ML20206T435

From kanterella
Jump to navigation Jump to search
Rev 0 to Procedure SAG-CP.09, Instruction for Reevaluation of Cable Tray Hangers Affected by Longitudinal Tie of Transverse Hangers to Tray
ML20206T435
Person / Time
Site: Comanche Peak  
Issue date: 03/31/1986
From: Sunny Chen
EBASCO SERVICES, INC.
To:
Shared Package
ML20206T195 List:
References
SAG-CP.09, SAG-CP.9, NUDOCS 8610060308
Download: ML20206T435 (7)
v • d • e


Text

.

SAG.CP.09 3/86

'O ERASCO SRVICES INCORPORATED INSTRUCTION FOR REEVALUATION OF CABLE TRAY HANGERS

'AFFECTED BY THE LONGITUDINAL TIE OF TRANSVERSE HANGERS TO THE TRAY FOR COMANCHE PEAK STEAM ELECTRICAL STATION UNIT 2 O

l l

PREPARED I

REVIEWED l

APPROVED l

l PAGES l l REVISION l BY l

BY l

BY l

DATE l AFFECTEDl l

RO lS J Che lR Ale nd lG nakaris l

l l

1 I

I I

I I

I I

I I

I I

I I

I I'

I I

I I

I O

$$kU0ISS$ oIO $5 A

1346m

- - - _. _. =. -_

_ _ - ~ _ _ -

~~

TABLE OF CONTENTS f*ES 1.0 Introduction 1

2.0 Reference Documents 1

3.0 Hanger Reevaluation Guidelines 1

3.1 Identify the Hanger Candidates for Tie 1

3.2 Define Analysis Strings 1

1 3.3 Evaluation of Longitudinal Hanger 3

3.4 Evaluation of the Tied Transverse Hangers 3

3.5 Effective-length Factors K for Buckling Evaluation

,5 3.6 Alternative Analysis Method 5

I i

i j

i i

i i

1 i

e l

1 l

l 1346m

.,......-.?

,...... :_._ _ _,_ a _._, _.,

~n P

1.0 Introduction O-This instruction is prepared to provide guidelines for the design reevaluation of transverse cable tray hangers affected by providing longitudinal ties to the tray for the Comanche Peak Stear. Electric Station (CPSES) Unit 2.

The longitudinal ties of transverse hangers to the tray are used in the design modification to solve the problems caused by K1/r and weak exis bending in the transverse hangers. The reevaluation of the affected hangers shall be in accordance with the Design Criteria in Reference 1.

The general instructions for cable tray hanger analysis documented in Reference 2 shall be followed in addition to the guidelines presented herein. All the terminology used in this document is consistent with those of Reference 2.

2.0 Reference Documents 1.

Seismic Design Criteria for' Cable Tray Hangers for CPSES No. 2, j

Rev. 4 December 4,1985, Ebasco Services Inc.

2.

General Instructions for Cable Tray Hanger Analysis for CPSES No.

i 1 and 2, Rev. 2, December 20, 1985, Ebasco Services Inc.

i 3.0 Hanger Reevaluation Guidelines b

j By adding longitudinal clamps to tie a transverse hanger to the trays, the seismic load in the transverse hanger will decrease since a major portion of seismic load will be transmitted through tray to the next longitudinal hangers which have higher rigidity in longitudinal j

direction. A static equivalent analysis method as presented in Reference 1 can be used in the evaluation of the affected hangers.

j The following are the guidelines for the reeva$uation of hangers by using the static equivalent analysis method.

a f

3.1 Identify the Hanger Candidates for Tie From the hanger span layout, locate those transverse hangers which have problems complying with K1/r or high stresses due to weak axis j

bending and are field verified for the feasibility of providing a tray tie. They are identified as candidates for longitudinal tie to the

+

tray.

j 3.2 Define Analysis Strings Define an analysis string which consists of one longitudinsi hanger and at least one transverse hanger with longitudinal ties. All transverse hangers with longitudinal ties located in one half of the l

longitudinal span on each side of the longitudinal hanger should be included in one string. They should also be included in one string if 1

they.are located at the free end of the tray or the bend of the tray.

For exaspies, see sketches below.

O

1.

a

/

(x TRA AISVERSE WITH TIES (Typ) l[l).

l fil l

l

'i li e rRiv 8

i i

l

~.TRAMSVERSE

[

l

+

l l

n l

l (TY P) -

I I (1).

(

l

-1 1.Lt

'lq LLo -

LON41TUD!NAL 2

. LT4P)

JAMALYSIS STRlWG LLt

..LL2 TIES TIE

' TRANSVERSE I[l (TYP) l cl]I,'(11, I,

l l

i i

p l

5 I

til I

l8 l

8 i

~7ggy '

v 1"w?z lI I II Ill l

l l

/- r I

lil l

Il l

l l

i lij i

l~i.lI i

i q1.CNQlTUDlHAL

, ~,

LLI LL2

~ (TYP)

LLt 10 LLS ANALYSTS STR1NG

~LONQlTUDlWAL (TYP)

TIES TIE TRANEVERSE (TYP)

!I ' fl !

I,1 I Ii l

l t

l l

l ll l

[& l l l

l l l k

, TRAY 7 BEND 1 J I dj

(_j i

' L L2 AM ALYSIS GTRlWG !.

( '

i Q

- -- y 2

....c c

3.3 Evaluation of Longitudinal Hanger b

Dead weight and thermal load -

a.

There is no impact due to the adding of transverse hanger tie, therefore the methodology and instructions in References 1 and 2 can be used.

b.

Seismic load in transverse and vertical directions -

No impact (same as above).

c.

Seismic load in longitudinal direction -

1) In determining the hanger frequency, the appropriate portion of the dead weight of the tied transverse hangers within the analysis string shall be included in the tray weight and lumped at the tray supporting points.

ii) Similarly, the longitudinal seismic load due to cable tray weight (P ) shall also include the weight of tied transverse L

hangers for the static. analysis.

iii) Record the seismic "g" value including the effect of multimode response multiplier for later evaluation of the tied transverse hangers.

iv) Record the hanger longitudinal displacements at the tray supporting points due to the longitudinal seismic load. These displacements will be used later in the separate static evaluation of the tied transverse hangers.

3.4 Evaluation of the Tied Transverse Hangers a.

Dead weight load -

No impact.

b.

Seismic load in transverse and vertical directions -

No impact.

c.

Thernal load -

If the tied transverse hangers are located at the end of the tray or next to the bend of the tray, same procedure in determining the l

thermal load in the longitudinal hanger as presented in Reference 2 can be used.

i d.

Seismic load in longitudinal direction -

'The effects of longitudinal seismic load on the tied transverse

. O support shall include both the displacement effect induced by the longitudinal hanger and the inertial effect at the hanger itself.

Therefore, the superimposed results of the following two load cases shall be used for the seismic load in the longitudinal direction 3

1) Imposed displacement load -

V The displacements at the tray supporting points of the longitudinal hanger obtained in Paragraph 3.3.c.(iv) shall be applied at the corresponding locations in the transverse hanger model as follows:

i W~

XND 2 ARE~THE 1MPOSED- ~

M-

-DlSPLACEMENTS. AT THE TRAY Wo.1 p*

-. -. p AND TRAY No.2 SUPPORT!NQ 7 C.Q'O F POST' ~

LOCATICMS RESPECTIVELY.

~

)..

    • THE LEWQTH OF RtQtD EAR REPRESENTS THE ECCENTRtCITY

' ' ~

~" "

.OF THE LOWQlTUD!WAL LOAD Pt.WITH

._..y_...__

RESPECT _TO.SHE AR. CENTER OFJ1ER.

- S (SEE SWEETS 14 AND 74.1 OF t - - b~ t.- K ATTACHMENT 52 IN REFERENCE 7)

A ' _~~~~ ~ - -

I W **- W = WIDTH OF TRAYS.TO UTILIZE THE

, g2-2 A' SMALLER VALUE T.XISTlWQ MODEL,OF TRAYS CAM BE g

A-THAH THE WIDTH

['"

q USED.

xtstod ~,F--

EAR **

-Risto mars SHEAR CEMTER.

.0F TLER v

ii) Inertial load -

The maximum seisnic "g" value in longitudinal direction obtained in Paragraph 3.3.c.(iii) shall be applied at the tied transverse hanger model with longitudinal restraints at the tray supporting locations as follows:

e

~ C.G OF ROST HOTE:THE MODEL is THE'SAME~As q

THAT FOR THE IMPOSED DISPL ACEMENT LOAD EXCEP.T.THAT

.N THE LONQ1TUDINAL RESTRAINTS

%F ARE PROVLDLD.

i N,

.5h

'.~..

b _...

.. RlGI O B A R S t.SHE AR. CENT ER l

RtQlD-OF TIER BAR l

_ LONQtTUDINAL RESTRA1HT l

r 4

3.5 Effective-length Factors K for Buckling Evaluation In calculating for the buckling evaluation of the tied transverse hangers, one half of K values for the out-of plane direction presented in the Attachment E of Reference 2 can be used for the following members:

i) Post members of vertical trapezes.

ii) Post and tier members of cantilevered L-shaped hangers.

3.6 Alternative Analysis Method Generally, the simplified static equivalent analysis approach presented in Paragraphs 3.2, 3.3, and 3.4 shall be used for the reevaluation of cable tray hangers affected by the longitudinal tie of transverse hangers to the tray. However, when it is deemed appropriate, a longitudinal system model which consists of more than If a one longitudinal hangers in an analysis string may be used.

system model is used, the hinge connection between the traya and the hangers shall be assumed.

O I

i 9

I e

O i

5 i

I 1346m 8

. ~

_

Retrieved from "https://kanterella.com/w/index.php?title=ML20206T435&oldid=4043146"