσσσσp)

Sigma resultant from both moment

action (σσσσσσσσσmax)

Plate stress

check

N/mm² N/mm²

M1 138,65

M2 82,16138,65 Plate check OK






5.2 ANCHOR BOLTS CHECK

5.2.1 Anchor bolts on plinth A B C D E F according to Chapter J of AISC-350-05

In order to perform the check resistance of the bolts following are listed the calculation made

for the load combinations that make the higher stress on bolts in condition of maximum and

minimum axial load, moment and resulting shear.

According to this in order to calculate the axial and shear stress on worst stressed bolt thefollowing equations have been considered:

Axial load on bolt due to Fn (in strength condition)()

bb

nFnt

An

F f

⋅=

−

Axial load due to moment in X direction∑

=− 2

max

**

*

ibbx

x Mxt

y An

y M f

Axial load due to moment in Y direction∑

=− 2

max

**

*

ibby

y

M t x An

x M f

y

Overall axial load on bolt Myt Mxt F t nt f f f f n −−− ++=

Overall Shear Load22

y xtot V V V +=

Shear Load Acting on each bolt:

b

tot b

n

V V =

Required Shear stress on each bolt:b

bnv

A

V f =

Where:

nb : overall number of boltsAb : Resistance section of each bolt

ymax / xmax: Distance between the plate edge and the farest bolt line parallel to x / y axis

yi / xi: Distance between the plate edge and each bolt line parallel to x / y axis

nbx / nby: number of bolts on the farest bolt line parallel to x / y axis






Once that the axial and shear stresses on bolt are calculated as previous described the design

procedure (according to Chapter J of AISC-350-05) can be applied as follows:

Design procedure according to Chapter J of AISC-350-05Specified minimum tensile strength of the type of steel being used Fu = 400 N/mm

2

Nominal tensile Stress acc. AISC 350 cap.J Fnt = 0,75*Fu = 300 N/mm2

Nominal shear Stress acc. AISC 350 cap.J Fnv = 0,4*Fu= 160 N/mm2

For tensile stress check the values are:

Ra = f nt * Ab ''

nt n F F = is the nominal tensile stress modified to include the effects of shearing stress

calculated with the equation:

2

'1

Ω−=

nv

nvnt nt

F

f F F

For combined tension and shear actions it has to be:Ω

=Ω

≤ bnna

AF R R

'

Where:Ra : is the required strength (ASD)

Rn is nominal strength

Ω = 2 is the safety factor (ASD)

Total bolt number 8

Nominal bolt diameter 30

Section resistance 561 mm²

Specified minimum tensile strength of the type of steel being used Fu = 400 N/mm²

Nominal tensile Stress acc. AISC 350 cap.J Fnt =0,75*Fu 300 N/mm²

Nominal shear Stress acc. AISC 350 cap.J Fnv =0,4*Fu 160 N/mm²






According to the procedure above described following are listed the values calculated with the

load combination that makes higher status of axial, moment and shear on anchor bolts:

Plinth Combo FN FX FY MX MY Max base shear

KN KN KN KN-m KN-m KN

Combination with Max vertical load at base F CB7O 950,4 60,7 -15,1 5,8 25,4 62,5

Combination with Min vertical load at base C CB11O -438,9 51,3 4,8 -1,8 24,8 51,6

Combination with Max moment Mx at baseA CB15OT 545,9 -8,5 -44,2

25,5-6,7 45,0

Combination with Min moment Mx at base D CB21OT 660,4 24,0 43,1 -24,7 9,8 49,3

Combination with Max moment My at base F CB15OT 840,3 68,3 -14,4 840,3 32,7 69,8

Combination with Min moment My at base C CB14OT 724,7 -47,7 3,6 -1,4 -27,5 47,8

Combination with Max resulting shear at base F CB19OT860,39 71,70 -15,21 5,87 32,25 73,30

Requiredtensile

stress oneach bolt ft

Overallshear

load onplinthVtot

Requiredshear

sterss oneach bolt

fnv

nominaltensile stressmodified toinclude theeffects ofshearing

stress F'nt

requiredstrength

Ra

nominalstrength

Rn/ Ωcheck

Plinth Combo N/mm² KN N/mm² N/mm² N/mm² N/mm²

Max Fz F CB7O 31,7 62,5 13,9 295,4 17771,4 82865,5 OK

Min Fz C CB11O 124,8 51,6 11,5 296,9 70001,7 83278,0 OK

Max Mx A CB15OT 32,8 45,0 10,0 297,6 18373,5 83485,9 OK

Min Mx D CB21OT 35,0 49,3 11,0 297,2 19636,2 83353,0 OK

Max My F CB15OT 38,8 69,8 15,6 294,3 21787,6 82544,4 OK

Min My C CB14OT 29,4 47,8 10,6 297,3 16487,3 83401,1 OK

Max shear F CB19OT 38,7 73,3 16,3 293,7 21709,6 82377,9 OK






6 RESULTS ANALYSIS

6.1 LOAD FOUNDATIONS






6.2 DISPLACEMENTS CHECKING6.2.1 Max Horizontal Joint displacement

Maximum horizontal displacement: 7.56 mm

Column height: 5005

Load Combination: CB6E

Joint : 803

Allowable displacement checking for column height:

h0 /500 = 5050/500 = 10.01 mm > 7.56 OK






6.2.2 Max deflection of beam

Maximum deflection : -6.63 mm

Beam Span (L): 1800

Load Combination: CB10

Beam number : 572

Allowable deflection checking:

L/250 = 1500/250 = 7.2 mm > 6.63 OK






6.3 STRESS CHECKING

In the following pictures are the Design Stress Ratios Topography per line provided SAP.

These ratios correspond to the design stress in the bars over the allowable stress.

6.3.1 Maximum stress in main elements

Here below the maximum stress ratios in the main structural elements

Frame DesignSect DesignType Combo TotalRatio

211 C-150X75 Beam CB17O 0,970

112 H-200X200 Column CB3O 0,954

418 2A-75X9 Brace CB15OT 0,926

Here below the computer output detailed structural calculations of the main elements with the

maximum stress above mentioned.






6.3.2 Data for worst stressed beam






6.3.3 Data for worst stressed column






6.3.4 Data for worst stressed brace






6.3.5 Stress Ratios - Arch






6.3.6 Stress Ratios - Convection






6.3.7 Stress Ratios - Floor






6.3.8 Stress Ratios - Platform el. 9000






6.3.9 Stress Ratios - Platform el. 17203






6.3.10 Stress Ratios - Radiant Body






Structural elements stress checking computer output table

TABLE: Steel Design 2 - PMM Details - AISC-ASD 01

Table: Steel Design 2 - PMM Details - AISC-ASD01

Frame DesignSect DesignType Combo TotalRatio PRatio MMajRatio MMinRatio

211 C-150X75 Beam CB17O 0,970486 0,033793 0,080941 0,855752

1456 A-75X6 Beam CB1OT 0,965219 0,161650 0,254303 0,549266

112 H-200X200 Column CB3O 0,953768 0,756447 0,196224 0,001097

600 A-75X6 Beam CB14OT 0,953275 0,165027 0,358192 0,430056

604 A-75X6 Beam CB5O 0,943607 0,084699 0,288275 0,570633624 A-75X6 Beam CB15OT 0,942381 0,132440 0,242276 0,567665

1401 A-75X6 Beam CB15OT 0,937742 0,202521 0,308597 0,426625

1493 A-75X6 Beam CB16OT 0,937390 0,204937 0,291222 0,441231

421 C-150+A-90 Beam CB16OT 0,935003 0,035953 0,505647 0,393404

1478 A-75X6 Beam CB1OT 0,929110 0,147188 0,250400 0,531521

571 2A-90X10 Column CB5O 0,926956 0,358888 0,361460 0,206608

418 2A-75X9 Brace CB15OT 0,925765 0,034595 0,442762 0,448408

1480 A-75X6 Beam CB1OT 0,924432 0,147620 0,255147 0,521665

580 A-75X6 Beam CB14OT 0,923496 0,147784 0,275288 0,500425

649 A-75X6 Beam CB1OT 0,919039 0,033808 0,064643 0,820587

53 H-200X200 Column CB17OT 0,917472 0,472758 0,222467 0,222247

374 A-75X6 Beam CB1E 0,912147 0,042444 0,066102 0,803601

648 A-75X6 Beam CB1OT 0,909268 0,030118 0,018807 0,860343182 H-200X200 Beam CB2T 0,908771 0,047580 0,860007 0,001183

1483 A-75X6 Beam CB14OT 0,908534 0,211617 0,303369 0,393549

256 H-200X200 Beam CB2T 0,903900 0,046547 0,856190 0,001163

1499 A-75X6 Beam CB14OT 0,901629 0,195460 0,294025 0,412145

426 C-150+A-90 Beam CB1OT 0,897453 0,047167 0,332158 0,518128

55 H-200X200 Column CB2T 0,896269 0,674066 0,220158 0,002045

1454 A-75X6 Beam CB14OT 0,894490 0,121424 0,216681 0,556385

1462 A-75X6 Beam CB1OT 0,892025 0,127468 0,236725 0,527831

222 H-200X200 Beam CB3O 0,891576 0,046060 0,844568 0,000948

413 C-150+A-90 Beam CB1OT 0,891378 0,045020 0,331550 0,514807

2 H-200X200 Column CB15OT 0,891066 0,499677 0,261598 0,129791

281 H-200X200 Beam CB3O 0,887922 0,043468 0,843420 0,001034

1430 A-75X6 Beam CB16OT 0,887220 0,102739 0,223223 0,561258

1489 A-75X6 Beam CB14OT 0,877898 0,107826 0,246853 0,523218

877 2A-75X9 Brace CB1OT 0,875967 0,288793 0,184038 0,403136

59 H-200X200 Column CB16OT 0,875616 0,461270 0,245492 0,168855

428 C-150+A-90 Beam CB1OT 0,872844 0,030797 0,347071 0,494976

Steel Structural Calculation Report

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