Base_ring_analysis.pdf

PV Elite 2010 Licensee: L&T - Chiyoda Limited FileName : P210-T-1170_Operating_Rev_0----------------------Basering Calculations : Step: 19 3:34p Aug 12,2011

Skirt Analysis Learning

Reference : 1.Brownell & young 2.Mygesy Legend

: Pink text & red colour block are added reference text Other text are pv-elite output

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Skirt Data : Skirt Skirt Skirt Skirt Skirt

Outside Diameter at Base Thickness Internal Corrosion Allowance External Corrosion Allowance Material

Basering Input:

SOD STHK SCA

3509.9495 40.0000 0.0000 1.5000 SA-283 C

mm. mm. mm. mm.

Type of Geometry: Continuous Top Ring W/Gussets

Thickness of Basering Design Temperature of the Basering Basering Matl Basering Operating All. Stress Basering Yield Stress Inside Diameter of Basering Outside Diameter of Basering Nominal Diameter of Bolts Bolt Corrosion Allowance Root Area of a Single Bolt Bolt Material Bolt Operating Allowable Stress Number of Bolts Diameter of Bolt Circle Ultimate Comp. Strength of Concrete Allowable Comp. Strength of Concrete Modular ratio Steel/Concrete

TBA

BASOPE DI DOU BND BCA Area SA RN DC

38.0000 38.00 SA-283 C 1103.82 2108.22 3230.0000 3910.0000 64.0000 0.0000 2857.5701 IS 2062 GR.B 1345.00 28 3720.0000

mm. C KG/CM2 KG/CM2 mm. mm. mm. mm. sq.mm. KG/CM2 mm.

FPC FC

255.0 91.0 9.833

KG/CM2 KG/CM2

Thickness of Gusset Plates TGA Width of Gussets at Top Plate TWDT Width of Gussets at Base Plate BWDT Gusset Plate Elastic Modulus E Gusset Plate Yield Stress SY Height of Gussets HG Distance between Gussets RG Dist. from Bolt Center to Gusset (Rg/2) CG Number of Gussets per bolt NG

20.0000 200.0000 200.0000 2038900.0 2108.2 216.0000 145.0000 72.5000 2

mm. mm. mm. KG/CM2 KG/CM2 mm. mm. mm.

Thickness of Top Plate or Ring Radial Width of the Top Plate Anchor Bolt Hole Dia. in Top Plate

TTA TOPWTH BHOLE

46.0000 200.0000 69.0000

mm. mm. mm.

CA

0.0000

mm.

DW ROW TW EQMOM WIMOM Vormom

267875.7 277364.6 648510.1 348345.5 1246306.2 126741.5

KG KG KG KG-M KG-M KG-M

[EarthQuake Case] [WindLoad Case] TM ppl

138386.2 138386.2 561999.4 100.0

KG-M KG-M KG-M

External Corrosion Allowance Dead Weight of Vessel Operating Weight of Vessel Test Weight of Vessel Earthquake Moment on Basering Wind Moment on Basering Vortex Shedding Moment on Basering User Moment at the Base User Moment at the Base Test Moment on Basering Percent Bolt Preload

Use AISC A5.2 Increase in Fc and Bolt Stress Use Allowable Weld Stress per AISC J2.5 Factor for Increase of Allowables

Fact

No No 1.0000

(UEQMOM) (UWIMOM)

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Results for Brownell and Young Basering Analysis : Analyze Option Note: This analysis is based on Neutral Axis shift method for Steel on Concrete (or a material with significantly different Young's modulus).

PV Elite has

2 different design methods for computing the required thickness of Basering supports.

1: The simplified method will design thicker basering The approximate method simply calculates the compressive load on the concrete assuming that the neutral axis for the vessel is at the centerline. 2: The Neutral Axis Shift Method will design thinner basering when a steel skirt and base ring are supported on a concrete foundation, the behavior of the foundation is similar to that of a reinforced concrete beam. If there is a net bending moment on the foundation, then the force upward on the bolts must be balanced by the force downward on the concrete. But because these two materials have different modulas of elasticity, and because the strain in the concrete cross section must be equal to the strain in the base ring at any specific location, then the neutral axis of the combined bolt/concrete cross section will be shifted in the direction of the concrete. For baserings that are located on a steel substructure the recommendation is to use the simplified method. Otherwise for the traditional basering on concrete use either method. Governing Bolt Load Condition, Wind + Dead Weight Condition: Area Available in one Bolt Abss : 2857.5701 Area Available in all the Bolts Abss * RN : 80011.9609

sq.mm. sq.mm.

Step -1 Find out factor k Trial# 2 4 6 8 10 11

k 0.180 0.315 0.326 0.318 0.320 0.320

knew 0.270 0.337 0.321 0.319 0.320 0.319

Cc 1.153 1.549 1.579 1.557 1.562 1.562

Ct 2.705 2.409 2.385 2.403 2.399 2.399

z 0.463 0.434 0.432 0.434 0.433 0.433

j 0.774 0.782 0.782 0.782 0.782 0.782

Ft 320727.2 327373.8 328032.6 327537.1 327660.2 327639.6

Fc 91252.3 92282.7 92384.8 92308.0 92327.1 92323.9

fs = maximum induced tensile stress in in anchor bolts at BCD fc = maximum induced compressive stress in concrete at BCD on downward side in PSI n = Es / Ec = ration of modulas of elasticity of steel to concrete By itration method Initially Compressive stress on concrete at bolt circle dia. is assumed & fs is taken as bolt allowable tensile stress

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Based on k value Cc,Ct,z,j is found from brownell & young

Based on above factors & Eq. 10.24 & 10 .27 we have to find tensile force Ft & compressive force Fc

Step – 2 Tensile stress in bolt The Actual Stress in a Single Bolt [Sbolt]: = 2 * Ft / ( T1 * Dc * Ct ) = 2 * 327639.6 / ( 6.846 * 3720.000 * 2.399 ) = 1072.557 KG/CM2 , Should be less than 1345.0 Shall be less than allowable tensile stress of bolt

Thickness of the Band of Bolting Steel [T1] = RN * Bolt Area / ( 3.14159 * Dc ) = 28 * 2857.570 / ( 3.14159 * 3720.000 ) = 6.846 mm. T1 = Area / pi * BCD which is used to find bolt tensile stress

Step-3 Max concrete Bearing stress at the edge of base plate Check the Bearing Stress in the Concrete [fc(max)] = fc`[( 2kd + t3 ) / ( 2kd )] = 330.318[(2*0.320*3720.000+340.000)/(2*0.320*3720.000)] = 58.533 KG/CM2 , Should be less than 91.0 First of all fc(BCD) is found with help of equation no. 10.18

For that we need to find t2 from eq no.10.28

Refer Eq. 10.9

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Than with eq. no. 10.30 is used to find eq. no. 10.30

Step-4 Find out bearing plate thickness Values for table 10.3, l = 200.025 , b = 208.692 , l/b = 0.958473

Maximum Moment per unit width [Mmax]: = Max( Mx, My ) = Max( 2345.892 , 3101.317 ) = 3101.317 KG For finding Mx & My take fc = fcmax in kg/mm2

Reqd Thickness of Basering, Brownell & Young Method [T]: = ( 6 * Mmax / fallow ) ½ + Ca = ( 6 * 3101.317 / 1391.4 ) ½ + 0.000 = 36.573 mm.

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Step- 5 Find out compression plate thickness Nomenclature: a P l g1 g2 g Fb

= = = = = =

( Dc-Ds )/2 Sa * Abss Avgwdt Gamma 1 Gamma 2 Flat distance / 2

Skirt Distance to Bolt Circle Maximum Load on one Bolt Average Gusset Width Constant Term f( b/l ) Constant Term f( b/l ) Nut 1/2 Dimension (from Tema) Allowable Bending Stress

Values for table 10.6, l = 200.000 , b = 145.000 , b/l = 0.725000 As b/l (0.725 ) is less than 1, inverting b/l = 1.379 .

Note if value

b/l is coming less than 1.Than invert b/l to l/b & find values of gama 1 & 2

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There are two different equation for Mx & My based on this ratio b/l it will govern b/l = 1 than Mx = My b/l > 1 than My > Mx

b/l < 1 than Mx > My

In this case Mx will govern

Moment Term, based on geometry [Mo]: = P/(4pi) [ 1.3(ln((2lsin(pi*a/l)/(pi*g))) + 1 ] - [ (0.7-g2)P/(4pi) ] = 38424.09 /(4*3.14) [1.3( ln((2*200.000 *SIN(3.14* 105.025 / 200.000 ) (3.14 * 53.975 )) ) + 1] - [(0.7 - 0.085 )* 38424.09 / (4 * 3.14)] = 4576.1523 KG

Required Thickness of Continuous Top Ring [Tc]: = ( 6 * Abs(Mo) / Fb ) ½ + Ca = ( 6 * Abs( 4576.15 ) / 1405.48 ) ½ + 0.0000 = 44.2036 mm.

Bending stress is =

moment / section modulas

Section modulas of compression plate = Tc^2 / 6 Here we have assumed unity width of compression plate Step – 6 Gusset plate thickness

Required Gusset Plate Thickness [tg]: = P / ( Stress Term * l ) + Ca = 38424.09 / ( 1265.5260 * 200.025 ) + 0.000 = 15.182 (not less than 9.525 + 0.000 ) mm.

Stress = load / area Area = length of gusset * thickness of gusset

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Bolt spacing [m]: = pi * Bolt Circle Diameter / number of Bolts = 3.142 * 3720.00 / 28 = 417.383 mm.

Stpe -7 Skirt thickness due to reaction of bolting chair & com pression ring Req. Skirt Thk. to withstand Local Bending, (Brownell and Young) [t]:

2/3

1/3

= 1.76 * ( P*a/( m * ( h + tba ) * 1.5 * Sktope) ) * r + Ca 2/3 1/3 = 1.76*(38424*105.025/(417.38*254.00*1655)) *1754.97 +Ca = 36.985 + 1.500 = 38.485 mm.

Summary of Basering Thickness Calculations Required Basering Thickness (tension) Actual Basering Thickness as entered by user

36.5732 38.0000

mm. from step - 4 mm.

Required Thickness of Chair Cap Actual Top Ring Thickness as entered by user

44.2036 46.0000


Required Gusset thickness, + CA Actual Gusset Thickness as entered by user

15.1823 20.0000


38.4846 40.0000 187.8270

mm. from step - 7 mm. mm.

Required Thickness of Skirt for Local Stress Given Thickness of Skirt Required Gusset Height to meet local stress

Weld Size Calculations per Steel Plate Engineering Data - Vol. 2 Here induced stress = actual load / actual area So first we will find actual load on weld joint than based on allowable shear stress = 0.4 * yield stress Based on actual load & allowable shear stress we will find required weld size.

Compute the Weld load at the Skirt/Base Junction [W] = SkirtStress * ( SkirtThickness - CA ) = 456.404 * ( 40.000 - 1.500 ) = 175.68 KG /mm.

Results for Computed Minimum Basering Weld Size [BWeld] = W / [( 0.4 * Yield ) * 2 * 0.707] = 175 / [( 0.4 * 1912 ) * 2 * 0.707] = 16.245 mm.

Results for Computed Minimum Gusset and Top Plate to Skirt Weld Size Vertical Plate Load [Wv] = Bolt Load / ( Cmwth + 2 * ( Hg + Tta ) ) = 38424.1 / ( 184.150 + 2 * ( 216.000 + 46.000 ) ) = 54.260 KG /mm.

Horizontal Plate Load [Wh] = Bolt Load * e / ( Cmwth * (Hg+Tta) + 0.6667 * (Hg+Tta) ² ) = 38424.1 * 105.025 /(184.150 * (262.000 ) + 0.6667 * (262.000 ) ² ) = 42.926 KG /mm.

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Resultant Weld Load [Wr] = ( Wv² + Wh²)½ = ( 54.26² + 42.93²)½ = 69.187 KG /mm.

Results for Computed Min Gusset and Top Plate to Skirt Weld Size [GsWeld] = Wr / [( 0.4 * Yield ) * 2 * 0.707] = 69.19 / [( 0.4 * 1912 ) * 2 * 0.707] = 6.398 mm.

Results for Computed Minimum Gusset to Top Plate Weld Size Weld Load [Wv] = Bolt Load / ( 2 * TopWth ) = 38424.1 / ( 2 * 200.000 ) = 96.060 KG /mm.

Weld Load [Wh] = Bolt Load * e / ( 2 * Hgt * TopWth ) = 38424.1 * 105.03 / ( 2 * 262.000 * 200.000 ) = 38.507 KG /mm.

Resultant Weld Load [Wr] = ( Wv² + Wh²)½ = ( 96.06² + 38.51²)½ = 103.491 KG /mm.

Results for Computed Min Gusset to Top Plate Weld Size [GtpWeld] = Wr / [( 0.4 * Yield ) * 2 * 0.707] = 103.49 / [( 0.4 * 1912 ) * 2 * 0.707] = 9.570 mm.

Note: The calculated weld sizes need not exceed the component thickness framing into the weld. At the same time, the weld must meet a minimum size specification which is 3/16 in. (4.76 mm) or 1/4 in. (6.35 mm), depending on the component thickness.

Summary of Required Weld Sizes: Required Required Required Required

Basering to Skirt Double Fillet Weld Size Gusset to Skirt Double Fillet Weld Size Top Plate to Skirt Weld Size Gusset to Top Plate Double Fillet Weld Size

PVElite is a registered trademark of COADE, Inc. [2010]

16.2454 6.3978 9.5700 9.5700

mm. mm. mm. mm.

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Base_ring_analysis.pdf

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