Session 8: SASSI Approach to Incoherency(Simulation and Algebraic Sum Methods)

SShort4:15 - 4:45

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! SASSI Incoherency Approaches

" There are four methods for considering incoherentground motion in SSI analyses by SASSI

- SASSI-SRSS

- EPRI-INCOH

- SASSI Simulation- SASSI-AS

" Treatment of the spatial modes distinguishes thesemethods

" SASSI Simulation and SASSI-AS are implemented inACS SASSI, a commercially available version of theprogram (Dan Ghiocel, GP Technologies, Inc.)

2r .......

1

I SASSI -Simulation (Randomization)

" Perform Monte Carlo simulations varying the randomphase 0 for each spatial mode

- {Ug'} = [A(Io)W] [X('o)] {lo(o)} U0 (Co)* Loop on number of simulations (5, 10, 15, 20)

- Loop on no. of SASSI solution frequencies (10s to100s)

- Randomly sample 0 for each spatial mode• At each SASSI solution frequency, form {Ug,}* Numerical techniques for smoothing & phase adjustment" Calculate SSI response for the simulation (ISRS)

" Calculate the mean of the responses

3 .. u. - 3

I SASSI Simulation Individual Results

Foundotion Z Repons du to Z Input

Motion by SASS'-SrnWultions

1 4

0.4

02

4 C-F=Iel I 'iV Ok ..~P ft....,t *)fl Ok Aa "Un

2

SASSI Simulation Mean Results

Foundation Z Response due to Z Input Motlon by SASSI-SImulItions

12.

n2•

5 rý-f=i~i I T-ýX,,- AI~4~Od

ISASSI Simulation Individual Results

Nods 229, CIS Outfigg.r Z Response due. to Z Inpu.t Notion by SASSI-Siomolotions

II

yrtlooncy (00)

~I~I2I I6

3

I SASSI Simulation Mean Results

Nods 229, CIS Outdigger R..opons. due to Z Input Motion by SASIS"Imnlations

I

10Freepn•/jz

E~I2I ~7

I SASSI-Simulation Analysis Considerations

" Selection of coherency function (1 through 5)" Specification of the number of spatial modes (no

reason to use less than all modes for this approach)" Specification of random seeds and range for spatial

mode phasing* Selection of transfer function smoothing parameter* Decide on number of simulations* Compute the mean of the response quantities of

interest

0006~~~~mr-a j:XbP.0,n0- -noo..--a -1-2

4

SASSI - AS (Algebraic Sum)

• Equivalent to one simulation of SASSI - Simulation with:- Phase angle 0 = 0 for each spatial mode

* {U9,} = [W(O)] [X(cO)I {r0(O)=1} U0(o0)" Numerical techniques for smoothing & phase adjustment" All spatial modes included" SSI response calculated directly

*X0otfld, tan. W~I o.*cn ,.

9 ~=I-E~I ooto

SASSI-AS Analysis Considerations

" Selection of coherency function (1 through 5)" Specification of the number of spatial modes (no

reason to use less than all modes for this approach)" Choice of deterministic spatial mode phasing" Selection of transfer function smoothing parameter

10 ' R nTU"

5

I ACS SASSI Numerical Techniques forIncoherency Analyses

- Numerical techniques to assure the proper relationshipof transfer function frequency to frequency- Smoothing and interpolation - using the Parzen

windowing technique

- Response phasing adjusted by limiting to range of -n/2 to +n/2 to produce higher energy response timehistories

Transfer Function Smoothing

NO& r In.YZI•NF -e8

SpuJe~us peaks usMi the oingal SASSI* unteqxiatan for 201 selected frequencies.

These qxinous peaks were not rewvered,4 ~where we selected a larger nurnber of

/ t : f/ nluencies; weconsidered 201, 224,493

10 M

2-l•2.....

6

I Phase Adjustment

I, Node 229, computed 6 dof ITF Rosette (complex plane plots)at 20Hz for 20 Z-dsaking Random Samples

10-•7y

"1 51 -5z 0 y 0

0-

SYPhMs adjustnmet tnIftthe relative phase angle

GY (avoid cancabg sifads).

-105 0 5 10 Is

I Effect of Phase Adjustment

5% D-.p~d SASM Mo d. 145 ISCV Ouftn). Y-0*.MM X4%0",APO.Abuv"Ww"..

S

I Ma

a-r-rail I-14

7

I Effect of Phase Adjustment

S. OWW M A N, 145 (.&M Y O• W.tI Y-eo,.. Z4-ih.M4100 ,"lMO.MiM IAO"d

U8

a, 10

15 =I-I- I l~EO I~

Validation

• SASSI Simulation and SASSI-AS have been validatedfor use by:- Comparison of results with other SASSI and CLASSI

methods for a validation problem- Comparison to Mita and Luco, 1986 published results

16 =-.ri I2

8

I Parameters of the Validation Problem

" Coherency functions - NAA (2005, 2006)" Free-field ground motion defined by acceleration time

histories matching site specific spectra for rock site(horizontal and vertical)

" Rock site profile

* Foundation is square - 150 ft on a side - 15 ft thick withmass properties

• Structure model based, in part, on an advanced reactorstructure stick model with eccentricities (160 modes)

" In-Structure Response Spectra (ISRS) (5% damped)

.. 0. 17 C=IýI2 I

I Coherency Function for Horizontal GroundMotion (NAA 2005,2006)

Horizontal Coherency as a Function of Frequency & Separation Distance

I1000

0,800

I 0,400

c 0400

0,00.0

0 5 10 15 20 25 30 35 40 45 50

Frequency (Hz)

0 meters - 0.5 meter - 1 meter - 5 meters - 10 meters - 25meters m eters

r _CC111 .18.........

9

I Rock Site ProfileShear Wave Velocities vs. Depth

° L Rock

2 30_

.. ,..fl 0. 0MI3.... EPI21 .......

10

I Site-Specific Response Spectra forRock Site at Ground Surface (Depth O-ft)

RG 160 H ...... t4 (ZPA.3g- - RG 1.60 v1r&Cl (ZPA-0.3g)

0.2 0001 -441

F•oq.on, ,H

210.1 10. . IN

J°,,! ,a-ra,

I Computed andfor Rock SiteTarget Response Spectra

5% Damped Free Field CEUS Rock Motion

2.0

2..

IA-

CA

0.2-

0.1 10 IN

Fqýc.y (Wo)

I -Hak-At I - HooIý 2 VellI - HwiMalbh Tbve Vertica Tau [

m f - eI I E i-Z!.122

11

I Structural Model Characteristics

• Advanced reactor structure stick model witheccentricities- 160 fixed-base modes model the dynamic characteristics of the

structure- Frequencies 3.0 Hz - 141 Hz

- Total mass (x = 92.7%, y = 92.5%, z = 93.1%)

" Three sticks are coupled at various locations - modesare coupled- ASB-3.2 Hz; SCV-5.5 Hz;CIS-13.3 Hz fixed base

* Relative mass distribution- ASB - 86%- CIS-11%- SCV-3%

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12

! Validation by Comparison of CLASSI-SASSI Methods

" CLASSlinco- Deterministic phasing

" CLASSlinco-SRSS- Structure response to each foundation input motion combined by

SRSS" SASSI-Simulation (D. Ghiocel methodology)

- Spatial modes assigned random phasing- Mean of structural response to spatial modes computed

* SASSI-SRSS (F. Ostadan)- Structural responses to each spatial mode are combined by

SRSS" SASSI-AS (D. Ghiocel methodology)

- Linear combination (algebraic sum) of spatial modes used tocompute structural response

... .. ..... .•,--.... ~ ~~25 I- ',,..,,

Results for Comparison

* Calculate three directions of seismic input and combinethe results as in the seismic design/qualification process

• Compare response spectra as calculated

- Coherent (light blue)- CLASSlinco (dark blue)

- CLASSIinco-SRSS (green)- SASSI-SRSS (yellow)- SASSI-Simulation mean (black)

- SASSI-AS (red)• Response comparisons for each direction of seismic

input separately are also discussed

26 I PIPU:,

13

I Foundation Response Comparisons

" Translations at the center of the foundation

- Incoherent response significantly less than coherentresponse

- Responses calculated by all methods are in very goodagreement

" Rotations as measured by translations on the peripheryof the foundation- Little or no reduction due to incoherency compared to

coherent response- Responses calculated by all methods are in good

agreement

27 aI-12I

I Center of Foundation Response - X- DirectionCoherent and IncoherentAll Input Directions Combined

Fdn-x Incoherent respons due to combined Input

F1quo AN AM

21 -18, - SSlSS

12 • •SASl S~ulaJ Mea

4it .• r

2O

o9.

os-- 1

o; 1.

ospk

o28

14

I Center of Foundation Response - Z- DirectionCoherent and IncoherentAll Input Directions Combined

Fdn-o Inloherenl response due to combined input

14

13 NNWl RS

100 h0

o29

I Edge of Foundation Response YY - RotationCoherent and IncoherentAll Input Directions Combined

Fdn-yy Incohernt .ot.tVon .espo-- * 75 feet due to om.bined input

12

10 lE OI• S ,',

Do

801

10 iFnýz~y( H)

15

I Edge of Foundation Response ZZ - RotationCoherent and IncoherentAll Input Directions Combined

Fdn, inco~h.-. ot~tIon mson 75 k~t don, to ooInbined Input

1I :

I~I2I I31

I Top of Shield Building -Outrigger (Node118- 75 ft.)

" Incoherent response significantly less than coherentresponse- Horizontal - frequencies greater than 12 Hz up to 30

Hz (less reductions at ZPA)- Vertical - greater than 10 Hz- Outrigger reductions somewhat less than on

centerline• Responses calculated by all methods are in goodagreement - generally within 10%

" Small increases in incoherent response over coherentresponse at peak spectral frequencies less than 10 Hzare observed - induced rotations effects

16

I Top of Shield Building Outrigger (Node 118) - X- DirectionCoherent and IncoherentAll Input Directions Combined

Nod. 118-ASB -.. po-.. d-e to combi.ed input

50 -ftA 1-RS

ýRS-

.40,

XMs

0 0nn71

10o'F ý (.) H:

331-1 -• 1•• •,i.'

Top of Shield Building Outrigger (Node 118) - Z- DirectionCoherent and IncoherentAll Input Directions Combined

Nod. 118-MB- 0 response due to ofmbined input

14

13

12

11

10

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Top of Containment Internal Structure (CIS) -Outrigger (Node 229 - 75 ft.)

* Incoherent response significantly less than coherentresponse for frequencies greater than about 12 Hz -some reductions greater than 50%

" For this high frequency structure, responses calculatedby all methods are in very good agreement - generallywithin 10%

*~~En~35 r-b, r ef 35i

I Top of CIS Outrigger (Node 229) - X- DirectionCoherent and IncoherentAll Input Directions Combined

Node 229,CIS x rspons du. to ýooblnad input

14 C• 1

1(04

2ýW

^3

18

I Top of CIS Outrigger (Node 229) - Y- DirectionCoherent and IncoherentAll Input Directions Combined

Node 229-CIS y respoase due to on ••,bId input

40 'I i 3

WtS C•mSRSS 71

337

Top of CIS Outrigger (Node 229) - Z- DirectionCoherent and IncoherentAll Input Directions Combined

Node 229-CIS z response due to 0omrbinod input

ýsAl Sa•o s~

100

FII- )

38*

19

I Top of Steel Containment Vessel (SCV) -Outrigger (Node 145 - 65 ft.)

• Incoherent response significantly less than coherentresponse- Horizontal - frequencies greater than 12 Hz (less

reductions at ZPA)- Vertical - very significant reductions for frequencies

greater than 10 Hz

" Responses calculated by all methods are in very goodagreement - generally within 10%

- M9~639 ar-rim

I Top of SCV Centerline (Node 145) - X- DirectionCoherent and IncoherentAll Input Directions Combined

Nod. 145-ICy x rmponim due to ombined input

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-C.Sun~r-SýS

SO5 SASSI-SRS

,

15ý

5.0

205

o100F.1O-" (ft)

Ant.., nv ... 40 f 2 I

20

I Top of SCV Centerline (Node 145) - Z - DirectionCoherent and IncoherentAll Input Directions Combined

Node 145-SCV z response due to co-bined Input

14

F• qc1ya(0t

SM UO

10 1Fst

41f-IaI Z

I Individual Excitation Directions Independently

" Shows differences of CLASSlinco & SASSI-AS results fromthat of other methods

* Containment internal structure (CIS) outrigger (Node229) vertical response (z) is an example

OW O.O~ 00O0000 0O~ ~42 ~ ~ 2

21

I o fCSOtigr(Nd 2)-Z ieto

T op of CIS Outrigger (Node 229) - Z- DirectionIncoherent - X Input

Node 229-ClS response due to x input

10 -CLOSSI~nU,-R

9 SASSl-S, SRSC_SASS: S-umonea

-- 8 m SASSI-AS

G,.

3,3

I Top of CIS Outrigger (Node 229) - Z- DirectionIncoherent - Y Input

Node 229-CIS z -pone due to y input

10

I

j3

10Fm Y(141)

,w

44ra II 2I EI -l

22

I Top of CIS Outrigger (Node 229) - Z- DirectionIncoherent - Z Input

Node Z29-CIS. Z Mponoo due to z input

91-C SJ -SRSSwSA l-SP.$

'0 4

45=F-,-

I Top of CIS Outrigger (Node 229) - Z- DirectionCoherent and IncoherentAll Input Directions Combined

Node 229-CIS z response due to combinod input

FS=00 o.'o M-25 ýS&S-AS

ii

Is

F -mu~ (W•)

23

I Comparison with Published Results

Mita & Luco, 1986 X3

- 40 m high, 10 m radiuscylindrical structurerepresented by stickmodel X2

- Foundation has 10 m H

radius on 400 m/shalfspace

- Transfer functions &H

evaluated at base centerand edge and top centerand edge

OmS~,tI'fld, St~. W~ Mfl47 ~f I S*~ltJ

I Base Center Horizontal Response toHorizontal Input

It

I~I2I48

24

Base Center Vertical Response to VerticalInput

0 MS.~~PR.d. tnh. Mt,~0 AAA~ 49

I Top Edge Vertical Response to VerticalInput

----a. -'. i ------4 -

ta.P. ~

~ Tnffl

I~ff2I I5'50

25