ML20063E344

Responds to IE Bulletin 80-11, Masonry Wall Design, Per NRC 820721 Request.Responses to Questions 2,4 & 14 Re Stack Bonding & Modeling Techniques Encl

ML20063E344
Person / Time
Site:	Fort Saint Vrain
Issue date:	08/24/1982
From:	Lee O PUBLIC SERVICE CO. OF COLORADO
To:	Clark R Office of Nuclear Reactor Regulation
References
REF-SSINS-6820 IEB-80-11, P-82-354, NUDOCS 8208300220
Download: ML20063E344 (14)

Text

..

.O PUBLIC SERVICE COMPANY OF COLORADO P.

O. BOX 64O DENVER.

COLORADO 80:.01 OSCAH R. LEE Fort St. Vrain we.......,

Unit No. 1 P-82354

%d&9 Mr. Robert A. Clark, Chief Operating Reactors Branch #3 Division of Licensing Nuclear. Regulatory Commission Washington, DC 20555

SUBJECT:

I&E Bulletin 80-11, Masonry Block Walls

Dear Mr. Clark:

The following infonnation was requested in your letter of July 21, 1982 on the Subject of the IE Bulletin 80-11, Masonry - Block Wall Design:

NRC QUESTION 1

, Indicate Whether the Walls Are Stack Bonded or Running Bonded PSC RESPONSE 1 The masonry block walls at Fort St. Vrain are running bonded.

NRC QUESTION 2 Describe the Assumptions, Modelinj Techniques, and Procedures Used in the Analysis PSC RESPONSE 2 See Attachment 1 he-

/

01 f

8 e

Aoo!!0$80gg.,

J PDR

^

lP182354 Page' 2

-NRC QUESTION.3 4

Indicate-^How Frequency Variations Due to Uncertainties in Mash Waterials and Other Parameters Wri~ Considered PSC' RESPONSE 3

~

Frequency? ' variations due to uncertainties in mass, materials and wall thickness were considered but were found not to be important items. for the analysis. ' This is because PSC was conservative in the values used for these parameters in the analysis.of the block wall.- Also,2since the frequency is a function of the square root of these parameters, any variation in the parameters will result in a smaller variation of the frequency.

NRC QUESTION 4 Using Sample Calcul ations, Show How it Was Determined That Seismic Differential Floor Displacements are Negligible PSC RESPONSE 4 See Attachment 2 NRC QUESTION 5 Provide Damping Values Use in' the Analysis n.

PSC RESPONSE 5

['-

The 3 masonry. block walls were analiz'ed for the-DBE-event using a i ~

' dasping yalue of 5%.

.~

c s-NRChSIION6

s. '

i.,

h Indicate the Boundary Conditions used for Analyzing Masonry Walls and

~

\\ \\ Provide Justification y

3

~P50 RESPONSE 6 e-y y

A; pinnad,- fixcd' or free end-boundary condition was used in the

. wall analysis:, depending upon the individual wall and the

. engineering judgenient of the engineer.

i m

for walls imbedded into concrete. floors, a fixed boundary dondition was used.

For cantilever walls, the top of the wall is

~~

i considered to have a-free boundary.

For walls framing into structural steelsor, concrete, a pinned type boundary condition e was used. These types of boundary conditions can be justified by engineering judgement of the moment. carrying capacity of the

' w ; boundaryi j

s e

,e 3

iM N

[

L i

,L G

L V

.\\j N

4 i

4.

s-

.- s r. "%.

.a w. -

- rha.:. ;<.

L.

a. --.

P-82354 Paga 3 NRC QUESTION 7 Specify Material Types Used_d Mo, Respectively.

for Masonry and Mortar, and Provide Their Compressive Strengths fm an PSC RESPONSE 7 The material types and compressive strengths are as follows:

I.) Masonry:

ASTM 90, Type I units, Grade U-I block, with linear shrinkage of 0.04%

maximum.

Minimum compressive strength of 1350 psi (fm).

II.) Mortar:

Minimum compressive strength = 1200 psi- (Mo).

Materials:

Cement:

Portland cement:

ASTM C150, Type I or II Masonry cement:

ASTM C91, Type II Lime:

Quicklime: ASTM C5 Hydrated Lime: : ASTM C207. Type S Masonry Sand: ' ASTM C144, use natural sand only Mixing Water:

ASTM 270 NRC QUESTION 8 Provide Values of Allowable Shear Stresses in Flexural Members for Cases in Which There is No Shear Reinforcement and for Cases in Which Reinforcement takes Entire Shea_r, PSC RESPONSE 8 The masonry block walls at FSV are unreinforced and an allowable shear stress for the DBE condition of 30.6 psi was used in the analysis.

P-82354 Pag 2 _4 NRC QUESTION 9 Provide Information on Constru'ction Practices and Relevant Quality-Assurance Records to Justify the Use of Allowable Stresses Applicable to the Special Inspection Category.

PSC RESPONSE 9 PSC's position is that Fort St. Vrain being a nuclear generating station and built with detailed procedures, specifications, and construction. drawings, would qualify for the criteria of inspected workmanship.

Upon inspection of all masonry block walls by PSC the workmanship and quality is such that in our judgement the special inspection category applies.

Quality Assurance Records for the Masonry Block Walls at FSV not available.

NRC QUESTION 10 Provide any Increase Factors that May Have Been Used for Allowable Stresses under Abnormal Loading Conditions.

PSC RESPONSE 10 The Allowable concrete masonry stresses were increased by 33% for the DBE event.

NRC QUESTION 11 Provide Information on Loads and Load Combination Factors Were Used in the Analysis of the Masonry BlockYaTis.

~

PSC RESPONSE 11 Live loads were considered for live loads. from equipment, conduit, etc., attached to the walls.

Combination Factor = 1.0 Dead load were considered from the weight of the masonry block walls.

Combination Factor = 1.0 The design basis earthquake seismic loads were included in the analysis Combination Factor = 1.0

P-82354 Paga 5 NRC QUESTION 12 Provide Sample Calculations for Missile Impact (if applicable).

PSC RESPONSE 12 This item is' not applicable at FSV since the walls were not designed nor are they required to provide missile impact.

NRC QUESTION 13 Indicate if Any Non-Linear Technique was used in the Analysis PSC RESPONSE 13 No non-linear techniques were used in the analysis.

NRC QUESTION 14 Provide Details of Wall Modifications with Drawings. Also Provide a Sample Calculation to Illustrate that the Wafis can be Qualified Under Working Stress Design Conditions after Modification PSC RESPONSE 14 See Attachment 3 Should you have any further questions on this subject please call J.

R.

Reesy at (303) 571-6643.

S.incerely, 4

l[

['

O. R. Lee, Vice President Electric Production ORL/ RAG:pa Attachments l

I

(

L

ATTACHMENT 1 Assumptions, Modeling Techniques, and Procedures Used in the FSV Masonry Block Wall Analysis.

INTRODUCTION: The following steps are to be taken when analyzing the masonry block walls based on the prepared sketch:

I.

LOADS:

The masonry block walls shall be analyzed for the DBE event.

The following loads shall be used in the analysis for small pipes and conduits attached to the masonry walls:

Conduit Size (in)

DBF Force (lbs) 3/4" 0 9#

1" $

14 #

1 1/4" 9 19 #

1 1/2" $

25 #

2" 0 40 #

2 1/2" 0 68 #

3" S 130 #

3 1/2" 9 162 #

4" 9 188 #

REFERENCE PSCC. SDC

C. PROCEDURE

S The following weights shall be used for the dead -

weight of the masonry block well:

Wall Size and Type Weight #/Ft 6" Hollow 40 #/ft2 8" Hollow 60 f/ft:

12" Hollow 80 #/ft:

6" Solid 70 f/ft2 8" Solid 93 #/ft2 12" Solid 140 #/ft2 Weights for other items such as tanks and junction boxes attached to.the walls shall be determined by contacting engineering for a case by case determination.

For walls that are inaccessible (NAK) either on one side or both

sides, assume that any attachments to the wall equals 12% of the dead weight of the wall.

This assumption is based on review of walls that are accessible from both sides.

II.

METHOD OF ANALYSIS A.

For walls that span from floor to floor, or from column to co'lumn, assume a simply supported beam model.

For walls that do not span from floor to ceiling, assume a cantilever beam model.

B.

Use the Following Analysis Steps:

1)

From the detailed. sketch of the wall, make an engineering determination of the critical section for analysis, based on the number of attactinents, their location, and penetrations _through the wall.

2)

Detemine the loads for each of the attachments, and determine the beam model to be used.

3)

Determine the unifom load-to be used in the analysis for the dead weight of the wall.

4)

Put the loads on the wall and calculate the reactions, shear and moments.

5)

Determine the equivalent. unifonn load to be used in calculating the natural frequency of the wall.

6)

Calculate the natural frequency of the wall using the following fonnulas:

f= 9.877 EA Pin-pin beam 2 TT wl4 f= 3.52 EIS Cantilever beam 4

2Tr wl where:

E = 1,000,000 psi I = Moment of Inertia of Wall Cross Section, in.4 g = 386.4 in/sece w = Uniform Load f/in y

L = Beam Length (in) w TT = Pi = 3.14159

=

f = Natural Frequency, cps

REFERENCE:

FORMULAS FOR STRESS & STRAIN, BY R.J. R0 ARK 7)

Use the floor response spectra for the floor on which the wall is located or for the floor directly above the-wall, whatever response spectra yields the largest f

seismic g factor. Assume a damping value o' 5% in the analysis.

8)

Multiply - the maximum shear and moment by the g factor to obtain the seismic shear and seismic moment.

9)

Mul tiply the seismic. moment and _ shear by 1.05 to account for the contribution of higher mode affects of the wall vibration.

This.is an assumption resulting from an owner's meeting on Masonry Block Walls.

10)

If the analysis assumes a vertical span beam, check the following formula:

M - 0.75 P dE Ft.

T I

where:

M = Seismic Moment S = Section Modulus of Wall P = Vertical Load on Wall Area A = Cross Sectional Area of Wall Ft= Allowable Masonry Tension Stress 11)

If the analysis assumes a horizontal span beam use the dur-a-wall capacity to resist the seimic moment..

The dur-a-wall moment capacity for the various wall sizes are as follows:

Wall Thickness DBE Moment Capacity 6"

278 FT-f 8"

413 FT-f 12" 690 FT-f

Reference:

Reinforced Masonry Engineering Handbook.

12) Check the shear stress in the masonry using the following formula:

V 4 Fv X~

where:

V = Seismic Shear A = Cross Sectional Area of Wall Fv = Allowable Shear Stress

13) Check the stress around opening in the masonry walls and use a maximum stress concentration factor of 3.0.

Most existing openings for duct work have reinforced lintels.

III.

-ALLOWABLE STRESSES The following allowable stresses shall be. used in the analysis of the masonry block walls:

Reference ACI 531.72.

i Tension Normal to Bed Joints.

21.3 psi = Ft Tension Parallel to the Bed Joints 42.6 psi =~Ft-Allowable Shear Stress 30.6 psi = Fv This assumes inspected workmanship of the Masonry Block -

Wall s.

IV.

DESIGN OF THE BAR STRAPS Use the following formula to design the steel required for the bar straps:

As = 12 Mu fy t Where:

As = Required Area of Steel, In2 Mu = Seismic Moment, FT-f fy = Yield Stress of Steel = 36,000 psi t = Wall Thickness Use 5/8" A Bar Stock to thru bolt thru the wall to attach the bar straps.

Use a spacing of 36 inches to 40 inches for the bolts.

/?M/;V/'ff47" s~r.cresc

.0//'EdrwrML FZsa <

<:2crAcx6&rorr 8

k eda C'4:>VNofO h/Md4$ A 7*

8

.I J6 l

l

/C'~[

.$~/**

f.***#d/W 7HG" l

I ffdW/s.5/<:53ff

.a(s9 7 &~. Art Sr.f.Aw l

7~~M c44

/ $*

Sc x 0 00/

I I

N s <.*922.

I l

4 fC

=

l i

f

.ser#.*

/'V r ad

.s::= M~7/c24' /

Ne' y

7pvc M 4t.7M/7>"

<:::ta"~

K4xt3

.dr M.s~r u t*+ v 7?r. 4'r Sam AAI* cst

^~4e;&nse

/a

<::~fsc/wd

s.am: wag

~

<::n P' Afa64 S MD 3oM 7w det'fL d

7?rd"

./'7 4 4's m 4*'d.<r2%s.o r,.*4.

rinr.<sr*/* r/e

.d4/W E d 7 n f r +-

THEs6 4'Ex *f2 $

./.c C.

Oo? se~f 6 7~

O.sd

. 4 ~ 4 b s f rs o n *'

/

7a:s 5~ CAM fed THE s<r,# w s'x.*~7 s.< <As4

1. f/d'*k7'

/V' =

8

.,H =

s. Co 7

6. O d /

.,#f'=

7 fff7*

rs. vce

/91<

4:e. dzz.s*

94 4 es~dfcrrs 7.k. 9s

~7 ffr7-

.*' s*

1. #sd #*7'y 7,~+ ddo ss Aso AdoddEM s.<.-/7s+'

5"~f s s / s'/ d

& /'/* ~f.t"'d ** 7"*// 9d fdM *

.t:;;3<.S A Ant'f & d k~73*.

J

_ _ _ _ _ ~ _ _ _

an

__.aa

.2

-%a m

>vs warern-!

et.Z o.sv/.//r y @ 3 2 >~

" 6*". )

77s3;f f P c y S.;v f' k t*

A >P'W.S J 7'7S.i>f 2.// W/ C7 f./-

= 6 **'

7

=

JP'#v74l>.J red.:l>"C'In4,"

.Ji##./ s 15

• F#;V

/fg;s'*"

9/ #s*#'

s.,, 5lP' y

t.// "' B :+e7 2

• 2"'

.5 ;P4'.4.R.aiP#edi>'o

s.~'r 9 " c :P pry

, + J/ o-7 e,. se.p4:e /s c==

pe::>V cr.7 c

> d v/sp' i:>c>.C

.: o c "avcP7

<<<,>c2V'"::P "2/ *'r

(.F #c:;>.5:P

'so' ~r.,, c=>;_9

% v. s. p -

w6s.s 7v.w.trs -7 y

>.ecrssoc;>

>

./.vf.y C7f a MAP /M

/C=C*.y

.r&C" Ji>'J.cv'"

>'> c>74>'

. r'O'

/N.9/f "!

l

/M d28.2 0"*.747"7

• 77FW W. r " J"PC;P

,,SP

r'a'lllP 3;P& fed.'4Ss' 'ClllP' dd J / W Q

• E Y,/

.C39 f CF all' JFt;7' 7 7 6*' W NC>

S 4 7t V O,;Y'

. w,

. y.

--,.s e

Js

--7,-

<co'p,, -

, ef-

=

&c=~ sos.x m-.s;rsr.ts &st:"SVA, -

3 76>r m ces74 '

. -cr' m' e

, r ev.sm.s.x

.s-

.s rsy./.s~

7.r r.< c-

.r7syma77s -

g > =

.s,.

Fav'e:wo n+'y r 737.S;>,*s V d'7 >

/ etsv arts *e 7 Y c'.L s

4 o:y".>V./.<V' 'S. >, e::;;",.6, y, 7 2' 3 FWVP rs' di>6' :39' : d'4"pt!9'ef#/.' 'n>'

i

F&oo&.'r"/<.=

.xs/M.2 gx s. 2-Sir x, cv, c78 e

nV./ s#d';7 776 ***>f tSVi?.$>&Aut;;pc'7 77V*7 J S.594:t

PN./A>'c?O7 77V'f g:;rs.rg,y

, 76'l/ '7.?'

P**'Xp

*' y - c;;p g o,,rw l

Ji Il i

2 Ss I

(!

seer /

s cres

+

l l

z.s

~ -

z7s <><.u:7 d>'c??k,4/ 3k/Flf W. A n

/'

1 m

YS$/

j

.sW#f

.r.w.r:v '

S&C39G?6#2/.p/s?C;*=4/' /*'>'r FM.2/C;7&C";"

f9ff f.f P M ?v W C3"!

s3 tan's;;>'4*7

&c>u+.v n7s--vo-7rs -,-r ma +.s.

e,.x rc>u v7 x>>u.c:;;- 37c>u ;.s-

' nC.,rC>GPJV' WV.sEP *4*%/**

• 5' As*f'

'f,s**

7 7V*'>v

.*1'*;;> c:P7f

.*'t'e>3**C;>ff *Q o

[

d H.,P 4 / H ?siV.f.Z j;*

.or.ercmwa s mex

.e.ewr> w,:r A

• f48*

A 3/8*

.c2s"

7. Sz '

/l v

4*4.

• EM 4'//;"/~

h h

h 1

U

\\Y ffsrs~f m d s;f- /

1V 9'

-rsg sco-pe-t ex '

=

4.s = 324/*

o 1

1 1

<r r

p N* _N

• Sbh/g A

z W

N* f.u2 / 8x $~ES M M fd/7~ 1 2

/ A 3.c 7 4 2 '

f <*WM? ) x 6.S '

v c

~

/gz, n f.eroufx>-

c u c u s r/o v.c

o

.ows-c v. we s nrs wa. 4;wiuox 7d, -

an2 erg 2&

w

,t 4 i

7hy 3.S~2

'rso x

/S2/ < 324 4

=

2/?

32.7 x'

93 1

r 4 =

,. 7 n.a

~se n,

, as s n.

ow,

s. ~ e -- o.27 4* M'd 8 5o m sv6'

M l

ofs,5&c Mas &dN7~ c M A-D27%4c2S' f.,533 f['#

fx4:s A su. M er+r =

3M fr-#

f72/ F7~ 29~

f re 744 =

d OX O. / } %

/OS

/C 2/ AE*

.3*fA.:5' &AC

.,5"/f&~ )A s

k / <>s 7 x x c.c o

sams-wases nm ss.aw OcF7/M&f M MkP Cd M rry & 6/94

.:5~74A?P.S SMMP.S.

A W-C

c. c.

g

=

4;9. 32 9 Av.

(2~ /gg ) 4 _/

A.s-'

&&~r* s ?tG78 A*

=

1 ls*

22, ocuo Ari 4? v B n.

Arr

/4.r-b 42

.;E' '

/

h-

s. 328 < 22 doo x Ao

_f_

.c f'

M' 72, /8 7.or a ^v 4 AS~ M.*

=

7"r.ecroer Monev7-comry os sse sne o.s As

<5" A d A"73G"A?

7&&

Mr.$M Mo &&v 7*

<**>VG~<*<

M f s' 4 r&

MAfe2NAi* Y b

f=

/'O 2/

1. Sps* f ex

=

.=r x s.s-

2. Gunnerson 9 3o PRoPosEO Flx FOR Mo n ENT

c. A cclN G c a.N N E 4 7tolg ( SANTILEVEC)

M.

cHscK PRYINc. AaroH c O 7-F, : 4 "w-fl T AT AN cHoa EoLT S-

=_

8 ~vvall T

118 GAe %

etoa a l 2' Ws.ll T

f).

l 2.

~

T y Hcu Got.7 c

sx s = y4 Angle 3 N

Conc r e.k

• A nc ho c R.

_ul V

Ih3 4 = \\ }4'"

S, '

T M, o

3T-i.2 6 l4 Q

3T -

l?-

Xs.

• 5. o t45 m.

3(H)

Foe 6 ' L v. ll :

E--

2. o M

o. 4 M

=

& c f.2.5 )

1.25 (11)

.I. S n Foe 8 wil 2-

o. 5 H 3

8 Foe 12" w ll:

I2 -

3 II } =

0. p_ M

f. o M IT6 l 2. /

(toaid F,Ild weIl Capaafy

~ Too y a i par y4 mild.

A(700) e ecc #

I torc e 54 oo a z uoE Assun E N.

Prying A ct ex g AncL,r. Psilout Foa.

M=

rd ( G+3.5)

7 2

o. Ios M O

s ma u_:

N 2 ( 9 + 3. 5 )

2-o.os7M 12+ vy ALL :

P '9/

N=

e ( 12 + 7. 5 ')

9 O.O M N 4

'