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REFERENCE NUMBER :

GE Energy

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DATE

NOM / NAME

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TITRE / TITLE

REDIGE / MADE APPROUVE / APPROVEDVERIFIE / CHECKED

REVISION

INSTRUCTION DE MODIFICATION

Section Doc.N°

SHEET. N°

Ce document, propriété exclusive deGE Energy Products France SNC

est strictement confidentiel. Il ne peutêtre communiqué, copié ou reproduitsans son autorisation écrite préalable

This document, exclusive property ofGE Energy Products France SNC

is strictly confidential. It must not becommunicated, copied or reproducedwithout our previous written consent.

REVISION :

DIRECTORATE GENERAL FOR GAS POWER PLANT PROJECTS

MEGA DEAL PROJECT D

AL HYDARIA POWER PLANTCONTRACT N° 41

[4 x 125 MW]

GRD

None

A4

IM-2006003645

16/05/2006 16/05/2006 16/05/2006

91-457257

MILLER GERARD BRESCIANI DANIEL MIKAELSSON NILS

MIKAELSSON NILSBRESCIANI DANIELMILLER GERARD

CH

EN

UT

BR

IGIT

TEV

ALI

DE

X

E0878 000 --- CG 005

GENERAL DOCUMENTATION-CIVIL GUIDE INTERFACE DOCUMENT

GTG PEDESTAL - CALCULATION CRITERIA FOR GTG PEDESTAL

A

F

14-D

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011-

14:0

9

DT-7C

GE Offic

ial

FOR USE

SECTION 01

GE Energy STANDARD TECHNICAL SPECIFICATION N° 91-457257Products - Europe CALCULATION CRITERIA FOR GT FRAME 9E

AND GENERATOR PEDESTAL Sheet : 2/14

Revision A B C D E F Author SECTION 01Date 30/08/02 10/01/03 27/06/03 04/12/03 22/07/05 16/05/06 Name : P. Lombardelli N° 91-457257

TABLE OF CONTENTS

1- GENERAL .............................................................................................................................................................4

2- SCOPE OF THE ANALYSIS .................................................................................................................................4

3- CODES FOR CALCULATION...............................................................................................................................5

4- GENERAL DATA REGARDING THE ELECTRO-MECHANICAL EQUIPMENTS...............................................5

5- GENERAL DATA REGARDING THE DYNAMIC AND STATIC LOADS .............................................................5

6- DYNAMIC ANALYSIS REGARDING ROTOR UNBALANCING LOADS.............................................................7

7- DYNAMIC RIGIDITY OF THE FOUNDATION AT THE LOCATION OF THE BEARINGS..................................9

8- ANALYSIS OF DYNAMIC SHORT TIME LOADS ................................................................................................9

9- COMBINATION OF LOADS AT THE SERVICEABILITY LIMIT STATE .............................................................10

10- COMBINATION OF LOADS AT THE ULTIMATE LIMIT STATE.......................................................................12

11- MINIMUM REINFORCEMENT RATIO AND GENERAL PRACTICE RULES....................................................14

DT-7CDT-7CDT-7C

SECTION 01




STATE OF MODIFICATIONS

INDEX DATE DESCRIPTION

A 30/08/2002 First issue

B 10/01/2003 Up-dated

C 27/06/2003 Up-dated

D 04/12/2003 §2 revised - seismic and wind loads added

E 22/07/2005 Revised : §2b, §2c, §3a, §4, §5b, §5c, §5d, §6, §6a,§6b, §7, §10a, §10b, §10c, §11c.

F 16/07/2006 Revised : §1, §2b, §4

SECTION 01




1- GENERAL

This specification shall be considered as a guide to allow the foundation designer to establishthe calculation of a gas turbine foundation in accordance with the data provided in the civil worksguide drawings "G.T. FRAME 9E + GENERATOR PEDESTAL" (3 sheets) of GE EnergyProducts - Europe.

Other methods may be used. Nevertheless the criteria specified by GEEPE regarding themaximum displacements and settlements shall be met.

2- SCOPE OF THE ANALYSIS

a) Definition of the type & dimensions of the foundation :

Foundation resting directly on soil, on piles, on elastic blocks or spring boxes etc..., takinginto consideration the soil investigation engineering report giving the characteristics :

- of the soil : friction angle, cohesion, Poisson coefficient soil bearing capacity,total and differential settlement, underground water table level, modulus ofelasticity (static & dynamic), shear modulus etc ...,

- of the piles (when applicable) : allowable and ultimate vertical loads (+ & -), shortand long lasting horizontal strength & moment versus displacement, static anddynamic vertical & horizontal modulus.

b) If the seismic loads are not directly given in the GE Energy Products – Europe loadtable, evaluate the seismic loads for the GT and the Generator using the values asindicated in the load table shown in the GE Energy Products – Europe guide drawings.This seismic load evaluation shall be in accordance with the specified contractual seismiccode.

c) Evaluate the wind loads for the GT and the Generator using the geometry and center ofgravity for the various equipment, as per GE Energy Products – Europe guidedrawings. This wind load evaluation shall be in accordance with the specified contractualwind load code. Wind loads are not considered as acting on the GT or Generator whenthe equipment is protected by a weather/acoustical protection enclosure foundedseparately around the GTG pedestal.

d) Verify the structural global stability, considering the following criteria :

- Stability against overturning under accidental loads (loss of buckets or short circuit orfaulty synchronisation)

- Stability against uplift under the service loads- Check of the foundation mat under service and ultimate stresses- Static rigidity of the foundation- Dynamic rigidity of the foundation

e) Determination of the reinforcement bars taking into consideration :

- The stresses due to bending moments, torques, shear and compression forces- The minimum reinforcement ratio,- The standard practice rules that are not mentioned in this specification.

SECTION 01




3- CODES FOR CALCULATION.

3-a. Dynamic analysisThe designer has to take into account the dynamic loads provided in the loads table specified inGE Energy Products – Europe guide drawings "G.T. FRAME 9E + GENERATOR PEDESTAL"and apply them as later herein described.

3-b. Static analysisThe code used shall enable the designer to calculate and check the results according to theserviceability limit state and the ultimate limit state.

4- GENERAL DATA REGARDING THE ELECTRO-MECHANICAL EQUIPMENTSTurbine, compressor and transmission

The speed of the turbine rotor is 3 000 rpm.

The characteristics of the turbine, compressor and transmission components are specified in theGE Energy Products – Europe guide drawings "G.T. 9Eev + GENERATOR PEDESTAL" (weight,centerline, center of gravity, main dimensions… ).

Generator

The speed of the generator is 3 000 rpm.

The characteristics of the generator are specified in the GE Energy Products – Europe guidedrawings "G.T. 9Eev + GENERATOR PEDESTAL" (weight, centerline, center of gravity, maindimensions… ).

Temperature of the air at the surface of the concrete

For the design of the pedestal, the following temperatures of the air at the surface of the concreteshall be taken into consideration :

- Auxiliaries compartment and generator areas : 60°C / 140°F,

- Turbine and exhaust compartment areas : 90°C / 194°F (Insulation shall be installed andembedded on the pedestal under the exhaust duct. (Not supplied by GE Energy Products –Europe).

5- GENERAL DATA REGARDING THE DYNAMIC AND STATIC LOADS

5-a. Long-time static loadsThe calculation of stresses and displacements due to the static loads is carried out by consideringthe long-term yield modulus of the concrete and static modulus of elasticity of the soil.

The loads to consider are the following :

- Dead loads,

- Nominal torque,

- Exhaust gas back pressure,

- Thermal expansion.

The identified thermal friction loads are the maximum values for the given support pads,and may occur in either the X or Y direction, or in any non-orthogonal horizontal direction.The resultant thermal friction load will never exceed in magnitude the maximum thermalfriction load in the X or Z direction. The actual operational thermal friction load takencollectively at all support locations will not impose a net resultant force on the foundation.

SECTION 01




The designer shall consider the loads with negative or positive signs so that the resultant ofall forces due to the expansion reaches the value of zero.

The values, direction and application points of these loads are specified in civil works guide drawings.

5-b. Short-time static loadsThe calculation of stresses and displacements due to these static loads is carried out byconsidering the short term yield modulus of concrete and the static yield modulus of the soil.


- Loads applied during erection or maintenance phases,

- Loads due to wind along X and Y directions,

- Seismic loads, seism acting along X :

To be considered : horizontal and vertical components due to seismic horizontal forces.Note : Horizontal loads are applied both to the fixed and guide points. Vertical loads areapplied on each symmetrical couple of points, referred to longitudinal Y axis, with oppositesigns.

- Seismic loads, seism acting along Y :

To be considered : horizontal and vertical components of the seismic forces.Note : Horizontal loads are applied to the fixed points. Vertical loads may be ignored(covered by seism acting along X).

5-c. Long-time dynamic loads (unbalancing loads)The calculation of stresses and displacements due to these dynamic loads is carried out byconsidering the short-term elastic modulus of the concrete and dynamic modulus of the soil ordynamic stiffness of the piles.


- Loads due to turbine rotor unbalancing loads,

- Loads due to generator rotor unbalancing loads,

Note that these two loads can act simultaneously in the same direction.

5-d. Short-time dynamic loadsCalculation of forces and displacements due to these dynamic loads shall be carried out by takinginto consideration the short-term elastic modulus of the concrete and the dynamic modulus of thesoil or dynamic stiffness of the piles.


- Turbine or compressor rotor buckets loss,

- Generator fan blade loss, if any in loads table,

- Generator electrical short-circuit or faulty synchronization.

Depending on the generator design one of these situations (electrical short-circuit or faultysynchronization) shall be consider. Only the worst situation is indicated in loads table anduse for the foundation design.

SECTION 01




6- DYNAMIC ANALYSIS REGARDING ROTOR UNBALANCING LOADS

The designer shall carry out a dynamic analysis in order to determine the Fundamental andHarmonic modes along the following input loading directions :

- vertically (along OZ)- horizontally (along OX)

For each frequency that have a significant mass participation within the resonance range, as definedin the paragraph 6-b, the designer shall determine the equivalent static loads as defined in theparagraph 6-d, and calculate, the corresponding displacement at the top level of the foundation.The designer shall ensure that for the worst load combination, the displacements are lower than thehere after limit values :

- in GT area : 80 x 10-6 m or 3 150 x 10-6 in.- in generator area : 53 x 10-6 m or 2 087 x 10-6 in.

These values shall be considered zero to peak.If this condition is not fulfilled, the designer shall revise his design in order to meet the requiredvalues.

6-a. Number of modes to be determinedThe designer shall establish a calculation model of the system machine/foundation/soil for whichhe shall determine all the fundamental modes of vibration (i.e. first order natural frequencies) andeach harmonic (i.e. higher order natural frequencies), all with calculated mass participation.

The natural frequencies and the associated modes shall be calculated in ascending order.

The number of natural frequencies and modes shall be selected so that the highest frequencyconsidered is at least 1.25 times the service frequency of the turbine, i.e., with n = 3 000 rpm :

Hz62.5060

3000 x1.25 =

6-b. Range of frequencies for which a dynamic calculation of displacements has to becarried outFor each fundamental mode of vibration (i.e. first order natural frequencies) included in the interval[0.8 n to 1.25 n] and each harmonic (i.e. higher order natural frequencies) included in the interval[0.9 n to 1.1 n] having a significant mass participation, or the modes or harmonics nearest to theseintervals with a significant mass participation, the designer shall calculate the correspondingdisplacements at the top level of the foundation.

6-c. Determination of the dynamic magnification coefficient used at resonanceWith reference to fig. 1, the dynamic magnification coefficient at resonance represents the ratio ofthe maximum dynamic displacement and the static displacement under the same loads.

Considering :

ξ : Total damping machine & foundation + interaction foundation/soil or piles/soil.

For information, according to DIN 4024 – Part 1 – Chapter 3.1, the damping for machine &foundation may be assumed to be 0.02.

F : functioning frequency.

Fn : natural frequency of the system nearest to the functioning frequency which has a relevantmass participation factor (according to the modal analysis).

SECTION 01




On the diagram of Fig. 1 (From : Bowles – Foundation Analysis & Design) for the assigneddamping ξ and F/Fn ratio, we can determine the requested dynamic magnification coefficient D.

Fig. 1

β : Ratio F/Fn,

ξ : Damping ratio,

D : Dynamic magnification coefficient (= l1 in the hereafter combination formulas).

6-d. Equivalent static loads at resonanceThe equivalent static loads at resonance are equal to the product of the rotor unbalancing loadsmentioned in paragraph 5.c by the dynamic magnification coefficient defined in paragraph 6.c.

SECTION 01




7- DYNAMIC RIGIDITY OF THE FOUNDATION AT THE LOCATION OF THE BEARINGS

In order to check the dynamic rigidity of the foundation, the designer shall apply the followingexcitation loads, in vertical and horizontal directions :

- on each couple of symmetrical turbine or generator bearing support points withreference to longitudinal Y axis :

FT = 5 kN · sin[2p·(nt / 60)t] (transversal)

FV = 5 kN · sin[2p·(nt / 60)t + p/2] (vertical)

nt = turbine or generator speed (in rpm)

The two components, transversal FT and vertical FV, are equivalent to a force vector with theintensity equal to 5 kN, rotating with an angular velocity equal to nt. The forces are appliedseparately for each of the four couple of supports. G2&G4 or G1&G3 or G’&G or F’&F

For each of the four load conditions, maximum transversal and vertical displacements are to becalculated only at the points where the force are applied. For example harmonic loads are appliedon support G2 and G4 and displacements are evaluated at G2 and G4. The designer shall ensurethat the corresponding displacements at the bearings are in accordance with the following criteria :

- horizontal displacement < 2.5 x 10-6 m / 98 x 10-6 in.

- vertical displacement < 2.5 x 10-6 m / 98 x 10-6 in.

- If these conditions are not fulfilled, the designer shall revise his design in order to meetthe above mentioned requirements.

8- ANALYSIS OF DYNAMIC SHORT TIME LOADS

Dynamic magnification coefficient

In the absence of a justified study, the dynamic magnification coefficient l2 may be taken equalto 1.7

Equivalent static loads

The equivalent static loads are equal to the product of the short-time dynamic loads specified inparagraph 5.d, by the dynamic magnification coefficient l2.

nt nt

G2 G4

5 kN 5 kN

transversal

vertical

(or G1)(or G)(or F)

(or G3)(or G’)(or F’)

SECTION 01




9- COMBINATION OF LOADS AT THE SERVICEABILITY LIMIT STATE

9-a. Checking of the punching conditionCombination

[dead loads] + [nominal torque] + [thermal expansion] + l1 [rotor unbalancing loads] + [exhaust gasback pressure] + [wind loads]***

- For shallow foundations, the designer shall make sure that the maximum compressivepressure on the soil , calculated with the above mentioned combination, does notexceed the value of the limit rupture pressure divided by the safety factor of three (3).

- For piled foundations, the designer shall make sure that the maximum compressiveaxial force on the piles , calculated with the above mentioned combination, does notexceed the ultimate compression capacity divided by the safety factor of 2.5 (or differentvalue if specified by the soil specialist, in the geotechnical synthesis report related to theproject).

l1 : dynamic magnification coefficient.

*** : for outdoor equipment only (i.e. no turbine hall or acoustical package).

9-b. Checking of the uplift conditionCombination

[dead loads] + [nominal torque] + [thermal expansion] + l1 [rotor unbalancing loads] + [exhaust gasback pressure] + [wind loads]***

- The designer shall make sure that there is no tensile stress on the soil.

- The designer shall make sure that the maximum tensile axial force on the piles ,calculated with the above mentioned combination, does not exceed the ultimate tensilecapacity divided by the safety factor of 2.5 (or different value if specified by the soilspecialist, in the geothecnical synthesis report related to the project).



9-c. Checking of the static rigidity of the foundationDifferential settlement between the ends of the foundation

Combination

[foundation + equipment dead loads]

For this loads combination, the designer shall check that the differential settlement over the lengthof the foundation does not exceed L/2000; i.e. :

w2 - w1 £ L/2000

L

Initial theoretical position

Position with dead load offoundation and equipment only

W1

W2

SECTION 01




Local distortion

Combination

[nominal torque] + [thermal expansion] + l1 [rotor unbalancing loads] + [exhaust gas backpressure] + [wind loads]***



For this loads combination, the designer shall check that the local distortion due to the settlementdoes not exceed 1/5000, between any two points of the foundation that are load points and supportfor the machinery, wherever is their location; i.e.

Local allowable distortion:w w

L LwL

2 1

2 11 5 0 0 0

-

-= £

DD

/

The calculation shall be carried out considering the short time deformation modulus for the concrete andfor the soil.

L2

L1

position with total dead load of foundation and equipment only

w1 w2 Final position (with load combination defined above)

DL DW

SECTION 01




10- COMBINATION OF LOADS AT THE ULTIMATE LIMIT STATE

10-a. Checking of the punching conditionCombination

i) [dead load] + [thermal expansion] + l2 [turbine rotor unbalancing loads] + [exhaust gas backpressure] + [wind along X]***

ii) [dead load] + [thermal expansion] + l2 [turbine or compressor rotor buckets loss] + [exhaust gasback pressure] + [wind along X]***

iii) [dead load] + [thermal expansion] + l2 [generator electrical short circuit or fault synchronisation]+ [exhaust gas back pressure] + [wind along X]***

iiii) [dead load] + [thermal expansion] + l2 [generator fan blade loss (if any)] + [exhaust gas backpressure] + [wind along X]***

iiiii) [dead load] + [thermal expansion] + [nominal torque] + [seism along X]**

- The designer shall make sure that the maximum compressive pressure on the soil,calculated with the above mentioned combination, does not exceed the value of the limitrupture pressure divided by the safety factor of two (2).

- The designer shall make sure that the maximum compressive axial force on the piles,calculated with the above mentioned combination, does not exceed the ultimatecompression capacity divided by the safety factor of 1.5 (or different value if specifiedby the soil specialist, in the geotechnical synthesis report related to the project).

** : for seismic areas only,


10-b. Checking of the lateral overturning conditionCombination

j) [dead load] + [thermal expansion] + l2 [turbine rotor unbalancing loads] + [exhaust gas backpressure] + [wind along X]***

jj) [dead load] + [thermal expansion] + l2 [turbine or compressor rotor buckets loss] + [exhaust gasback pressure] + [wind along X]***

jjj) [dead load] + [thermal expansion] + l2 [generator electrical short circuit or faultysynchronisation] + [exhaust gas back pressure] + [wind along X]***

jjjj) [dead load] + [thermal expansion] + l2 [generator fan blade loss (if any)] + [exhaust gas backpressure] + [wind along X]***

jjjjj) [dead load] + [thermal expansion] + [nominal torque] + [seism along X]**

The designer shall check that, for the worst combination, the safety factor for lateral overturningwith respect to a longitudinal axis is greater than 1.5 .

** : for seismic areas only,


SECTION 01




10-c. Checking of the reinforced concreteCombination

i) [dead load] + [thermal expansion] + l2 [turbine rotor unbalancing loads] + [exhaust gas backpressure] + [wind along X]***

ii) [dead load] + [thermal expansion] + l2 [turbine or compressor rotor buckets loss] + [exhaust gasback pressure] + [wind along X]***

iii) [dead load] + [thermal expansion] + l2 [generator electrical short circuit or faultysynchronisation] + [exhaust gas back pressure] + [wind along X]***

iiii) [dead load] + [thermal expansion] + l2 [generator fan blade loss (if any)] + [exhaust gas backpressure] + [wind along X]***

iiiii) [dead load] + [thermal expansion] + [nominal torque] + l1 [rotor unbalancing loads] + [exhaustgas back pressure]

iiiiii) [dead load] + [thermal expansion] + [nominal torque] + [wind along X]***

iiiiiii) [dead load] + [thermal expansion] + [nominal torque] + [seism along X]**

The combination factor will be considered according to the applicable ultimate limit state Code.

** : for seismic areas only

*** : for outdoor equipment only (i.e. no turbine hall or acoustical package)

SECTION 01




11- MINIMUM REINFORCEMENT RATIO AND GENERAL PRACTICE RULES

11-a. ConcreteThe characteristic compressive strength of concrete, measured at 28 days, shall not be less than25 Mpa/3 600 psi. for grade 25 concrete with test cubes, or 21 Mpa/3 050 psi for grade 21concrete with cylinders.

11-b. ReinforcementThe concrete cover shall not be not less than 30 mm / 1.2 in.

Longitudinal & transversal reinforcement :

The spacing of the longitudinal and transversal rebars shall not exceed 300 mm / 12 in.

- Reinforcing steel with a minimum yield strength of 400 Mpa / 58 000 psiThe reinforcement to be placed in the foundation shall correspond to the maximum of thefollowing values :

· Reinforcing section determined by detailed analysis/calculation,· Minimum reinforcement ratio according to the specifications of the applicable

Standard.

Mass reinforcement :

The mass rebars shall be placed inside the longitudinal & transversal reinforcements, in the 3directions. The minimum diameter shall be 16mm / 0.63 in, and the maximum spacing 1 000 mm /40 in.

Total minimum reinforcement ratio :

The total reinforcement ratio for the whole foundation (longitudinal, transversal and massreinforcement), determined as specified here above, shall meet at least the requirement of DIN4024 – Part 2 – Article 7.2.

11-c. General practice rulesThe first phase concreting (from lean concrete to RL level) shall be executed in one single andcontinuous operation in order to get a monolithic foundation block on the whole length .

The piers for Gas Turbine and Generator shall be done in a second phase, in a single pour each,after adequate treatment of the horizontal construction joint.

The foundation shall be isolated from other foundations and ground slabs, (construction joints,minimum 20 mm / 0.8 in thick, sealed with suitable mastic, shall be foreseen where needed).

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