ML20106F589
| ML20106F589 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 10/26/1984 |
| From: | Finneran J, Lotti R EBASCO SERVICES, INC., TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC) |
| To: | |
| Shared Package | |
| ML20106F574 | List: |
| References | |
| OL, NUDOCS 8410300309 | |
| Download: ML20106F589 (53) | |
Text
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'84 GCT 29 M1 M8 UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION
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t BPANC" BEFORE THE ATOMIC SAFETY AND LICENSING BOARD In the Matter of
)
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Docket Nos. 50-445 and TEXAS UTILITIES ELECTRIC
)
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)
( Application for (Comanche Peak Steam Electr.ic
)
Operating Licenses)
Station, Units 1 and 2)
)
)
AFFIDAVIT OF ROBERT C.
IOTTI AND JOHN C.
FINNERAN, JR. IN REPLY TO CASE'S ANSWER TO APPLICANTS' MOTION FOR
SUMMARY
DISPOSITION REGARDING THE EFFECTS OF GAPS We, Robert C.
Iotti and John C. Finneran, Jr., having been first duly sworn hereby depose and state, as follows:
(Iotti) I am Vice President of Advanced Technology for Ebasco Services, Inc.
A statement of my educational and pro-fossional qualifications was transmitted with Applicants' letter of May 16, 1984, to the Licensing Board in this proceeding.
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(Finneran) I am employed by Texas Utilities Generating Company as Project Pipe Support Engineer for Comanche Peak Steam Electric Station.
A statement of my educational and professional qualifications is in evidence as Applicants' Exhibit 142B.
We previously submitted an af fidavit regarding the effects of gaps on structural behavior under seismic loading conditions, which was filed with Applicants' motion for summary disposition of this issue, on May 18, 1984.
8410300309 841026 PDR ADOCK 05000445 Q
, Q.
What is the purpose of your affidavit?
A.
We address below the assert.fons made by CASE in its Answer to Applicants' statement of material facts accompanying our motion for summary disposition regarding the effects of gaps.- CASE's answer, filed August 13, 1984, is in the form of an affidavit of Mark Walsh (" Affidavit").
Q.
What is the first point you would like to make in response to CASE's assertions?
A.
CASE's principal contention is that Applicants may not assume in the design of anchor bolt connections that all bolts in a connection will react shear loads.I CASE premises its position on an interpretation of various AISC code provisions concerning vLlted connections which it believes demonstrate that App 41 cants' design practices regarding anchor bolts are ineJequate.
Accordingly, before addrecsing CASE's individual arguments we would like to make some general comments regarding the principles of design of bolted connections.
To understand the fundamental deficiencies in CASE's reply it is essential first to under-stand those principles and the intent of the AISC Code with respect to bolted connections, and in particular anchor bolt 1
An excellent discussion of the principles applicable to the design of bolted connections, and anchor bolt connections in l
particular, is also set forth in Cygna's response to Doyle Question 16 (April 19G4 Board Exhibit I at 35-39).
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i connections.
The anchor bolt connections at issue here involve either the connection of a base plate or a tube steel member to a concrete foundation with anchor bolts.
The AISC Code, which is titled " Specification for the Design, Fabrication and Erection of Structural Steel for Buildings," is primarily a code for the design and construc-i tion of buildings.
Most buildings consist of structural
' steel members either bolted or welded together with the structure anchored to a concrete foundation.
The Code dis-t l
tinguishes between steel to steel member connections and anchor connections.
The characteristics of these two types of connections in reacting loads are different.
CASE's assertions are premised in large measure on provisions of l
the AISC code which are intended to apply to steel to steel members, rather than anchor bolt, connections.
Those I
provisions simply are not applicable to the anchor bolt connection issues raised by CASE.
Specifically, CASE's assertions are founded on misconceptions of the intent of the AISC Code with respect to both the design of bearing and friction connections and the specification of tolerances for bolt holes.
With respect to the bearing / friction connection dis-tinction, CASE apparently does not recognize that the Code distinguishes between bearing and friction connections only l
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> with respect to steel to steel member connections, not anchor bolt connections.
This fact is apparent even upon-a brief' examination of the relevant portions of the Code.
First, with respect to steel to steel connections, Table 1-D of the AISC Code (Attachment A) sets forth allow-able shear stresses (the only type of stress for which the bearing / friction distinction is relevant) for fasteners, i.e.,-bolts, threaded parts, rivets, for both bearing and friction connections.
In contrast to Table 1-D, Table 1-C,
" Material for Anchor Bolts and Tie Rods" (Attachment B) does not draw a distinction between bearing and friction connec-tions.
Further, the text of the AISC Code separately addresses anchor bolts, e.g.,
Section 1.22, " Anchor bolts" (Attachment C).
As indicated in the Commentary on that section.(p. 5-149, Attachment D), the design of column bases and anchor bolts is not dependent on the classification of t
the connection as a bearing or friction connection.
- Rather, their design requirements are premised on the general nature of the connection being such that frictional resistance is sufficient to assure that shear stress against anchor bolts is not a critical concern.
In fact, the Code does not i
establish requirements for shear resistance of anchor bolts (see Table 1-C (Attachment B)).
However, the texts of Hof fman.and Rice, and Fisher (both texts cited by Applicants and CASE in their respective affidavits) do discuss methods for addressing shear in anchor bolts.
See Hof fman and Rice,
. pages 275,-279-80 (Attachment E) and Fisher (CASE Exhibi,t 1001 (Attachment F), p. 87).
Although Applicants and the NRC Staff have described time and again in this proceeding the nature of anchor bolt connections in a manner clearly consistent with both texts and the AISC Code provisions cited-by CASE,. CASE continues to misapply those principles.
The second point CASE _apparently fails to grasp is that because of the different considerations in the design of steel to steel as opposed to anchor bolt connections, the Code requirements for bolt hole tolerances are different for the two types of connections.
Section 1.23.4.1 clearly provides that bolt hole tolerance specifications for steel to steel connections are different from those for anchor bolts.
That section provides, as follows:
The maximum sizes of holes for rivets and bolts shall be as stipulated in Table 1.23.4 except that larger holes required for toler-ance on location of anchor bolts in concrete foundations may be used in column base details.
[Section 1.23.4.1 (Attachment G)2]
Other sections of the same portion of the Code provide further - evidence of the distinction to be drawn between steel to steel and anchor bolt connections with respect to hole tolerances.
For instance, Section 1.23.4.2 addresses member-to-member, i.e.,
steel-to-steel member, connections with regard to the use of standard holes.
In addition, oversized holes are permitted in " plies" (plate-to-plate 2
This page from the Code was Attachment C to our affidavit accompanying Applicants' motion.
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j r connections) of friction-type connections, but not bearing L
connections, by Section 1.23.4.3.
In contrast, holes'even
. larger than_the oversized holes described in Table 1.23.4 L
are permitted for anchor bolts. by Section 1.23.4.1.
- Thus,
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i CASE's' reliance on AISC Code provisions concerning restric-l tions on bolt hole tolerances for steel to steel connections to establish criteria for anchor bolt connections is misplaced.
l-In summary, CASE's assertions are premised on a mis-understanding of the principles of bolted connections and a
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misinterpretation of AISC Code provisions concerning differ-i ent types of connections and, in particular, the limitations applicable to bolt hole tolerances.
As discussed below, L
CASE's allegations are unfounded.
E Q.
What is your reply to CASE's comments regarding Applicants' i --
first statement of material fact (Affidavit at 1-5)?
I A.
CASE apparently does not disagree with this statement so
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long as the first bolt which reacts the shear load has not
" failed" when the last bolt begins to reac't the load.
CASE l
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i asserts, however, that au a consequence of the method of reaction of anchor connections a bolt "may have exceeded i
Cits] allowable shear capacity" and, thus, may have " failed" i
before the last bolt begins to react.
(Affidavit at 1.)
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is precisely this absence of failure which we addressed in I
t our original affidavit (at 4 through 9).
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, As we discussed in our original affidavit, it is well-recognized and accepted in the structural engineering field that not only will some bolts in a connection exceed the allowable that would apply to a single bolt, but some bolts may yield slightly. before the load is fully shared.
How-ever, this in no way means that the first or any other bolt will " fail", as CASE asserts.
In fact, we provided excerpts from texts of recognized structural engineering authorities discussing this condition as Attachments A and B to our original affidavit.
CASE acknowledges the accuracy of the portion of one text (Rice and Hoffman) cited by Applicants to illustrate the load sharing capabilities of multi-bolt connections.
(CASE did not review the other (Beedle).)
(Affidavit at 2.)
CASE attempts, nonetheless, to demon-strate that the first text is inapplicable to the present situation.
As discussed below, it is obvious CASE misunder-stands the manner in which anchor connections function under various loading conditions and, thus, misunderstands the intent of these authorities.
CASE's assertion regarding the Rice and Hoffman text is that it does not concern connections subject to " dynamic loads" which CASE apparently believes need be considered in anchor bolt connections (Affidavit at 2).
Speci fical l y, CASE argues that Rice and Hoffman do not address A307 bolts subject to " vibration" (Affidavit at 3) or " stress reversal" (Affidavit at 4), conditions which CASE believes apply to
-the anchor bolt connections at issue.
In the first instance, CASE incorrectly assumes that Applicants use A307 bolts as anchor bolts for safety-related pipe supports.
Applicants do not use A307 bolts as anchor bolts, but utilize A36 all-threaded rod.
This distinction is important because the rationale for the caution against the use of A307 bolts simply does not apply to A36 material.
In fact, contrary to what CASE implies, those limitations are not premised on a known limitation on the strength of A307 material.
Rather, the caution (see also ASME Code Table XVII-2461.1-1) arises because of an uncertainty in its strength.
Specifically, although A36 and A307 have similar material properties, the specification requirements for the two materials are different.
The A307 specification re-quires only a tensile strength test, i.e., minimmn ultimate tensile stress.
On the other hand, the specification for A36 requires both a minimum ultimate tensile strength test and a test for the minimum yield point of the material.
This difference in specification requirements is reflected in Table 1-C of the AISC code (Attachment B).
In the absence of minimum yield point data for A307, it is not appropriate to predict the strength of the material under loading conditions which may arise in certain connections.
Because such data 1.s available for A36 material, the same uncertainties involved with the use of A307 material do not
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_ _ _. _. _.. _ _ _ _ arise with respect to A36 material,3 Finally, it should be noted that the Section of the AISC Code (Section 1.15.12
( Attachment H))- referenced in the passage from Rice and
.Hoffman quoted by CASE in support of its assertion regarding A307 (Affidavit at 3) concerns steel to steel member connections, not anchor bolts.
In sum, CASE's arguments are premised on a provision Which is not even applicable to the type of, and bolt material used in, the connections at issue.
In any event, even if it is assumed that A36 material is subject to the samu limitations as A307 and that the Code
. provision referenced by CASE is applicable to anchor bolt connections, the " dynamic" loading conditions CASE asserts (Affidavit at 3-5) must be considered do not apply to the pipe support anchors at issue here.
The AISC Code provision referenced by Rice and Hoffman (Section 1.15.12 (Attachment H)) concerns " connections for supports of running machinery, or.of other live loads Which produce impact or reversal of stress."
Although that Code provision does not itself use the term " vibration," it is clear that the portion of the
' Code they reference is concerned with loads producing impact or stress reversal, such as result from running machinery.
The connections involved here do not support running 3
In fact, the Fisher text. CASE utilizes in support of its position provides that anchor connections (utilizing the
.large oversize holes recommended by Fisher) may be constructed using A36 bolts to create sufficient friction loads to ' resist shear forces.
(Attachment F at 89.)
. machinery.
It is not correct to equate, as CASE does, the small vibration due to the flow of water in the pipes with live loads such as from running machinery.
More importantly, CASE has incorrectly equated seismic loads with " stress reversal" loads causing fatigue ( Af fi-davit at 5).
The concern with loads creating stress reversal, such as from running machinery, is one of fatigue.
This fact, apparently not recognized by CASE although the Code Section cited by CASE (Section 1.15.12) refers to stress reversal caused by running machinery or other live loads, is discussed in one of CASE's own exhibits (CASE Exhibit 763F at p. 87), attached to this affidavit as Attachment I.
As noted by Messrs. Salmon and Johnson in CASE Exhibit 763F, one of the benefits of friction joints is their " fatigue resistance (i.e., no slip under varying stress or stress reversal consisting of many load cycles).
In contrast, seismic loads are not the type of loads which give rise to a concern for fatigue.
As stated in Sectior.
1.7 of the AISC Specification (Attachment J), "the occurrence of full design wind or earthquake loads is too infrequent to warrant consideration in fatigue design."
In sum, CASE's arguments regarding both dynamic loads and stress reversal are premised on a misunderstanding of the principles applicable to bolted connections and a mis-interpretation of AISC Code provisions.
As demonstrated
p b above, the provisions cited by CASE simply do not apply to the anchor bolts or the anchor bolt connections used at Comanche Peak.
Q.
What-is your response to CASE's assertions regarding Appli-cants' second statement of material fact?
A.-
CASE does not dispute the accuracy of this statement.
Rather, the only particularized contention made by CASE is that the bolt hole tolerances Applicants employ for 1" and
. greater anchor bolts are " oversized" as that term is generally used (Affidavit at 6-7).
The " oversized" hole question was addressed by CASE in their proposed findings on pipe support design issues (CASE Proposed Findings of Fact, August 22, 1983, at VII-10).
. CASE did not, however, specify the particular tolerances it believes constituted " oversized" holes.4 Nonetheless, CASE asserted that Applicants' tolerances constitute " oversized"
. holes and that industry practice was that with such holes only two bolts in a pattern could be assumed to react imposed shear loads (CASE Proposed Findings at VII-10).
Simply.to put this " oversize" assertion in context, we demonstrated in our original affidavit (at 6-7) that the term " oversized" when used with respect to hole sizes in bolted connections is generally accepted to mean hole sizes 4
In fact, the only previous indication by CASE of which we are aware regarding what it believes is an " oversized" hole was in Mr. Doyle's original testimony where he apparently considered an be " oversize" y(CASE Exhibit 669 at 122, tolerance greater than the bolt diameter
- 1. 24).
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. which have much greater tolerances than those Applicants em-ploy.
To illustrate our point we referred to provisions of the AISC Code which discuss " oversize" holes, albeit in steel to steel connections.
We went on to demonstrate (at 7-13) that CASE misunderstood well-recognized principles of bolt interaction in bolted connections and that the anchor connections employed at Comanche Peak were appropriately designed to react shear loads.
In its answer to our Affidavit CASE now utilizes various provisions of the AISC code (including the section we referenced simply to illustrate the generally accepted meaning of " oversized")
to contend that either Applicants' bolt hole tolerances should be certain sizes or our anchor bolt connections should be designed differently, i.e., as friction connections.
(Affidavit at 6-8).
As we demonstrate below, CASE has misinterpreted the AISC provisions it relies upon.
CASE's assertions are premised on AISC Code provisions applicable to steel-to-steel connections, not anchor bolt connections.
CASE's arguments are not, therefore, appli-cable to the type of connections at issue here.
CASE relies on Section 1.23.4.3 of the AISC Code (Attachment G).
As we previously discussed, that provision concerns steel-to-steel friction connections.
CASE does not acknowledge that, on the same page of the Code, Section 1.23.4.1 expressly pro-vides that holes for anchor bolts may be even larger thr.n the oversized holes permitted by section 1.23.4.3.
1 In any event, as we previously noted, even the AISC Code provisions concerning anchor bolt sizes do not address anchor connections loaded in shear.
In this regard it is informative to note that'because of this absence of specific guidance regarding bolt hole sizes for anchor bolts loaded in shear, Fisher (cited throughout CASE's answer) addressed the question in his text (Attachment F).
Fisher recognized that large tolerances for anchor bolt holes were desirable to facilitate construction but that use of these large holes for anchor bolts loaded in shear (a possibility in the absence of express guidance in the Code) could create a condition where " anchor bolts may not be able to deform sufficiently so that all four bolts could be counted upon to carry the load."~ Regardless, Mr. Fisher still recommends a hole size 1 1/3 times the diameter of the anchor bolt.
(Attachment F at 87.)
Fisher's recommended sizes are slightly smaller than the AISC recommended hole sizes for coli'mn baseplates (Attachment K).
However, Applicants' specified hole sizes are much smaller even than those recommended by Fisher.
In short, CASE's claim that not all bolts in Applicants' anchor bolt connection may be relied on to carry shear load is premised not only on a misinterpretation of the principles reflected in the AISC Code but the discussion in the text CASE itself cites.
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To illustrate clearly the various bolt hole sizes recommended by different authorities for various i
applications we have drawn up a table, as follows:
i AISC Max.
AISC Std. Size Appi f cants' Bolt AISC Oversfze, Steel Steel to Steel Practice ge_
Ffsher Base Plates to Steel Connection Connection for Anchor Bolts 3/4 "
.9975" 1.065"
.9375 "
.8125 "
.8125" 1"
1 33 1.3125 "-1.5 "
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1.0625" 1.125 "
1 -1/4 "
1.6625" 1.750" 1.560 "
1.3125" 1.375 "
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1 -1/2" 1.995" 2.00" 1.8125" 1.5625" 1.625" As,is evident from this table, Applicants' practice is to g
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' enploy bolt holes st6 aller, than any recommended sizes s
discussed by CASE other than those recommended for the AISC
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standard connection, which as previously demonstrated are applicable only to steel to steel connections, not anchor s
bolt conne$tions.
1 Q.
Do,y'ou have-any' other comments regarding CASE's arguments concerning oUr second statement of material fact?
.A.
Yes. sCASE also_c'ontends that Applicants do not inspect bolt
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holes'for size prior to installation, claiming that it has
" evidence" that'such inspections were not conducted (Affi-a davit at 8-9).
However, CASE's " evidence" that such inspec-tions are not performed.does not relate to the inspection of N
bolt holes in base plates; s
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, The first claim made by CASE is premised on an affi-davit by a Mr. Robinson concerning the size of bolt holes he apparently believed should be drilled for l'* bolts.
Robin-son does not contend, as CASE claims he does, that QC inspections of the holes were not conducted.
Robinson disagrees only with the size of hole which was permitted to be drilled for those bolts.
The size Robinson states the foreman directed be drilled (1-1/8" for a 1" bolt) is, in fact, precisely the size we have identified as Applicants' practice.
CASE has completely misinterpreted Robinson's affidavit.
CASE next claims that an allegation investigated by the ombudsman for Comanche Peak provides further evidence that bolt holes are not inspected.
CASE states that this allega-tion concerned an oversize hole which had been drilled "in a hanger base plate."
(Affidavit at 9-10.)
Actually, as is obvious from the very documents attached to CASE's affida-vit, this allegation concerns a hole drilled in the concrete floor for a bolt.
The allegation does not at all concern a hole in a base plate.5 Thus, CASE's discussion of this allegation misrepresents the facts of the matter.
5 The applicable portion of the investigation report reads, as follows:
During the interview [ deleted] made an allegation regarding an oversize hole (1-1/2") being drilled in the floor for a 1-1/4" Hilti bolt in a hanger base plate.
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i Q.
What is your response to CASE's allegations regarding Applicants' third statement of material fact?
A.
CASE's assertions regarding this statement of material fact are puzzling.
CASE apparently believes that the calculated factors of safety based on displacements are improper and not "in compliance" with IE Bulletin 79-02.
(Affidavit at J
11.)
In this regard, CASE mischaracterizes the intent of IE Bulletin 79-02.
As stated on page 3 of that Bulletin, NRC licensesas are to " verify that the concrete expansion bolts have the following minimum factor of safety 6 between the bolt design load and the bolt ultimate capacity determined from static load tests (e.g.,
anchor bolt manufacturers)"
(emphasis added).
This is exactly what Applicants have done in the design of anchor bolts.
What CASE does not acknowledge is that the Bulletin does not address the shear characteristics and capacities of multi-bolt joints, which is the subject of Applicants' motion and this affidavit.7 Further, it should be obvious to CASE that the question being addressed in our original affidavit (at 8-9) concerns the margin of safety in the ductility of the bolt which per-mits initially loaded bolts to deflect sufficiently, without failure, so that other bolts will be engaged to share the 6
The Bulletin recommends a factor of safety of 4, and Applicants use of a factor of 5.
7 It is also instructive at this point to refer to Cygna's discussion on design of anchor bolt connections (see n.
1, supra).
17 -
load.
Thus, the margin of safety for shear displacement is the most appropriate measure of the ability of the bolt to accept load without failure.
We note that we provided CASE with additional information to clarify whatever confusion may have existed with CASE regarding this aspect of Applicants' motion.8 CASE has not challenged that information.
In sum, CASE's reference to IE Bulletin 79-02 is misplaced.
CASE apparently does not understand the manner in which allowables for bolts are established and their relationship to the question of a multi-bolt connection's capacity to react shear loads, addressed in our affidavit.
As already noted, IE Bulletin 79-02 specifies that j
allowables are to be obtained by dividing the ultimate static test load by the desired factor of safety.
This allowable is then used in the design of connections, assuming all bolts will share the imparted shear loads.
The validity of that assumption,. which is founded on well-recognized and accepted principles of structural engineering, was demonstrated in our original affidavit where we evaluated the capacity of bolts to deflect, i.e.
displace, sufficiently to permit other bolts in the connec-tion to' share shear loads.
It is the margin of safety to this: capacity alone to which-we refer in our affidavit.
8 See Letter of June 28, 1984, to CASE from Applicants, item 2.
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Thus, CASE's comparison (Affidavit at 11-12) of shear displacement capacities with allowables calculated using ultimate static load test data is meaningless in light of the actual Bulletin requirements.
CASE's attempt to make such'a comparison is a further illustration of its misunder-standing of principles involved in the distribution of shear loads in anchor bolt connections.
Finally, CASE asserts that Applicants misstated in a letter to Cygna Applicants" practice regarding the design of Hilti anchor bolt connections.
CASE states that " Applicants informed Cygna that they [ anchor bolt connections] are
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-designed as friction type connections and will not move because they are pretorqued."
( Affidavit at 12. )
This representation by CASE is false.
Applicants never said these connections were designed as friction joints.
Rath er, we stated the joints would " perform" as a friction joint under certain conditions but were not designed as such.9 As 9
The full quotation from our letter to Cygna illustrates clearly CASE's misrepresentation of the substance of the letter.
It should be noted that Hilti' joints are designed using bolt shear allowables based on ultimate test loads divided by 5.
This is not the standard engineering approach to design a bearing or friction joint using code allowables for the bearing or friction con-dition.
Using our design approach, the Hilti joints since they are pretorqued, would per-form as a friction joint within their working loads.
At ultimate loads all joints (bearing or friction) would act as bearing joints.
[See CASE's Attachment F, at 9]
4
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- ----- already noted, Applicants have consistently taken this position throughout the proceeding.
CASE's claim to the contrary is simply erroneous.
CASE's further arguments
( Affidavit at 13-15) premised on this misconception are, therefore, meaningless in the context of Applicants' practice.
Q.
Do you have any comments regarding CASE's discussion of Applicants' fourth statement of material fact?
A.
No.
CASE does not present any new arguments in its dis-cussion of Applicants' fourth statement.
We have already addressed and.4emonstrated the errors of each assertion made by CASE.
Q.
What comments do you have regarding CASE's assertions con-cerning Applicants' fifth statement of material fact?
A.
CASE again asserts, without providing any new arguments, that Applicants' practice regarding bolt holes is incon-sistent with " code allowables."
We have nothing further to say beyond our previously stated position.
CASE also attempts once again to draw a distinction between the discussion in the Fisher paper regarding column base plate hole sizes and the anchor bolt connections Applicants employ.
CASE does not, however, directly dispute Applicants' fifth statement. (Affidavit at 16.)
With respect to CASE's interpretation of Fisher's paper, CASE contends that Fisher addresses bolt holes for column base plates that are not subject to " sufficient com-
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. pressive loads."
That point is irrelevant to the issue 4-here.
Fisher's only concern with the ability of anchor connections to resist shear through the anchor bolts, even if the connection does not experience sufficient vertical load to resist shear through friction between the concrete and the baseplate, is that "due to the oversize holes, the anchor bolts may not be able to deform sufficiently so that all four bolts could be counted on to carry the load."
(Attachment F at 87.)
As we demonstrated in our original affidavit, and as summarized in the fifth statement of material fact, this concern is warranted given the oversize holes Fisher recommends.
However, this concern is not warranted with respect to the anchor connections Applicants use which employ much smaller holes than recommended by Fisher.
Finally, CASE does not dispute the second portion of Applicants' statement, except to suggest that the safety factor should be calculated differently.
In this regard, we
~
have already addressed the purpose and rationale for considering safety factors based on shear displacement for addressing the' issues here.
CASE's assertions simply do not provide a valid basis for disputing Applicants' fi fth statement.
Q.
What comments do you have regarding CASE's assertions con-cerning Applicants' sixth statement of material fact?
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CASE does not dispute Applicants' statement.
CASE claims, however, that a different scenario than that addressed by Applicants must be considered regarding the deflection of anchor bolt connections.
(Affidavit at 16-20.)
As demon-strated below, the scenario CASE envisions is not realistic.
Before addressing CASE's hypothetical scenario, however, we discuss briefly another matter raised by CASE.
CASE asserts that Regulatory Guide 1.124 prohibits the assumptions underlying anchor connection reaction of shear loads (Affidavit at 17).
CASE's argument regarding the applicability of Regulatory Guide 1.124 to anchor connec-
-tions is misplaced.
CASE asserts that Regulatory Guide 1.124 limits the use of ASME Code provisions permitting increases in shear stress in ASME Code Section III supports because of the potential for non-ductile behavior ( Affidavit at 17).
CASE apparently believes -that the cited portion of the Regulatory Guide supports its assertion that a single anchor bolt in a connection may not be assumed to deform inelastically.
CASE does not attempt to square its claim with any of the authorities cited by Applicants and CASE which acknowledge and.indeed rely on small deformations to engage fully bolts in anchor bolt connections.
Further, although Regulatory Guide 1.124 clearly places a limitation on permissible increases in normal allowable
. stresses, it is not addressing anchor bolt connection reactions.
Indeed, the fact CASE still refuses to accept is
. _. _ _ _ _ that normal allowable stresses assume that all bolts in a shear connection share the load.
Implicit in that assumption is the possible inelastic action of individual bolts.
Therefore, Regulatory Guide 1.124 is not intended and should not be read to prohibit inelastic action in any single bolt of a connection.
Rather, it places limitations on the allowable shear stress of each bolt, recognizing that all bolts share the load equally.
Further, the provision of the Regulatory Guide quoted by CASE cautions against the
" potential" for non-ductile behavior.
As Applicants have fully demonstrated, the anchor bolt connections employed at Comanche Peak exhibit wholly acceptable and anticipated
" ductile behavior." Thus, the provisions of Regulatory Guide 1.124 cited by CASE are not relevant to the issues here.
Further, with respect to CASE's hypothetical scenario, CASE's claim that a more " realistic" condition exists than that which Applicants addressed regarding anchor connections is, itself, unrealistic.
The condition illustrated by CASE involves deformation of the base plate upon deflection rather than the anchor bolt.
CASE premises its argument on an interpretation of plate bearing stress allowables.
CASE apparently believes that in a tube steel / anchor bolt connection (it is actually A36 threaded rod, not an A307 bolt as CASE asserts) the tube steel will yield before the bolt.
( Af fidavit at 19-20. )
CASE's assertion is puzzling in that its explanation for this alleged " condition" is
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-- based on a comparison of allowable stresses (bolt and tube steel) in which the component with the higher allowable (tube steel) is predicted by CASE to yield first.
In any event, the error in CASE's analysis is apparent from the following.
At 17.67 kips (the allowable stress for the A36 threaded rod) the stress in shear across the nominal section of the bolt is 10 ksi (17.67 kips /1.767 in (nominal cross section of 1.5 inch bolt)).
This stress is, therefore, 100 percent of the allowable stress for the bolt.
The resultant bearing stress on the 1/2" tube steel, assuming all load is transferred through the bottom flange, would be 23.56 ksi (17.67 kips divided by (1.5" x
.5" (projected area of bolt)).
Using CASE's allowable bearing stress of 48.6 ksi, it is clear that even if the shear stress in the bolt is at 100% of its allowable, the bearing stress in the' plate is only at 48% (23.56/48.6) of its allowable.
Thus, strictly on the basis of percent allowable utilized it is apparent the bolt will yield first.
Finally, we have already addressed the inapplicability of AISC Code Section 1.15.12 to the anchor connections and loading conditions at issue here.
Thus, CASE's renewed assertion (Affidavit at 19-20) that this provision imposes limitations on Applicants' anchor bolt connections is
(
unfounded.
Q.
Do you have any comments on CASE's reply to Applicants' seventh statement of material fact?
- - " - - ~ ^ - - '
i A.
Other than referring again to our discussion above (at 8-11) regarding section 1.15.12 of the AISC Code and the type of bolts Applicants employ in these connections, we have no comments.
Q.
What is your reply to CASE's assertions regarding Appli-cants' eighth statement of material fact?
A.
CASE does not disagree with either portion of this statement of material fact.
Instead, CASE challenges a statement in our original affidavit regarding the damping effect of gaps.
(Affidavit at 21.)
Contrary to CASE's assertion, we have never stated that a higher damping value should be allowed.
We noted only that physically, greater damping is likely to result as a concequence of gaps than is ordinarily assumed in the analysis.
Because CASE otherwise agrees with this statement of material fact, we have no other comments.
Q.
Do you have any comment regarding CASE's position with respect to Applicants' ninth statement of material fact?
A.
CASE disagrees only with the second portion of Applicants' statement concerning the beneficial effect of gaps in seis-mic responses.
However, CASE does not assert that there is not a beneficial effect from gaps on the seismic response of the system as we stated.
Instead, CASE only claims there is less of an ability to predict the response of a system.
i
-n
~
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^
-.. -. ~
.. i We find it _ curious that CASE agrees only with the first portion of our statement.
The first portion clearly states that less energy goes into and is absorbed by the system when gaps are present.
That effect can only be beneficial, as indicated in the second portion of the statement with which CASE disagrees.
With respect to the alleged "inabili-I ty" of predicting the response of the system, that condition is related to the modelling technique and not, as CASE implies, to the physical energy input to the system which we are addressing in this statement.
Nevertheless, we note that it is theoretically possible, although prohibitively expensive, to model a piping system with all actual gaps and other nonlinearities, including inela tic behavior of sup-s ports, and, thus, to predict the detailed response of the system.
However,-the modelling techniques Applicants employ, as discussed in our original affidavit and addressed in the tenth through thirteenth statements of material fact, are premised on accepted, sound engineering principles which produce conservative result's.
CASE does not dispute this fact.
Q.
What comments do you have on CASE's reply to Applicants' tenth statement of material fact?
A.
CASE does not address the statement of material fac t.
The arguments made by CASE are irrelevant to the statement that each of the factors discussed in statements 7-9 cannot be 1
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~ I accounted for by the typical linear response spectrum analysis.
Accordingly, we have no comments on CASE's assertions.
Q.
Do you have any comments on CASE's reply to Applicants' eleventh statement of material fact?
A..
CASE does not disagree with Applicants' utatement.
- Instead, CASE asserts Applicants should be required to perform diffi-cult time history analyses for each of their supports or change the type of connections employed.
(Affidavit at 24.)
In our original affidavit we demonstrated the conserva-tism of linear response spectrum analyses such as Applicants j
use compared to non-linear analyses of the type CASE sug-gests should be performed.- We demonstrated that it is not 4
necessary-to perform non-linear time history analyses to obtain system responses which bound the expected response.
l-CASE has offered no argument to refute Applicants' statement or conclusion in thin regard.
Accordingly, CASE presents no 4
valid reason for Applicants to perform the non-linear time history analyses.
Similarly, CASE's assertion that Applicants could also change the type of connections employed is unfounded.
We
.have already addressed CASE's misunderstanding regarding anchor connections versus bearing / friction connections (see also discussion below regarding the twelfth statement of material f act).
- - - - - O.
What comment do you wish to make regarding CASE's arguments on Applicants' twelfth statement of material fact?
A.
CASE's response to this statement is illogical.
There is no relationship between our statement regarding identification of the effects of gaps by comparison of different analytical methodologies and CASE's claim that our statement means that
~
we should be required to install friction type connections.
We clearly demonstrated in our original affidavit that the linear response spectrum analysis (without gaps) predicts system responses (pipe stresses and support loads) which are generally higher than those predicted by non-linear time history analyses (with gaps).
Applicants' statement only relates to the fact that the lower responses predicted by the non-linear time histort analyses are due to a com-bination of the analytical method and the presence of gaps.
It does not mean that the results of the response spectrum analysis are not conservative (see also discussion regarding Applicants' thirteenth statement of material fact).
We have clearly demonstrated that Applicants have used response spectra analyses which are conservative and, thus, have conservatively accounted for the effects of gaps.
Q.
What is your position in regard to CASE's reply to Appli-cants' thirteenth statement of material fact?
A.
Although CASE disagrees with this statement, it apparently can find no other argument to refute the truth of the statement than by again referring to an alleged prohibition
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' in the-AISC code against the use of bearing connections in dynamically loaded structures (Affidavit at 25).
As we i
previously demonstrated, CASE's interpretation of the AISC Code _is erroneous.
Further, we demonstrated in our original affidavit the appropriateness and conservatism of employing the response spectrum method.
CASE does not even attempt to 2
assert that tha analyses discussed in our original affidavit
_are incorrect or that we have misinterpreted those analyses.
Neither has CASE offered any argument that contests the conservatism of _that method of analysis.
Thus, CASE presents no arguments which provide a basis for disputing this statement of material fact.
{
Q.
Do-you have any other comments to make?
A.
Yes, we wish to reiterate that nowhere have Applicants made use of damping factors not recognized by the NRC, as CASE would have the Board believe (see bottom of p.
25 of Affidavit), nor have Applicants failed to conservatively account'for the effect of gaps in the response of piping and support systems, as implied by CASE on top of p.
26 of CASE's affidavit.
Applicants agree that it would be difficult to analyze the systems in a manner that would k
//
realistically account for gap effects and possible non-linearities in the connections.- However, Applicants have shown that it is possible to analyze, and in fact have
' analyzed, the present as-built systems in a manner that conservatively accounts for such effects.
[
N Roberi'C.'Iotti 3 r+72-e n T &
- S Ssbacribed and sworn to before me this.2.6,b ew"rr ot"Lwsua-a J
day of October, 1984.
b:n % Y -.d w Notary P%blic U
D)y G-cmmo rsie a exptAes & Hack 2 t, I9 C C 4
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J C. Finneran, Jr.
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frR3F DF 73?*$
cre.v7v of Swows*< <--
Subscribed and sworn to before s this 26 day of October, 1984.
AuCxgar~
Notary Pu611c m y O m m e.c sro d ccx/trLfC m "2.f 1988, 9
6 4
l
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4-5 Attachment A BOLTS, THREADED PARTS AND R!-!ETS Shear Allowable load in kips TABLE l-D.
SHEAR Nommal Diameter d. in NI%l %Il l 1% I l' I 1% l lb H le Fv Load to 2
W h
'nt' Area iBud on Nonunai Diamen :n nation Type.
3068 4418 6013 7854 9940 t I ???
! 485 1 767 A307 STD 10.0 S
3.1 4.4 6.0 7.9 9.9 12.3 14 8 17 7 NSL D
6.1 88 12.0 15.7 19.9 24 5 29.7 35 3 F
STD 17.5 S
5.4 7.7 10.5 13.7 17.4 21.5 26.0 1 30.9 (C,ean D
10.7 15.5 21.0 27.5 34 8 42.9 52.0 l 61.8 med OVS.
15.0 5
46 66 90 11Ji,14.9 l 18.4 22.3 26.5 scale)
SSL D
92 13 3 18 0 23 6 298I368 44 5 53 0 LSL 12.5 S
3.8 5.5 7.5 9.8 12.4 15.3 18.6 22.1 A325 0
77 11.0 15.0 19.6 24 9 30.7 37.1 44.2 9.3 12.6 16 5 20.9 25.8 31.2 37.1 N
STD.
21.0 6.4 NSL D
12 9 18 6 l. 25 3 33 0 41.7. 51.5 62.4 74 2 x
STD 30.0 9.2 13.3 18.0 23.6 29 8 j 36.8 44.5 53 0 NSL D
18.4 26 5 36 1 47.1 5961736 89.1 106 0 F
STD. 22.0 S
6.7 9.7 13 2 17.3 j 21.9
- 2) 0 32.7 38.9 (Clean D
13 5 19 4 26.5 34.6 ! 43 7 54 C 65 3 77 7 mill OVS.
19.0 S
5.8 8.4 11.4 14.9 l 18.9 23.3 l ze 2 33.6 scate)
SSL D
11.7 16 8 22.8 2981.378 46 6 : 56 67.1 LSL 16.0 5
4.9 '
7.1 9.6 12.6 j 15 9 19 6 ~ 23 8 28.3 A490 0
98 14.1 19 2 7511318 39 3 47.5 56 5 34 4 41 6 49.5 N
STD.
28 0 S
86 12 4 16.8 22.0 j 27 8 NSL D
17.2 24 7 33 7 44 0 55 7 68 7 83.2 99 0 x
STD.
40.0 S 12.3 17 7 24 1 31.4 i 39 8 i 49.1 59 4 70.7 NSL D
24.5 35 3 48.1 62 8 l 79 5 I 98.2.119 0 141.0
~
4502-1 STD 17 5 S 5.4 7.7 10.5 13.7 17.4 21.5 '
26.0 30.9 jI D
10.7 15 5 21.0 27 5 34 8 42.9 52 0 61.8
- 9. 7 13.2 17.3 21.9 27 0 32.7 38.9 19 4 l 26.5 2
A502-2 STD 22.01 SI 6.7 34.6 3 43 7 54 0 65 3 77 7 A502-3
! O l 13.5 S
3.0 44 60 7.8 ' 98 12.1 14 7 17 5 STD l 9 9l A36 N
1 C 61
- 8. 7 11 9 15 6 19 7 24.3 29 4.
35.0 (f = 58 kso x
STD 12.81 S 39 5.7 7.7 10.1 12.7 15.7 19.0 22 6
!D 79 11.3 15 4 20.1 25 4 31 4 38 0 45 2 2
A572. Gr. 50 N
STD 11.1I S 3.4 4.9
- 6. 7
- 8. 7 11.0 13 6 16.5 19.6 i
g i f, = 65 ks0
!D 6.8 98 13.3 17 4 22.1 47 2 33 0 39 2 e
X STD
- 14. 3l S 4.4 6.3 8.6 11.2 14.2 17.5 21.2 25.3 2
! D 8.8 12 6 17 2 22.5 28.4 35.1 42.5 50 5 3
A588 N
STD 11.9~
S
- 3. 7 5.3 7.2
- 9. 3 11.8 14.6 17 7 21.0 f f, = 70 ks0 0
7.3 10.5 14.3 18 7 23.7 29 2 35 3 42.1 x
STD 15 4 Sl 47 6.8 9.3 Ill 115 3 18.9 22.9 27.2 OI 94 13 6 18.5 24 2 l 30.6 37 8 45 7 54 4
- F Friction-type connection N. Bearing-type connection with threads included in shear plane k Bearing-type connection wi+h threads excluded from shear plane
- STD Standard round holes (d + %~)
OVS. Oversize round holes LSL Long slotted holes SSL. Short slotted holes NSL. Long or short slotted hole normal to load direction (required in bearing-type connection)
'S Single shear D Double shear For threaded pa-ts of materials not hsted. use F< = 017F, when threads are included N
in a shear plane.
id F, = 0 22F, when threads are exctoded from a shear plane-When bearing-type connections used to sphce tension members have a fasterier pat-tern whose length. measured parallel to the line of force. exceeds 50 inches. tabulated values shall be reduced by 20 percent See Comrrentary Sect iS21 AMERICAN INSTITU TE Of STEEL CONSTRUCTION 4
.-.m.w
1 44
^ * * ^ * *
- 8 BOLTS AND THREADED PARTS ASTM specifications W
TABLE l-C.
MATERIAL FOR ANCHOR BOLTS AND TIE ROOS i
Stegth as' Waomum Waa o AsiM Proof v eul Iens.ie Diameter
'voe of x
1 Socc:hcatan load (un
%n' rn Mateat Unneadec a
(
j lC H
A307 60 4
A325' 85 92 120 rto1 ncl.
C QT H
74 81 105 l'ito I rincl.
l A354 Gr. 80 120 130 150
- 1. to 2'r ines A QT H u
~
105 115 140 over 2'r to 4 nci 2
A354 Gr. BC 105 109 125
- 1. to 2' r enc!
A QT H U si 95 94 115 over 2'r to 4 nct A449 8'
92 120
- 1. t a l inct C QT H. U 74 8,1 105 l's to Itr inci 55 58 90 134 'o 3 inci l
A490 120 150 Ir to 112 inct l A.QT H
j I
A687 l
105 l150'
- 11. to 3 inct.
l A QT NT l U
A36 36 l 58 8
C l u I
b A572 Gr 50 50 l 65 2
HSLA fU e
5 AS72 Gr. 42
-l 42 I 60 6
l HSLA J
U l'
I To4'nct i HSLA ACP 1 o 2
(588 50 70 I
46 67 over 4 to 5 nct 42 63 over 5 to 8 rnct.
- I
- aaracte 'stics.cmcaratie Avaaaoie in weathering t atmos;h, enc o"os,on res. stance )
2 to ASTM A242 and A588 steei Carbon C
=
QT
= Quencned and.empered Ahoy A
=
-:O*Fi Notch Tough (Charpy V-notch 15 ++ "t m
NT
=
HSLA = High Strength Low Alloy Atmosphenc Corrosion 'esistant ACR
=
Maximum (Ultimate Tensae Strength) l Notes ASTM specified mater at *cr anchor toits ! e rocs and siennar acci. cat ons can te ot-
'ained ' rom either specificaticrs +cr tare 3aec toits anc pucs ner -any used 3s con.
na stoc inat nav men te mreaded
^
nectors or for struc*urai materiai avaaac'e e ru i
The material supplier should be Consulted *or jvanat,hty 0+ see and,ength 2
a cat;co A563 Swtable nuts by grace ma, te otta ned ' rem ASTM Scec Anchor bolt material thar s auenc ed and temcerec s cula ^ot te weiced or meated to 'acihtate erection w
AM ERIC A N,NSTITUTE OF STEEL CCNSTAUCDON l
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structural Steel for Buildings 5 51 Attachment C SECTION 1.21 COLUMN BASES l.21.1 Loads Proper provision shall 'oe made to transfer the column loads and moments to the footings and foundations.
1.21.2 Alignment Column bases shall be set level e.nd to correct elevation with full bearing on the masonry.
1.21.3 Finishing Column bases and base plates shall be finished in accordance with the fol-lowing requirements:
1.
Rolled steel bearing plates 2 inches or less in thickness may be used without milling," provided a satisfactory contact bearing is obtained, rolled steel bearing plates over 2 inches but not over 4 inchm in thickness may be straightened by pressing or, if presses are not availauie, by milling for all bearing surfaces (except as noted in subparagraph 3 of this Sec-tion), to obtain a satisfactory contact bearing; rolled steel bearing plates over 4 inches in thickness shall be milled for all bearing surfaces (except as noted in subparagraph 3 of this Section).
2.
Column bases other than rolled steel bearing plates shall be milled for all bearing surfaces (except as noted in subparagraph 3 of this Sec-tion).
3.
The bottom surfaces of bearing plates and column bases which are grouted to insure full bearing contact on foundations need not be milled.
SECTION 1.22 ANCHOR BOLTE Anchor bolts shall be designed to provide resis*ance to all conditions of tension and shear at the bases of columns, including the net tensile components of any bending moments which may result from fixation or partial fixation of columns.
SECTION 1.23 FABRICATM N 1.20.1 Cambering, Curving, and Straightening The local application of heat or mechanical means may be used to introduce or correct camber, curvature, and straightness. The temperature of heated areas, as measured by approved methods, shall not exceed 1100*F for A514 steel nor 1200* F for other steels.
1.23.2 Thermal Cutting Thermal cutting shall preferably be done by machine. Thermally cut edges which will be subjected to substantial stress.or which are to have weld metal de-N posited on them, shall be reasonably free from notches or gouges; occasional notches or gouges not more than 3-inch deep will be permitted Notches or See Commentars Sect.1.5111.
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Structural. Steel inr Buddirigs e
Attachment D SECTION 1.22 ANCHOR BOLTS Shear at the base of a column resisted by hearing of the column base details against the anchor bolts is seldom. if ever, critical. Even considermg the lowest q
conceivable slip coefficient the verticalload on a column is generally more than sufficient to result m the transfer of any hkely amount of shear trom column base to foundation by trictional resistance. so that the anchor bolts usually experience only tensile stres3. Generally, the largest tensde force for which anchor bolts should be designed is that produced by bending moment at the column base. at times augmented by uplitt caused by the overturning tendenev ot a budding under lateral load.
Hence. '.he use of oversized holes required to accommodate the tolerance m setting anchor bolts cast in concrete. permitted in Sect.1.2141. is in no way detrimental to tha mtegrity of the supported structure.
SECTION 1.23 FAB RIC ATION 1.23.1 Cambering, Curving, and Straightening The use ot heat for st atehtenme or cambenne members is permitted for A514 steel, as it is for other steeis. Howes er. the maximum temperature permitted is lie F for A314 < teel, as contrasted with 12W F tor other steels.
1.23.1 Riveted and Bolted Construction-Holes A new section has been added :n this edit:on of the Specification. providing rules for the use of overs ted and, lotted hoies parallehng the provisions w hich have been m t he R' RBSJ -peatication ' -ince 197 2. extended to nt lude A. int bolts. w hich are outside the 3 cope of the high streagth bolt <pecificat.ons.
1.23.5 Riveted and High-Strength-Bolted Construction-Assembling Even w hen used m hearing-ts oe -he ir connections. A325 and A490 boits are required to be tightened te o T ot their tensile -trength. This mas he done either hv t he t urn-ot -nut meth, d.
hv a calibrated wrench. or hv use ot direct tension indicators Since fewer ta-tener, and stif fer connected parts are ms oked than is generally t he case with A ;o? bolts. the greater clampmg force is recommended in order to ensure solid wating of t he connected parts. H >w ever. because t he perf ormance of bolts in hearme is not dependent upon an as-ared mmimum level or high pretension. thorough n-pection requirements to usure tull and complete comphance wit h prettantenma enteria is not warranted This is especially t rue regarding the irhitrato n in-pet tion requirements of Sect edi ot the RCRBSJ j
-pet it ic ation.
Vi3ual es ident e < d -ohd seating of t he c<.nnet ted parts. and < >t g
wrench impacting to assure that the nut has been tightened,utficienth to present it trom loosening and talhna ott. is adequate.
N A
SECTION 1.21 SHOP PAINTING The surf ace condition ot, teel tramme dist!osed bv the demolttion of long-standing buildmus ha3 heen t >und to be unchanged f rom the time ut ;t3 eret tion, except at isolated spot, w here Nakage mas base occurred Where such leakaee l
i-not ehmmated. the present e or abwnce of a -hop coat is of minor nilue nce r
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Attachment E
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2 A. c. J N.fy 4 - F N
4-f Ag, N m t
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A, q l g.
ha
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pA6 _f AA a
y N
Ass
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x Ag h 4A,d Pi e r-Footing l
FIG. 5 6 Column Base Plates on Concrete.
f (4) When the supporting surface is wider on all. siies than the loaded area, the allow.
able stress may be multiplied by s/A /Ai < 2...... (10.14.2)*
2 (5)Ai = the loaded area; A2 = the area of the lower base of the largest frustrum of a right pyramid within the footing with A as its top and with side s'. opes of I r
v,ertical to 2 horizontal...... (10.143)*
{
See Fig. 5 6 for the relationships between loaded area and unloaded areas. One furthe I
comparison of the codes for concrete and the AISC Specifications is needed to apply r!ne bearing stresses of the concrete code for steel base plates. The allowable stresses of the concrete code are called the " design" stresses under " design" loads, U.
U = 1.4 D + 1.7 L...... (Eq. 9 1)*
It will be noted that the ACI allowable factored load stresses can conservatively be di-vided by 1.7 for the allowable stress under total dead plus live loads as used in the design
'of steel columns by the elastic method (Part 1); or that the factored load for design of steel columns by the plastic method can conservatively be used directly with the ACI design stresses. Applying the reduction suggested for elastic load, the allowable stresses become:
F,, = (0.S5) (0.70)fl/1.7 = 0.35 fl.
... Eq. 5 1 U
F,, = (2) (0.35)fl = 0.70 fl...
. Eq. 5
. f, The authors suggest the use of Eq. 51 for the design of base plates supported on rein-
- E forced concrete pices, and Eq. 5 2 for the design of steel base plates supported on con-h i
crete footinrr to avoid interpolation for variable ratios s'A /A :. It will be noted. how-l 2
ever, that the ACI Code requirement (10.14.2)* does provide the basis fur tr:re:d.auen.
(See Tables 5 2 for base plate designs prepared upon the basis of Eqs. 51 and 5 2 with h y i
fl = 3000 psi for columns of Grade 50 and base plates in Grade 36.
3 har Bolts for Column Base flares. The Specificatior.s require that " Anchor bolts shall be designed to provide res: stance to all conditions of tension and shear at the base p
l of columns..
"(l.::
There are no explansuons of this section in the Commen.
1
{ '.
t
- " Building Code Requarernents for Reinforced Concrete."(ACI JIEJ11 and 1975 reviuons Nur -
i*
bers in puentheses are se:tiens or Equations from " building Code Requirernents for Reuiforced 3
Concrete."
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.m i.m
..m cc S ::;;; ::;'; ::=
,u. u l m.m.. l..... n.
.......... m.,
.....,.. m.
.i. m...........,,.
n
..n n.,.
.m
.m
......m t
W,.......,,
L nIin.
.,....... m.,...... n.
..u...
.m.
. m.
l-N
-I
. i m.
.. 4.
w.
,o n
..um m...
p.....
tary. The AISC Specifications provide no allowable concrete stresses for the develop.
d"* l !-ll*
ment of such anchor bolts in tension or in bearing upon concrete. The 1971 ACI Build.
h:2 PC ** ~.
ing Code (318 71) and the 1975 revision also fail to provide allowable stresses for bolts (plain bars) in bearing or for their development in tension. Older ACI codes, however,
- b..
C.g. ;.-
traditionally allowed for plain bars 50 percent of the bond stress allowed for deformed p
bars but not to exceed 160 psi in tension or comoression for any strenc:h of concrete
[,.-l:? ? " * *""
(ACI 318 63. Section 1301 (c)(4)). The authors suggest that this value be used for al!
- %
- .l~ Q plain anchor bolts using the full length of the bolt whether hooked or straight. For important footings or where uplift tension may involve large forces, it will usually be t
I 1
O i
- l.__.,_._._._
__ l l
"g7 e
l @3 280 STRUCTURAL DESIGN GUIDE TO ATSC SPECIFICATIONS FOR BUILDINGS g
preferable to use an embedded base p! ate at the lower end of the bolts as a positive anchorage. This positive anchora;;e should be provided where boli diameter > 1.5 in.
Q; W
Since both steel and concrete code requirements for bolts in bearine are lacking. pro-3(f]
vision of anchor bolts for shear resistance becomes a matter ofjudtment. For very large l
,. K shears as at the base of tall buildings, a positive provision for the transfer of shear to the p'N foundations at the first floor level will avoid the uncertainty. He column continuing to 3
the footings below the basement level can then be designed readily for concentric com-pression. Another device to provide positive shear transfer is the use oflugs welded to the base plate for embedment in the concrete. For lesser shears or where most of the j
shear can be considered to be resisted by friction and where no other means are avail-f}, i able, the authors suggest using shear dowel forces upon the anchor bolts as assumed in i.
the design of pavements for transfer ofloads across a formed joint.
r.
.P.
l
. NerSh,ca'r Total Shear:p = 0.2 on Base Dia.
- ~
Bolt to Bofi(Ibs.)
Bolts Tightened,50 ksi
' _E.
}.
1,200 lbs.
j j
j' 2,500 3,200 lbs.
l 1"
3,000 5,000 lbs.
k 1}"
4,000 12,000 lbs.
2*
4,500 20,000 lbs.
2}~
4,700 30,000 lbs.
II 3*
4,900 45,000 lbs.
[ llh
" Load Carryins Capacity or Dowels at Transverse Pavement Joints," H. Marces:
q ACI Proc. V. 48, No.13. Disc. P. C. Disario: Closure, Marcus rs " Anchor E
Bolts."
l l r ll U D
,,K SpecifiCatsons t...
- j y ?
General. Efficiency in design time, fabrication, and erection for routine conditions,sug.
l" gests that the selection of connections be considered part of the detailer's function. He l
E Y
l,'
designer must, of course, provide the design requirements necessary for another to com-i plete the details of the connections. For special conditions, any special design require-rl N
ments or limitations on the types of connector materials, connection fasteners,etc.must i
A also be provided either as specification requirements or details and general notes on the j k ?
design drawings (1.1.1).
- jqH, Flexible Connections (Type 2 Construction). A general note to indicate the type of con.
y*
struction on design drawings should be standard practice, although Type 2 construction L
is often taken for granted unless otherwise specified. To permit maximum economy
{
in detailing connections. it is also preferable to show all beam reactions on the design 8
drawings. Otherwise it is customary to detail these connections for half the uniform load
,l capacity for the section, span, and grade of steel used. Showing all reactions not only permits some economy in those less than half the uniform load capacity,but also aids the 2 2 designer's memory not to omit showing those which exceed this amount and therefore j
l must be shown.
r l
l On his own initiative, the detailer should not be expected to select connections to create nil end moments or to provide the required rotation capacity. The designer should
?
indicate the typical resterials, type, and details of the connections desired as well as any special details such as coped bottom flanges for more rotation capacity where they are
[!
critical to the design. For eccentric connections such as brackets, the design drawmss l
1 i
Attachment F CASE EXHIBIT 1,001 Structural Jetais in 'ncustrial Buicings JAMES M. FISHER 1
The recent AISC lecture series on " Light and Heavy In-ht?J.NM,*i
[%'.*?- [1*f.'.'s dustrial Buildings"I generated considerable discussion concerning details and design assumptions relative to (1)
.Q-I I
steel joist and joist girder systems and (2) column anchor bolts. These two topics, although unrelated, were of major (pj concern to many engineers and fabricators in attendance.
This concern centered around the apparent lack of appli-cation of structural engineering principles to designs and 1
I details. The purpose of this paper is to point out design and g<
detailing problem areas associated with these topics, to help designers avoid structural problems in future designs.
% m.msesem.
STEELJOIST ANDJOIST GIRDER SYSTEMS t--
Bottom Chord Extensions-Open-web steel joists are Mr.1. Typical detad ofjoist andjoisa girder at column designed by the manufacturer as laterally supported simple beams under uniform loading. Using a joist in any other If a 40.in. deepp..ist girder was used, the resulting force way or loading requires special consideration by both the design engineer andjoist supplier. One common example in the top and bottom chords of thepast gtrder would be of this is to provide a bottom chord extension in order to aPproximately 50 kips. The detail commonly used for this achieve rigid frame action for lateral stability. Although type of construction is shown m Fig.1. If not designed and it is usually more economical to use the roof diaphragm detailed properly, this connection may result (if the system system or X-bracing to carry the lateral loads to rigid walls, is loaded) in the following:
this cannot always be done. The designer then may resort
- 1. Buckling of the bottom chord of thejoist girder.
to bottom chord joist extensions.
- 2. Shear failure of the bolts connecting the joist-girder As an illustration of the magnitude of the forces which to the column, which in turn can result in a secondar"'
are developed through the use of bottom chord extensions, failure of the pist seat resting on top of the joist examine the fo!!owing situation. Assume that aptst girder girder
- has been designed to support a total roofload of 45 psf.This loading consists of a 15-psf dead load and a 30-psflive load.
. It should be noted that 13.5 in.of % in weld would be If a 40-ft x 40-ft bay system was used and assuming the required to transfer the top chord reaction into the column bottom chords welded to the columns after the applica.
cap. In addition,13.5 in. of weld would be required to tion of all dead load, the resulting live load end moment in the transfer the bottom chord force into the stabilizer bar, plus joist girder would be M = %2 wl2 = %2 (30 X 40)(40)2 an additional 13.5 in to adequately attach the stabilizer bar
= 16,000 lb-fi = 160 kip-ft.
to the column.
A related problem relative to bottom chord extensions occurs with tilt-up or precast wall systems. Wall cracks will occur due to the continuity created by the detail shown in James M. Fisher is nce President, Computerszed Structural Fig. 2. The designer is encouraged not to extend the bottom Design, Inc., Milwaukee, insconsin.
chords in these situations. If it is necessary to do so, then the This paper ues presented at the A/SC National Engmeenng resulting moments and forces must be supplied to both the Conference in Dallas, Texas.on May 1,1931.
Joist manufacturer and the wall designer.
THR0 OVARTER / 1981 j
1 g.
i h ia.
facturer of the actual loading conditions. The designer must 4
also check both the roof deck capacity and thejoists for the drifted snow condition. Ieads in excess of 120 psf have been
- ynow O ""
I known to occur.
V. h lj seam roof was a major breakthrough in the design of metal
- 8 Standing Seam Roofs-The development of the standing h.
bygg.md...y roof systems. The system was first introduced in the late I
x~4. cas l
'60s and today most metal building manufacturers either offer it or plan to provide it in the near future.The differ-
^!,
I ence between the standing s:am roof and lap seam rooflies
/
in the manner in which two panels arejoined to each other.
- g-x eg,.gs; e
The seam between two par.els is made m the field with a
== = si= % w au.
..c W sums. =.
tool that makes a cold formed weathertight joint. (Note:
some par.els ean be seamed without special tools.) Thejoint N "'
DN.I.E'iO uno ess is made mhe top of the panel.The standing scam roof is also umaue in the manner in which it is attached to the Fig. 2. Detailar precast or tilt.up well seconda:i structurals. The attachtaent is made with a clip concealed inside the scam. This clip secures the panel to the purlin orjoist, but allows the panel to move under thermal The designer should not create continuity by arbitrarily expansion or contraction.
using bottom chord extensions. If this is done, the connec-The special characteristics of the standing seam roof tions must be designed for the imposed loads, and the re-produce a roof that is superior to other exposed metal roof sulting forces given to the joist manufacturer and other systems. A continuous single skin membrane results after design professionals for proper joist and connection de-the seam is made, since through the-roof fasteners have sign.
been eliminated. The elevated seam and single skin member Provides a watertight system. Due to the ss.periority of the Stepped Elevations-The situation shown in Fig. 3 occurs standing seam roof, most manufacturers are willmg to offer commonly in areas where stepped roof elevation conditions c nsiderably longer guarantees than those offered on lap exist. It is insufficient to select ajoist based on an equivalent seam roofs.
uniform load (uniform load producing the same maximum Sever 31 Potential design errors can occur when using bending moment as the actual loading) and a maximum end standing seam roof panels with joists. It should be recog-shear condition. This procedure will not guarantee that the mzed by the designer that standing seam roofs have very top chord of thejoist is adequate for the higher !ccalized little inherent diaphragm strength or stiffness and, there-uniform load, or that the diagonals in thejoist are adequate.
f re, cannot be relied upon to resist lateral,n-plane forces i
Since the designer does not have access to thejoist member r to Provide lateral stabihty to the jo,st top chord. Joists i
sizes at the time of design, he must inform the joist manu.
are typically designed assum, g fulllateral support to the m
top chord but,if a standing seam roofis used, thejoist must be designed considering this lack of lateral support. If the g gN inadequate lateral support to the joist is called to the at-tention of thejoist manufacturer, he can provide the re-hv N
% N quired support by designing thejoist top chord based on the s
N discrete bracing points provided by bridging spaced closer
-- - ~~1 than for standard designs.
3 Because of the very light dead load associated with the IbMM/Q standing scam roof,it should also be noted that deflection criteria (L/240) usually controls thejoist size. In addition, because of the li ht dead load, roof uplift criteria must be 5
carefully considered.
Crane Loads-Joists have been used to support un-derhung rane systems. However, thejoist supplier cannot simply be given the loading due to the crane with reactions assumed to be at panel points. In practice, the underhung crane beam reaction will not be resisted at panel points, but i
will in all likelihood be resisted in a manner similar to that Fig. J. Snow dnft condition for ronflwr loads shown in Fig. 4. The bottom chord of the joist must be 84 EC'JEERM 10VRNAL i A8,'ERCA e,$ TIT l'TE QC STEEL CONS'NCTION
l i
ii t i
- 1 ur t m (R q
P H.
l
/
tutins (
N I
/
se g.
I
.d l.
Fig..t. Hanging crane load d
checked for combined bending and axial stress. In addition, the welds in thejoist must be designed based on fatigue considerations. A superior method would be to design a Figd. &icrete dear me d,Q,Qr er a suith head harness over the p, ast so the load is applied to the top chord.
- Inadequate development of the anchor bolts for ten.
FloorJoists-One of the most frequent problems associ-sion '
tied with floorjoist construction is floor vibrations due to
. Inadequate development of concrete reinforcing human impact. This problem is likely to occur on open floor steel systems when a 28/2-in. thick slab of lightweight concrete
. Improper selection of anchor bolt material is used on spans from 26 to 30 ft. Damping resulting from
. Inadequate base plate thickness partitions, file cabinets, heavy it.rniture, etc., will signifi-
. Poor placement of anchor bolts cantly reduce the problem. If open floor areas must be used,
. Shear in anchor bolts increasing the mass by increasing the slab thickness is in
. Fatigue general the most economical solution. A full treatment of vibrations of steeljoist concrete slab floors has been pub.
Guidelines and suggestions for each of the above prob! cms lished by the Steel Joist Institute.2 are provided below. In addition to the comments below, valuable design inbrmation relative to anchor bolts is I
~
BOTTOM CHORD BRIDGING mation will be published in Appendix B of the ACI Sta -
Bottom chord bridging is extremely important to the dard Code Requirementsfor Nuclear Safety Related Con.
structural performance of a steeljoist floor or roof system.
crete Structurer (ACI J.19) in the near future.
Bottom chord bridging serves to:
Development of Anchor Bolts for Tension-Anchor
- 1. Help align thejoist during erection.
bolts that are not quenched and tempered and are I in. or
- 2. Brace the bottom chord for wind uplift require-less in diameter may be hooked to increase their pull out ments.
resistance. Quenched and tempered anchor bolts greater than I in, can be threaded and embedded in the concrete 3.. l aterally brace the p..ast diagonals (.m combm.ation with a nut and washer.
with the bot orn chord).
PCI research has shown that hooked anchor bolts fail Item 3 is often an unrecognized function. Since the di.
by straightening and pulling out of the concrete. This agonals of a joist, joist girder, or truss are in effect individual failure is precipitated by a localized bearing failure on tae colurr.ns, they must be laterally st pported to prevent their hook. Headed anchors or threaded rods with nuts and buckling out of plane. Bottom chord bridging in combi.
washers fail by a concrete cone mode. See Fig. 5.
nation with the horizontal tiexural capacity of the bottom The pullout capacity of a hooked anchor bolt or a bar chord must provide the required lateral strength and embedded in the concrete with a nut and washer can be stiffness.
calculated as follows:
- 1. Obtain the anchor bolt tensile capacity from AISC COLUMN ANCHOR BOLTS allowable stresses. See Table 1.5.2.1 of the AISC Improper design and detailing of anchor bolts and column h!anual.3 base plates have caused numerous structural problems in
- 2. Obtain the concrete pullout value from Sect. 5.17 of industrial buildings. Problems relative to design and de-the PCI design handbook
- for headed anchors. or tailing include:
check bond and bearing for hooked anchor holts.
SS THE CUAMF't > 9t1
1_ _ L. _
_r r r. ~ ~ ~
1 1~~--
~
^^
t 4
Ermple-Determine the allowable pullout value of a For the bar with washer and nut:
%-in. dia. A307 anchor bolt embedded 12 in. in 3000 psi A. = Vf (12) r (12 + 3) = 799.72 in.2 concrete. Assume (a) that the anchor bolt has a 4-in. hook; Ultimate concrete capacity then (b) that in lieu of the hook a threaded md with a nut
= 0.85 (799.72)(4 X 1.0 X V3000) = 148.9 kips cnd washer is used.
Working capacity = 148.9/1.7* = 87.6 kips Solution (a)-Hook:
Use bolt tensile capacity of 8.8 kips.
4 From the AISC Specification, Table 1.5.2.1:
It should be noted that the calculation shown above was F, = 20 ksi based on an isolated anchor bolt for which the failure cone Tensile capacity T = F,A = 20 X 0.44 = 8.8 kips shown in Fig. 5 does not overlap with adjacent failure cones.
From the PCI Design Handbook:
"The PCI handbook also contains equations and criteria for CI"'' "I * "* 'I*"
Bond strength = rdL (250) where d
= bar diameter Development of Reinforcing Bars-In addition to L = embedment length making sure that the anchor bolt is sufficiently anchored 250 = ultimate bond strength in psi (non. oily in the concrete, the steel reinforcing in the foundation steel) system must be positioned and detailed to proside a suitable Bond strength = x(3/4)(12) (250) = 7,070 lbs development length. See Fig. 6. The reinforcing must be developed in accordance with ACI (318-77) requirements.
Since anchor bolts are often oily due to thread cutting.
These requirements may dictate that the bars be hooked the desi ner may wish to neglect the plain bond capacity.
or that the anchor bolts be provided in lengths longer than 5
Further, pretensioned high strength anchor bolts should calculated above, so that the rebars can indeed be developed.
not be designed on the assumption of transfer of pretension Tabulated in the PCI design handbook on pages 8-19 and by bond. Progressive loss _of bond will result in transfer of 8-20 are development lengths for #3 to # 11 bars in 3000, the tensile force to the head and a consequent reduction of 4000, and 5000 psi concrete. If the reinforcing bar is not pretension.
positioned against the anchor bolt, then the development Assuming uniform bearing on the hook, hook strength length Is should be measured from the intersection of the
= cf/dL' rebar and the assumed conical failure surface.
where c = 0.7 Selection of Anchor Bolt Material-Consult local fab.
// = concrete strength ricators for availability of materials. As a guide, use Table d = bar or hook diameter I.C," Material for Anchor Bolts and Tie Rods." pg. 4-4 L' = hook length of the Eighth Edition AISC Manual.
Hook strength = (0.7) (3000) (3/4) (4)
Base Plate Thickar The design procedures illustrated
= 6,300 lbs in the section " Column Base Plates"in the Eighth Edition Total pullout capacity based on embedment = 13.37 !dps (ultimate) e A multsplier of 1.3 tsmes the loadfactor shown would be con.
Assuming a load factor of 1.7, a!!owable pullout capacity sistent with PCI recommendarsonsfor " sensitive"connec.
r
= 7.86 kips tsons.
Use allowable load = 7.86 kips
~-
-*A*.2*
Solution (b)-Nut and Washer Combination:
Check pullout in plain concrete.
From Sect. 5.13.2, PCI Hr.ndbook:
f '" '" * ' ** '
Ultimate concrete capacity = 4A, (4 A /g)
,4( f **** * *
,=,
..~..a T..
- I si where d = 0.85 A. = area of an assumed failure surface 6=~**-
+
t.
J d,'d/ -- g,7 = = w For the case shown in Fig. 5:
5 A. = dit w(1, + d,)
~~
I, = embedment length (Fig. 5)
- d. = diameter of washer or head (Fig. 5) l-A = 1.0 for normal weight concrete (PCI Section 5.6)
Fit. 6. Pier driosi m;
ENOBE99G JCLN84L / AMEfMCAN INSTITUTE OF SitEL CONSTMf'ON
- a.
~
g
.y
)y v
m u
.v 3,
1 7{p g
+
y a
, ';,a L
i i' AISC Nfan'ual may be followed. For small base plates. the rew method illustrated in the Manual can be used to obtain required plate thickness; however, thinner base plates can
.., (!,
. be obtained using yield line theories. Metal building manufacairers have used yield line thec. ries to establish base
- @~
tQ
?
plate thicunesses with success for many years.
l-Placement of Anchor Bolts--There seems to be no guaranteed solution to the anchor bolt location problem.
Since it can be assumed that anchor bolts'will not be placed exactly as indicated on the drawings, overside holes in the base plate are a must. The larger the anchor bolt, the larger the oversize must be. The author's office has established s
s a rule-of-thumb that the size of the hole in the base plate i
should be approximately 1 % times the anchor bolt diam-
,g,7 g
eter.
-r 1y Shear in Anchor Bolts-The AISU Commentary states
- 2. FloorSlabs 4
" Shear at the base of a column resisted by bearing of the In many cases the condition shown in Fig. 8 exists. In column base details against the anchor bolts is seldom, if these cases calculations will show that many timer. the even critical. Even considering the lowest conceivable slip
~ shear can casily be transferred from the column simply coefficient, the vertical load en a column is generally more by the bearing of the column against the floor slab. In than sufficient to result in the transfer of any likely amount some cases the shear must be transferred using hairpin of shear from column base to foundatica by frictional re-bars or tie rods. Many problems have occurred when sistance, so that the anchor bolts usuallfexperience only the hairpin bars are placed too low on the anchor bolts, tensile stress.
N as shown in Fig. 9a. The problem can be avoided as The above statement is true for most multistory build-shown in Fig. 9b.
. ings; however, in industrial buildings uplift forces in con-
- 3. Thrust Bars junction with sh-ar loads may exist simultaneously, and the designer must take proper measures to transfer these Thrust bars such as the one shown in Fig.10 are used shear forces. Several mechanisms exist for shear transfer; in industrtal buildings when shear forces become sig-these will be discussed below:
s t
- 1. Anchor Bolts:
The author does not recommend that more than two anchor bolts in a cluster be used to transfer the base.
shear unless all anchor bolts are "!caded in." The ra-4
,C1,*2.,[,.m, I
3 tionale behind this statement is that in all likelihood only }
l two anchor bolts will ever be in braring in a base p! ate. :
I i-connection. Shown in Fig. 7 is a base plate consisting -
M * *"
cf four 1-in. anchor bolts. Under normal conditions, only one of the anchor bolts will be in bearing as initially :
pg g y installed. Under the application of a shear load, the
+
column will slip and rotate so that perhaps another '.
anchor bolt could go into bearing. Due to the oversize,
M holes, the anchor bolts may not be able to deform suf-ficiently so that all four bolts could be counted upen to 3
~ **
9 f'*'"""", "
- or bo strength in combined shear and tension
. %ill be controlled either by the bolt material in combined y,
3 d shear and tension or by th' concrete under combined e
w g
S hear and tension. To check combined stresses in the bolt
^,
s
[ 'I.
material, it is suggested that the _AISC interaction l
equations be used. The PCI handbook contains proce-dures for determining the concrete stre'ngth. The steel t*,,y,N-~
"E NNWN m,,,
mn l
designer should be extremely careful when working c.
.,A/
b a* s**aac
. s with concrete strength equations; since they are always written in ultimate strength terms.
Rg. 8.'. Transfer of shear through Jtoor slab 2:
i x
\\-
I
\\
87 1
- i
\\
MLD CUAniER i 1991
nificant. This method of shear transfer is positive and direct. The thrust har should be fillet welded to the bottom of the base plate to develop its full bending strength. A design example is shown below:
m a '" * * * * **
l
/ e.
Given:
v ' '
p'Lic'i x ~
"a*Zi" * "'
Base plate detail in Fig.11, where:
G = 1 in.
e.~ c = =.
1-L,,,,,,,,,
V = 50 kips P*'
i=****ia**
. r.
- g=.,.
f,' = 3500 psi b = 12 in. (length of thrust bar) 3, Solution:
Check bearing on plain concrete:
s,..i. c.sv ~
From PCI handbook, p. 3 7:
V, = (1.7V) = cC,(70AVJ/)(s/d)3bd p==.ie.i.es..
where
_ 'INI N
(1.7V) = factored shear = 1.7 X 50.000 lbs c = 0.70
. :t '
..'l.
C, = 1.0 (zero tension) lll ' '.' ll '
A = 1.0 (normal weight concrete)
. 2.,,.,* ').-
s= d/2
.f.,
V,, = 1.7 X 50,000
= 0.70 (1.0) (70) (v'3,500) (1/2)1') (12)d cb) d = 3.08 in. (say 3 in.)
Fig. 9. Placement ofhasrpin bars Compute thickness, assuming cantilever model:
M, (bar) = (1.7V)(G + d/2)
/_ }
= (1.7 x 50)(1 + 3/2) = 212.5 kip-in.
l c o ~ c.a. s 2
E, = 36 = (212.5 x 4)/12:
oe's i*'
g j
l e
=
+
_ e. mom t = 1.40 in.
+ $/ I b+
Use 1%-in. thick plate.
/ I I s,e s saw p_.Aw v
,i
- 1 q
~ _...
- p. j.]
t
,,..u..
=
""h
.g
= =ss s, j-;t;*:X*""'
<.. ~,.
,L n ov = =x
.a.....,.
s g
m cwon -
i.
Cul'El",.
d' erm %*
. =s.. )
- s-J. _. \\ -W* *h..' *
- l..,..
Fig.10. Detast of thrust bar Fig.11. Design example 88 ErC'.YER:NG JOURM i AA'EP.lCAN INSTITUTE Oc STEE'. CONSTRUCTION
]
m
Jz, Compute fillet weld leg size, D:
the designer should specify a procedure for tensioning and
'12.5
'"' P'C" ""
1 1
D=
The designer should take into account prying action for l
,,1.5(1.7)(21.0)(0.707)(12)4 tensile fatigue situations. A factor which must be considered l
50 is the possibility of overload. A tensiie overload can cause 21.0(0.707)(2)(12),'
yiciding of the bolt and thus a partial or complete loss of the 1
initial clamping force. Base plates for anchor bolts subject
= 0.608 in.
to cyclic fatigue loading in tension should be conservatively Use %-in. fillet weld.
designed to minimize or preclude prying action. See Guide to Design Criteriafor Boltedand Rivetedjoints,6pp.266,
( Frictia 267 and 279, and AISC Specification Section B3.
A method of providing shear resistance in the absence of gravity dead orlive loads is to pretighten the anchor REFERENCE 5 bolts and transfer the load by friction. Based on an initial
- 1. Fisher. fames Af.andDonaldR. Buettner Light and Hesq preload load in the anchor bolts and a coefficient of Industrial Buildings Amencan Inststs sc o/ Ster / Corutruction, friction of 0.4 to 0.6 between concrete and steel, an al-Chscago, Ill.,1979.
Iowable shear load can be calculated.
- 2. Vibration of Steel Joist Concrete Stab Floors Technical A rough guide to estimate the torque required to Digest No. 5, Steelfoist Inststute, Arlington, Va.,1974.
tighten anchor bolts is as follows:
- 3. Manual of Steel Construction Eighth Edstion, American Inststute ofSteel Constructson, Chscago, Ill.,1980.
Torque = KPD
- 4. Design Handbook-Precast Prestressed Concrete Second where K u 0.2 for oily threads Edstson, Precast Concrete Institute, Chicago, Ill.,1974 P = desired pretension in bc!:.
- 5. Uniform Building Code InternationalConferencrofBuilding D = diameter of bolt Officials, Whsuier Cat,1979.
- 6. Fisher,J. W.and].H. A.Struik Guide to De<ign Criteria Shown below is the calculation to :ighten a 2-in. dia.
for Bolted and Rivetedjoints John Wiley & Sons,Nezu Fork, A36 anchor bolt to F/2 or 18,000 psi.
197f.
K = 0.2 BIBLIOGRAPHY P = 0.5 x 36000 x 3.14 = 56,520 lbs Anchor Bolts D = 2 in.
Ardshardjo, R. and L. Soltis Combined Shear and Tension on Grouted Base Details AISCEngsneeringfournal, Vol.16, Tor 9ue =
= 1900 lb-ft No.1,1979,pp.23-26.
12 Canard, Richard T. Tests of Grouted Anchor Bolts in Tension and Shear ACI/ournal, Sept.1969,pp. 725-728.
Depending upon the steel erector, the engineer may y,y,ksns, N. Af., D. Afischell, and C. W. Roeder Moment -
- find that, rather that. specifying a torque for the in-Resisting Connections for Mixed Construction AISCEngi.
stallaiion of large anchor bolts, the erector may only neering./ournal, Vol.17, No.1,1980,pp.1-10.
require the desired bolt load. Many steel crectors prefer Kharod, U.f. Anchor Bolt Design for Shear and Tension AISC to tension heavy anchor bolts by using a hydraulicjack.
Engineeringfournal, Vol.17, No.1,1980,pp. 22-23.
In this way the preload can be directly applied to the AlcAfackin, P. J., R. C. Stutter and/. W. Msher Headed Steel bolt.
Anchors Under Combined Loading AISC Engineering fournal Vol.10, No. 2,1973,pp. 43-52.
Fatigue-In situations where the anchor bolts are Oligaard,f. C., R. C. Slutterandf. W. Fisher ShearStrength subjected to fatigue loading in tension, special precautions of Stud Connectors in Lightweight and Normal Weight must be taken. Assured pretension in the bolts is important; Concrete A/SC Engineering fournal, Vol. 8, No. 2,1971, h: wever, the usual procedures for tensioning bolts in pp. 55-64.
steel-to steeljoints are inapplicable or highly unreliable Shoup. T. E. and R. C. Singleton Headed Concrete Anchors
' in anchor bolt applications. This is especially true of the A C/ fou rn al, Sep t., 1963, pp. 1229-1235.
i
- turn-of-nut procedure. The author suggests if net tensile S i/cr, H. Dessgn of Base Plates and Anchor Bolts with S,mple stresses are kept to low levels (6-8 ksi), fatigue problems Assumptions Civst Engineering, April,1966,p. 63.
should not occur. However, if the anchor bolts are not 3,,,pi,,,,
tightened umformly, then the assumed equahty of loading DeWolf,/. T.andE. F.Serisley Column Base Plates with Axial among the bolts may not be true and fatigue problems can loads and Moments ASCE/ournaloftheStructuralDwinon, 1
i result. In fati;;ue situations, the designer should specify that Vol.106, ST 11, Nov.1980,pp. 2167-2184.
gli of the anchor bolts be pretensioned to at least a magni-Afaitra, N. Graphical Aid for Design of Base Plate Subjected tude which exceeds the applied design loading, and use of to Moment AISC Engincenng fournal, Vol 15, No. 2,1978, a detail which precludes reliance on natural bond. Further, pp. 50-53.
89 DGD OURGA i 1931
. n.
5 58
- alt Spenin atwn :Ellet t we : i i &
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.- mc h.
of is 1.23.3 Planing of Edges tu Planing or tinishing ot -heared or t hermally cut edge-of plate-or -hape-w ill not he required unless -pecifically ca!!ed for on t he draw me-or included m a stipulated edge preparation for welding.
P ',
1.23.4 Riveted and Bolted Construction-Holes 1.23.4.1 The maximum sizes of holes for rivets and bolts shall be a3 stipu-hi lated in Table L214. except that larger holes. required for tolerance on location or or anchor bolts in concrete foundations, may be used in column base detail, I.
1.23.4.2 Standard holes shall ne provided in member-to-member connec-tions, unless oversized short-slotted or long--lotted holes in bolted connections are approved by the designer. Oversized and slotted holes shall not he used in
]
riseted connections.
d If the thickness of the materialis not greater than the nominal diameter of to the rivet or bolt rius 4-inch, the holes may be punched. If the thickness of the 1
material is greater than the nominal diameter of the rivet or bolt plus ' -inch. the holes shall be either drilled from the solid or sub-punched and reamed. The die y'
__m for all sub-punched holes. and the drill for all sub-drilled holes. shall be at least f nch smaller than the nominal diameter af the rivet or bolt. Holes in A514
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steel plates over Vinch thick shall be drilled.
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1.23.4.3 Oversized holes may be used in any or M plies of friction-type y'
( f connections. but they shall not be used in bearing-type t 'nnections. Hardened
)
washers shall be installed over oversized holes in an outer ply.
,p g
as 1.23.4.4 Short-slotted holes may be used in any or all plies of friction type L
or bearing-type connections. The slot.s may be used without regard to direction H
l if loading in friction type connections. but the length shall be normal to t he di-ni rection of the load in bearing-type connections. Washers shall be installed over a-P short-slotted holes in an outer ply; when highatrength bolts are used. such
,,'t wa3hers 3 hall be hardened.
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- 5 49 ttachment H 1.15.11 High-Strength Bolts (in Friction-Type Connections)in Combination with Rivets In new work and in making alterations, rivets and high-strength bolts. in-stalled in accordance with the provisions of Sect.1.16.1 as friction-type connec-tions, may be considered as sharing the stresses resulting from dead and live loads.
1.15.12 Field Connections Rivets, high-strength bolts, or welds shall be used for the following connec-tions:
Column splices in all tier structures 200 feet or more in height.
Columi. splices in tier structures 100 to 200 feet in height, if the least horizontal dimension is less than 40 percent of the height.
Column splices in tier structures less than 100 feet in height,if the least horizontal dimension is less than 25 percent of the height.
1 Connections of all beams and girders to columns and of any other beams and girders on which the bracing of coiumns is dependent, in structures over 125 feet in height.
In all structures carrying cranes of over 5-ton capacity: roof-truss splices and connections of trusses to columns. column sphces, column i
bracing. knee braces, and crane supports.
Connettions for supports of running machinery. or of other live loads which produce impact or reversal of stress.
Any other connectior,s stipulated on the design plans.
~
In all other cases field connections may be made 4vith A307 bolts.
,]
For the purpose of this Section. the height of a tier structure shall be taken l
as the vertical distance from the curb level to the highest point of the roof beams
,a
- 7 in the case of flat roofs. or to the mean height of the gable in the case of roofs having d
a rise of more than 2% in 12. Where the curb level has not been established, or 5
where the structure does not adjoin a street, the mean level of the adjoining land kg Q -1
.[
i the height of structure.
Q hk%. w--
N shall be used instead of curb level. Penthouses may be excluded in computing GT 2
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SECTION 1.16 RIVETS AND BOLTS mm
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1.16.1 High-Strength Bolts g
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1 Except as otherwise provided in this Specification, use of high-strength bolts ge
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- d ASTM A325 or AM Bolts, latest edition, as approved by the Research Council i i
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h; b 5 IN 7
't on Riveted and Bolted Structural Joints.
7 If required to be tightened to more than 50 percent of their mmimum specified I h. N 5ME t(nsile strength. ASTM A 449 bolts in tension and bearing-type shear connections p g' shall have a hardened washer installed under the bolt head, and the nut.s shall meet the requirements of ASTM A325.
1.16.2 Effective Bearing Area
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The effective bearing area of rivets and bolts shall be the diamrter multiplied l
i by the length in bearing. except that for countersunk rivets and bolts !;. the depth of the countersink shall be deducted.
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'4.1. TYPES OF FASTENERS Fig. 4.1.1. Types or fauensts.
Every structure is an assemblage:of individual parts or members for ultimate strength;or as bearing type, where bearing of the bolt shank which must bc fastened together..usually ai the ends of its members, by against the hale is the basis for ultimate strength.
srm:means. One such meaniis welding which is treated in Chapter 5.
installation of these bolts may be either with calibrated torque Thecther is bolting and,in a few isolated cases, riveting. This chapter wrenches,or inure emumonly with any ordinary wrench using the " turn-is primarily concerned with bolting; in particular, high-strength bolts, of the-nut" method. The latter method involves making an additional liigh-strength bolts have for the most part replaced rivcts as the principal angular turn of the nut starting from the snug position, means of making nonwclded connections. IlowcVer, for completeness a For many years rivers were the accepted means of connect.ing brief description of the other fasteners, including rivets and unfinished Itinas.
Undriven machine bolts,is given.
members but in recent years have become virtually obsolete.
rivets are formed from bar sicci, a cylindrical shaft with a head formed on one end, as shown in Fig. 4.1.la. Rivet,stect is a mild carbon steel liigh-Strength Ilotts. The two basic types of high-strength boils are designated by ASTM as M02 Grade I (F, - 28 ksi) and Grade 2 (F,.
designated by ASTM as A325'and A490, the material properties of which 38 ksi).with the minimum specified yictd strengths based on bar stock a are discussed in Chapter 2. These bohs are heavy hexagon-head bolts, r lied. The forming of undriven rivets and the driving of rivets cause used with heavy semifmished hexagon nuts, as shown in Fig. 4.1.lb. The changes in the mechanical properties.
threaded portion is shorter than for bolts in nonstructural applications, The method of installation is essentially that of heating the rivet to a end may be cut or rolled. A325 bohs are of heat-treated medium carbon light cherry red color, inserting it into a hole und then applying pressure steel having an approximale yield strength of 81 to 92 ksi depending on 10 the preformed head while at the samp time squeezing the plain en diameter. A490 bolts are also heat-treated but arc of alloy stect having an the rivet to form a rounded head. During this process the shank of the '
apprenimate. yield strength of 115 to 130 ksi depending on diamcier.
rivet c mpletely or nearly fills the hole into which it had been inserted.
liigh-strength bolts range in diameter from '4 to l'4-in. The most Upon cooling, the rivet shrinks, thereby providing a clamping force.
ccmmon diameters used in building construction are 3/4 in, and 7/8 in.,
II wever,the amount of clamping produced by the cooling of the rivet whereas the most com' mon sizes in bridge design are 7/8 in. and I in.
varies from rivet to rivet and therefore cannot be counted on in design '
liigh-strength bolts are tightened to develop high tensile stress in calculations. Rivets may also be installed cold but then they do not de-
.vcl p the clamping force since they do not shrink after driving, them which results in a predictable clamping force on the joint.
The actu:1 transfer of service loads through a joint is therefore, due to the hese bolts are made from low carbon stect, designated fricti:n developed in the pieces being joined. Joints containing high-5 nn ied B oh s.
jcj%.f.g as ASTM A307, and are.the'icast expensive type of boli. They strength bolts are designed either as friction type, where slip is the basis H
- l
]
?hM
1934. Daths and Dateman c:ncluded that b:lts,with a minim 85.S ructural Fqt:ncrs Q[
strength cf 54 ksi c:uld b r;1iid en to prevent slippage cf th h waver,p'roduce theleast expensive c6nnection since many mtre miy be j;-; -
Earts. Follow-uE tests by Wilson and Thomas'subst'anti e th M ihe r:q ir:d in a particular connection. Their primary use is,n light struc.,
W" i
ht @se@ Ms Mer b h-rep
. E tures, secondary or bracing members, platforms, catwalks, purlins girls holes in which they were inserted had~ fat,gue strengths equa i '
small trusses an'd simil;ir applications.in wh'ich the. loads are Erimaril d'
Y-C-
small rnd stat.ie in nature. Such. bolts are also used as tcmporary fitting
- E The next major step occured m 1947 with the formation of the Re up c:nnectors in cases where high-strength bolts, rivets, or weldin8 rnaY -
d on Riveted and Dolted Structural Joints. Tins organus-
.e search Coune.
be the permanent means of connection. Unfinished bolts are sometimes
. n began by using and extrapolaimg information from stud es i
c:lled crmmon, machine, or.r'ough. bolts and may come with squuro-joints;in particular, the extensive annotated Dibliography by D heads. and square nuts.
com'pleted in 1956,was used. From this beginning, the flesea has continued to organize and sponsor research on high-strength Turned Ilolts.- These practically obsntese bolts are maEhined from hexag-connections,and issue specifications at. intervals on the basis of re onalstock to much closer tolerances (about %. in.) than unfinished bolts; findings.
This type of-bolt was primasily used in connections which required close-The American Railway Engineering Association (AREA)also beceme clitting bolts in drilled holes, such as in riveted construction-where it was interested in 1948 and initiated studies on the use of high-strengt
.n:t p:ssible to drive satisfactory rivets. They are sometimes useful iri railroadInidge maintenance. In the same year the Association of Amer-shgmng mechan,ical equipment and structural members tvhich require pre-ican Itailroads initiated a number of fictd test installations confirmin case positioning. They are now (19711' rarely if ever used in ordinary adequacy of connections made with high-strength bolts.
structural connections, sincehigh strength bolts are better and cheaper.
Ily 1950 the concept of using high-strength bolts and a sum research and behavior was presented' to practising engineers and Rihbed Dolts. These bolts of ordinary rivet sicci which have a rounded fabrication industry. As the next step,in 1951 the Itescarch Council head and raised ribs parallel _to the shank were used for many years as an lished its first specifications, permitting the replacement of rivets w
.aitternative to rivets. The actual diameter of a given sire of ribbed bolt is bolts on a one-to-one basis. It was conservatively assumed that frictio slightly larger than the hole into which it is driven. In driving a ribbed transfer of the load was necessary in all joints under service load bolt, the bolt actually cuts into the edges around the hole producing a tions. The factor of safety ugainst slip was established at a high eno relatively tight lit. This type of bolt.was particularly useful in bearing level so that good fatigue resistance (i.e., no. slip under varying stress or connections and in connections which had stress reversals.
stress reversal consisting of many load cycles) was provided in ev A modern variation of the ribbed bolt is the interference-body bol, similar to or better than that shown by riveted joints.
shown in Fig. 4.1.lc which is of A325 bolt sicci and instead oflongitudinal In 1954 a revision was made in the spuifications to include the u ribs he -; ions around the shank as well as parallel to the shank. De.
flat washers on 1:20 sloping surfaces and to allow the use of impact cause of the serrations around the shank through the ribs, this bolt is often wrenches for installing high-strength bolts. Also, the 1954 revision per-called an interrupted-rib holt. Ribbed bolts were also dillicul't to drive mitted the surfaces in contact to be painted when the bolts were to create when several layers of plates were to be connected. The current high.
a bearing type connection;i.e., when the ultimate strength of the con strength A325 interference-body bolt may also be more. difficult to insert ti n was to be based on the bolt in bearing against the side of the hole.
In 1956 W. II. Munse summariicd bolt behavior and 8
thr ugh several plates;however,it is used when tight fit of the bolt in the heleis desired and it permits tightening by means of turning the nut with if high-strength bolts are to be as efficient and economical as pos aninitial tendon as high as practicable must be induced in the bol cut the simultaneous holding of the bolt head as may be required with smroth loose litting ordinary'A325 bolts.
1960 much additional research justified increasing the minimum bo gnized that the bearing-typc conisection was ordinarily an
.I ns n, re acceptable substitute for a rivetsd connection, and accepted th:in the 4.2. tilSTORICAL BACKGROUND OF HIGil.STRENGTil BOLTS h[.t.ryction with its strength based N..
tuay only be necessary when direct terision acts on' the bolts or wh CThe first experiments-indicating th'e possibility of using high-strength bolts i l-framed construction was reported by Datho and Dateman' in
& gyg,i ';.y 1
=-
,Ef Attachment J
$. 28 e AISC Specification (Effective i1/1/78) ance with Sect.1.5.6, the constants in the formulas listed in Table 1.6.3 shall be increased by %, but the coefficient applied to fu shall not be increased.
For A325 and A490 bolts used in friction. type connections, the maximum l
shear stress allowed by Table 1.5.2.1 shall be multiplied by the reduction factor
=
(1 - f,.13/T3), where /, is the average tensile stress due to a direct load applied to all of the bolts in a connection and T3 is the specified* pretension load of the I
bolt. When allowable stresses are increased for wind or seismic loads in accor.
dance with the provisions of Sect.1.5.6, the reduced allowable shear stress shall be increased by %.
t r
I TABLE 1.6.3 ALLOWABt.E TENStoN STRESS (Fr) FoR FASTENERS IN BEARING. TYPE CONNECT!oNS Threads Not Excluded Threads Excluded Description of Fastener from Shear Planes from Shear Planes f
9 lts o e 1%-in.
0.43F. - 1.8/, s 0.33F.
0.43F - 1.4/, s 0.33F.
diarneter J_--
- - -- a
__ -.s-22 A325 bolts 55 - 1.8/c s 44 55 - 1.4/y 5 44 M
i
-1 L c..
A490 bolts l
68 - 1.8/, 5 54 68 - 1.4/, 5 54 5~-t---M %'
y A502 Grade I rivets 30 - 1.3/y 5 23 f-b..
A502 Grades 2 and 3 rivets 38 - 1.3/, s 29 A307 bolts 26 - 1.8/, 5 20 we mm a
add thiliE
= ~
t EM I Ehk SECTION 1.7 3IE3tBERS AND CONNECTIONS SUBJECT TO g.4 ip f-
- -y l f
REPEATED VARINIION OF STRESS (FATIGUE)
)! n 2,
1 1.7.1 General ggn
?
Fatigue, as used in this Specification,is defined as the damage that may result 7
M-d l
1 in fracture after a sufficient number of 11uctuations of stress. Stress range is f
Q}' gje"3:%
./
a defined as the magnitude of these lluctuations. In the case of a stress reversal,
..k l
stress range shall be computed as the numerical sum of maximum repeated ter.sile i
and compressive stresses or the sum of maximum shearing stresses of opposite Byg direction at a given point, resulting from differing arrangements oflive load.
l Few members or connections in conventional buildings need to be designed for fatigue, since most load changes in such structures occur only a small nurr.ber 4.
of times or produce only minor stress fluctuations. The occurrence of full design i
BRM i TJEsll l
wind or earthquake loads is too infrequent to warrant consideration in fatigue ppe
_ '_7 E
]
design. However, crane runways and supporting structures for machinery and l
(
{
equipment are often subject to fatigue loading conditions.
i
- See ".\\linimum Bolt Tension" values. Table 1.23.5.
l l
Attachment K j
i 4 125 SUGGESTED DETAILS t
Column base plates A
e.-
eq s,
.Sh00 Weld p
A it.4p of bolt U
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Base plate detailed and snipped toose when required 3l 1
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y Notes 1
Hole sizes 'or anchor bolts are normally made oversite to facilitate erecSon as follows I
Bolts % to 1 :
5 s ' oversize Bolts 1 to 2~:
' r' oversize Bolts over 2~ ; - 1 ~ Oversile i
The stabrlity of a Co!unn etM 'f s 'oading should be 2
Considered at ad stages of erection and its base designed accordinql / 'or anchors ar,0 base plate 1
AM(QdkN f *4 s t r r v4
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3 1
E0tsE'E3 U%hL
'84 OCT 29 A11:48 UNITED STATES OF AMERICA
.E. __
a.
NUCLEAR REGULATORY COMMISSION Eh" 00 M }l BEFORE THE ATOMIC SAFETY AND LICENSING BOARD In the Matter of
)
)
Docket Nos. 50-445 and TEXAS UTILITIES ELECTRIC
)
50-446 COMPANY, et al.
)
~ ~ ~ ~ ~
)
(Application for (Comanche Peak Steam Electric
)
Operating Licenses)
Station, Units 1 and 2)
)
CERTIFICATE OF SERVICE I hereby certify that copies of " Applicants' Reply to (1) CASE's Answer to Applicants' Motion for Summary Disposition Regarding the Effects of Gaps and (2) Board Chairman's
" Preliminary Views" Regarding Additional Pleadings", in the above-captioned matter was served upon the following persons by express delivery (*), or deposit.in the United States mail, first class, postage prepaid, this 26rd day of October, 1984, or by hand delivery (**) on the 29th day of October, 1984.
- Peter B.
Bloch, Esq.
Chairman, Atomic Safety and Chairman, Atomic Safety and Licensing Appeal Panel Licensing Board U.S.
Nuclear Regulatory U.S.
Nuclear Regulatory Commission commission Washington, D.C.
20555 Washington, D.C.
20555 Mr. William L. Clements
- Dr. Walter H. Jordan Docketing & Service Branch 881 West Outer Drive U.S. Nuclear Regulatory Oak Ridge, Tcnnessee 37830 Commission Washington, D.C.
20555
- Dr. Kenneth A.
McCollom Dean, Division of Engineering
- Stuart A. Treby, Esq.
Architecture and Technology Office of the Executive Oklahoma State University Legal Director Stillwater, Oklahoma 74074 U.S.
Nuclear Regulatory Commission Chairman, Atomic Safety 7735 Old Georgetown Road and Licensing Board Panel Room 10117 U.S.
Nuclear Regulatory Bethesda, Maryland 20814 Commission Washington, D.C.
20555
N l
, Robert D. Martin Elizabeth B.
Johnson Regional Administrator, Oak Ridge National Laboratory Region IV Post Office Box X U.S.
Nuclear Regulatory Building 3500 Commission Oak Ridge, Tennessee 37830
'611 Ryan Plaza Drive Suite 1000 Mrs. Juanita Ellis Arlington, Texas 76011 President, CASE 1426 South Polk Street Renea Hicks, Esq.
Dallas, Texas 75224 Assistant Attorney General Environmental Protection Lanny A.
Sinkin Division 114 W.
7th Street P.O. Box 12548 Suite 220 Capitol Station Austin, Texas 78701 Austin, Texas 78711 uh) u.- f'
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J. W William A.
Horin cc:
John W.
Beck Robert Wooldridge, Esq.