ML20004E121

Paper Entitled Blasting Vibration Limits on Freshly Placed (Green) Concrete, Presented at ASCE 1980 Annual Convention & Exposition Session on Const of Nuclear Facilities in Hollywood,Fl

ML20004E121
Person / Time
Site:	Limerick
Issue date:	10/29/1980
From:	Desai A, Hulshizer A UNITED ENGINEERS & CONSTRUCTORS, INC.
To:
Shared Package
ML20004E120	List: ML20004E119 ML20004E121
References
NUDOCS 8106110185
Download: ML20004E121 (15)

Text

O This Paper for Presentation at the ASCE 1980 ANNUAL CONVENTION AND EXPOSITION

• e-~ lon on Construction of Nuclear Facilities October 29, 1980 Hollywood, Florida

" BLASTING VIBRATION LIMITS ON FRESHLY PLACED (GREEN) CONCRETE" By Allen J. Hulshizer, Supervising Structural Engineer United Engineers and Constructors Inc.

Ashok J. Desai, Structural Engineer United Engineers and Constructors Inc.

!6106 310 &

s s

-m,-

1,.

" BLASTING VIBRATION LIMITS ON FRESHLY PLACED (GREEN) CONCRETE" 1

By Allen J. Hulshizer, F. ASCE and Ashok J. Desai, M. ASCE INTRODUCTION This paper summarizes the results of an extensive program carried on for the Seabrook Nuclear Station to increase blast-vibration limits for freshly placed concrete (" Green") without detrimental effect on its strength properties. In the absence of available data, a test program was carried out in both the laboratory and field to study a wide range of variables to insure the enveloping of various combinations of vibration characteristics and concrete ages.

Ccnclusions from the program have resulted in significantly raising previously utilized green concrete re-vibration limits while still pro-viding conservative margins with respect to any effect on design re-quirements. These "new" vibration limits allow for more productive blasting work during concurrent concreting operations providing economies in both cost and schedule.

l BACKGROUND Due to long and various starting delays, it became necessary to re-schedule excavation and concrete work concurrently in order to recover schedule losses. Blast vibration specification limits relating to green concrete, which did not hamper the previously time independent blasting and concreting efforts, became very restrictive and would have resulted in serious construction delays if necessarily maintained.

The original Seabrook specification blast vibration limits for green concrete was taken from work done for the Maine Yankee Atomic Power Plant, Wiscasset, Maine (1), herein after referred to as the j

"Weston Report." Apparently, these values have been used for other nuclear power plants in this country.

Examination of the Weston Report indicated that the parameters suitable to obtain vibration limits for the initial intended purposes did not establish conclusive limits and an apparent increase in these values could be substantiated.

DEFINIIIONS Green concrete, as used within this paper, refers to concrete having an age within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> after placement.

The term re-vibration or vibration of green concrete utilized with-in this paper refers to the vibrating of consolidated ' concrete during its early curing stage and does not refer to re-vibrating of fresh concrete to improve its properties.

Supervising Structural Engineer, United Engineers and Constructors Inc, Phila., PA.

2Structural Engineer, United Engineers and Constructors Inc, Phila., PA.

l 1

I I

j REVIEW OF HISTORICAL DATA With the knowledge that green concrete vibration limits were not unique to the Seabrook work and that some margin was likely in the 4

original Weston Report limits, a literature and industry practice search was undertaken to find quantitative data that would substantiate new higher vibration limits.

i A survey was made of nuclear plants constructed on rock sites to ascertain what blast vibration limits were imposed to insure " safe" concrete work. A sununary of the values as reported is given in Table 1.

Apart from vibration limits imposed to prevent tripping of on site l

operating nuclear plants, wide variations in specified peak particle velocities were found. The data used to establish the green concrete vibration limits was not available (unless based on the Weston Report) and in all cases the limiting values would have been restrictive to the i

Seabrook construction operation.

In addition to industry and literature searches, organization such as the American Concrete Institute, Portland Cement Association, Bureau of Reclaimation, blasting powder companies, cement and concrete com-l panies and other sources even remotely related to the problem were con-tacted. An index of more salient related publications is provided in the Compendium.

Much of the experimental work and studies found were associated with consolidation during concrete placement and other information on re-vibrating green concrete required various degrees of extrapolation to obtain useful parameters.

It was, therefore, determined that test-ing work should be undertaken to obtain factual information specifical-

'ly identified with raising green concrete re-vibration limits.

Of general note is that the normally cited blast damage criteria limits of 2 inches /sec. and lower appears to be established basically to protect masonry and plastered structures sud to avoid public and legal struggles and does not directly reiste itself to construction l

efforts removed from the public which involve engineered structures i

built of reinforced concrete.

(See Compendium, Reference 1, Chapter 7, Paragraph 7-3, pgs. 7-5 to 7-10.)

SEABROOK TEST PROGRAM The Seabrook testing program was developed to evaluate what effect blast induced vibrations on green concrete would have on structural properties of concrete with the goal of obtaining the critical damage limits. Concrete properties deemed most significant to structural performance and durability were that of compressive, shear and rein-forcing bond strength. Since reinforcer'. concrete is basically designed as a " cracked section", no effort was made to test or evaluate plain concrete flexural performance.

Because of the strong demand to have information related to actual conditions, one phase of the program was conducted in the field utiliz-ing explosive blasting under controlled, monitored conditions. The i

other phase involved laboratory work which economically allowed for a more extensive and more contro?. led and monitored testing program but one which could be easily correlated with the field work and which could also be used to evaluate the effects of other than blast type vibrations (i.e.:

more regular patterns). Since it is generally recognized that d.

t-T.

-eeme

-epgg--gm.-e..-e>gy-.+y.vm---wgyn yy,e-g<ay.

g..

,.m9gggp+y,_gg-g, gg,99 m,94q.3wgy,w,y y--

yp gr yy=eMe -p-v yy311'yMT t'T'T TTM"9'"'-4

PM-W'e'NMW*NWT' PW 7 v

"-V'9"4--TM*-f"4"*

tha first 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> of etnersta sse time will raprec nt tha most criti-cal period, the program limited its study to concrete vibrated at various intervals within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> after concrete placement.

The entire test program was carried out under fully implemented Quality Assurance procedures.

The following is a summary of the number of control and test sam-pies utilized:

Cylinder Bond Compression Shear & Bond Pull Out Test Beam Test Test Cores Field 120 140 255 31 92 Laboratory 258 Total 378 140 347 31 FIELD TEST PROGRAM Essentially the fiell test program was comprised of casting various types of concrete specimens and subjecting them, at specified concrete ages, to blast vibrations of differing magnitudes which were measured and recorded. Control (un-vibrated) specimens were cast from the same concrete batches. Field work was carried out in areas remote to heavy construction traffic and basically free from other blast induced vi-brations so that the test vibrations introduced and monitored represent clean data free from background distortions. After the appropriate 7 or 25 day period had elaps ed, the vibrated and control specimens were load tested and results evaluated.

The field test program was divided into three areas, namely:

1.

Cylinder Test 2.

Beam Test 3.

Wall Test Field Cylinder Test Program This program consisted of casting standard 6x12 inch cylinders, l

subjecting them to blast vibrations (except for controls), curing the cylinders in accordance with ASTM C31 and then performing the standard l

ASTM C39 compressive load test. Reinforced concrete test pads were constructed on 20 foot (6.1 m) centers. Pads were founded on and an-chored to rock by means of resin type rock anchors. Pads were equipped with hold down bolts and apparatus to hold four concrete mold cylinders firmly in place during the blast. Provisions were also made to bolt dowr. a monitoring transducer on each pad and read reniotely at a central station.

(See Photograph No.1).

l l

A set of four cylinders were cast and rigidly f oxed to the test pad.

At the appropriate time the blast was detonated and the vibrations re-corded for each of the four pads. The cylinders were then protected and cured in place for 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> after which they were removed (along l

with the remotely cast control cylinders), cured in the testing labora-tory and compressive load tested after the 7 and 28 day curing time (two 7 day and two 28 day tests from each pad).

3 I

l

The effect of blast vibrations on tha cylindars wcs evaluttsd by normalizing the change in vibrated cylinder strengths by representing them as a percentage of increase or decrease in strength from that of the control cylinders and plotting the variation with respect to the i

experienced peak particle velocity. Comparatae plots of 7 and 28 day cylinder compressive tests are shown in Figures 1 and 2 respectively.

i l

As can be noted from the normalized test results plotted on Figures 1 and 2, no specific trend in the change of cylinder compressive strengths can be established since the relative variation in compres-l sive strength increases and/or decreases randomly for any given age or i

curing or magnitude of induced vibration. A further comparison of cor-l l

responding 7 and 28 day relative compressive test for a specific vibration level-concrete age datum point (i.e.:

cylinders subjected to the same blast vibrations) illustrates the fluctuating-oscillating changes in the concrete cylinder strengths for identically vibrated l

cylinders. The effect of differential curing time (7 days vs. 28 days) is considered to be of little consequences since no specific or general change in test values can be associated with the observed test results.

(i.e.:

Longer cure time did not apparently produce greater strength cylinders due to autogeneous healing which would offset any detrimental cracking effects produced by the induced vibrations. See Reference 3).

With respect to the magnitude of tha incrasae or decrease in cylin-der strengths it must be noted that the variations actually lie in a relatively tight band where 967. of the relative test values fall within a plus or minus 67. variation and 98% fall within a plus or minus 77.

variation. This range of variation is considered to be within an acceptable level of variation that occurs in cylinder testing.

I Field Beam Test Program Reinforced beams measuring 4 x 8 inches and three feet (0.91 m) long were selected in order to utilize a standard cylinder testing machine and flexural beam testing apparatus. A typical beam was de-signed and reinforced with one No. 6 bar. To precipitate a reinforcing bond failure it was necessary to minimize the embedded length to 4 l

l inches so as not to fail the 4 x 8 inch concrete section in shear.

Em-bedment length was controlled by installing plastic sleeves over the l

center portion of the reinforcing.

(Photograph No. 2) l The besa specimens were cast, vibrated and cured in similar fashion to that of the cylinders utilizing the same test pada (See photograph No. 3). Two beams were cast rr. each pad. Two test sets of two beams l

each were made for each cancrete age-vibration level datum point to be evaluated. One set was arranged so that the be.uns'long axes were aligned parallel to the direction to which the blast vibrations were originating and the other arranged with the beams' ions axes perpen-dicular to the originating vibration direction. This approach was taken to be sure that there was no variation in results occurring from phenon-enon relating to the difference between the blast wave propagation transverse to or along the axis of the beam. All beams were load tested 7 days after casting. Standard compressive cylinders were made to determine cylinder strength for analytical purposes.

Beams were tested per ASTM C293, center point loading. Due to the plastic sleeve the loading produced an early flexural crack in the beam center which did not effect its ultimate load capacity. As loading was continued, the beam would ultimately fail by:

i 4

lL.- - - - -.. -. - -.. - - - -. - - -

j.

1 Bond failure of ths 4 inch (102 nun) rsbre anchsregs withcut splitting or shearing of the beam and sometimes followed by a I

shear failure.

l I

2 Bond failure in the anchorage zone resulting in splitting off concrete adjacent to the anchorage, usually followed' imediate-ly by a shear failure of the beam. (Photograph 2)

The " Ultimate" load was recorded as the peak load capacity of the l

member (which occurred just prior to failure).

Since the mode of failure and the corresponding failure load varied, it was not possible to make a direct comparison between vibrated and un-vibrated (control) beams as was done with the bla.c vibrated cylinders.

i An alternate means of evaluation was derived by calculating the safety factor between the " ultimate design capacity" and that of the " actual ultimate test capacity". The ultimate beam design capacity was deter-i mined from ACI 318-77 provisions considering unconfined bond anchorage values and actual cylinder test values of the same age and material utilized in the beam.

A summary of the test values is given in Table 2.

No signs or features were visible in the vibrated or unvibrated samples tested that could be related in any way to a less than sound concrete product.

l Field Wall Test Program The final stage in the field tasting program was to " simulate a typical" concrete section and subject it to blasting and study the i

effects.

l Five walls were constructed, four test walls were subjected to blasting and one' control kept free of vibrations. Each wall was made up of two - 2 feet. (0.61 m) wide by 8 foot high by 8 foot (2.44 m) long walls arranged as a cruciform to introduce longitudinal and trans-verse blast wave effects. Walls were typically reinforced throughout with #6 rebars at 12 inches (305 num) on centers, each way.

i Bond test dowels,,#8 rebars, were placed into the walls at varying locations and depths. Plastic sleeves were used over the bars to con-trol the test zone location and provide a 10 inch (254 set) embedmont length for pull testing of bond values (See photograph No. 6).

Four-hour and fourteen-hour green concrete ages were chosen as suf-ficient to represent the varying spectrum of concrete set time enarac-teristics.

Each of the walls to be vibrated were instrumented at the foundatims level and on the top of the wall at the intersection. The two closest walls to the blast also had a transducer located at the mid-height in-tersection. The higher transducers provided information relative to amplifications through the wall system.

Twenty eight days after casting the walls, pulling of the #8 test Each dowels commenced, utilizing a 30 ton (27,210 kg) hollow ram jack.

bar was 1saded until it began to pull out. The bond failure load was determined to be the load at which continued pumping initially did not result in' an increase in load. At this point, verification of movement 5

I

\\

unu

-p i n

• o.v.. u m.e.m.e.i.,e,

. 1 I

>7

,','[ g - c,

s a ycJa..taaef cond4WC'Oe ldt1

• .1, s

6

~cm

.c. e. one==<=,e um n.co

.o.n ii.u i..u l

l

,e e

[

'.,, gg.,.

v

..- m

.c mc

...i.,

,e

,h.

?/ *.i m

act='

e u.'..::,

in in su iui*

i.

..n>

Photograph 1 a n==ce i.i se re FIELD CYLINDER TEST PAD

.et-r oor ou e.m aio s ie es i n i=*

t.n ese. -.v.m s o,e c s r e,

Ik:L.no esma, s. I Gaseet le fe. inne of sies.nesa 6 I Laeme esees.s 01 eseet ip ese,-y.- _

t : pe,eene + m. be 0.3 et.ee.n ite.em,13 none j;

i.i - - -. - e e.

If b.ane =anones. se O eiese.ftoe F. set i.i -..e.-.~e.e.

.en.s.-.

f 6 5 :m. samune..as i.em sses si.e Memas a

ONE.sCsi. s.am T*\\

. gjff'

'\\

$dh Wh: -

O.

)$g-a.e3gk%* E%?g$

- ~ m e. -

< s.

e.:.?d'4 w m.a.cu.l s,.n,.s.co s{

as cmc n= =.rcts nsi r

vawn = ac=we

.crum,cuc ;

==a

.c t, cue.

.c i i.as -.

'au

. u l s?. =u l s?

Photograph 2 jan g

FIELD BEAM SPECIMEN

..s en in

i. n l in ' au I 23 on j :. l.o.

.AFTER LOAD TESI j..

i st un us

.. ! in en !

= i e i.

g

- l su

.ut u. l. o.

.. o ll ion en I so g

o.i

.a

. I i.i e n l au on ag,w.. wwd I-su i r.

i.n l in om ' u.

a i.

yy i

t

--q 1

.i

...... i a,,

c

i., j

..i u,

l e

ru i.

, 3 l

j os o i.

so u.

y e

m

==l ni j ia n, in o o.

23 e i.

=

aan sa i

J.

.,a

.n en l ia a

i e.

2n

.=.!

iu s-

.,,,.m.

va 1

..- ~

i.

> e z

,d

, - ~ '.

vien.no i.u

. I su air e

' E r,x 3

m 5^"""'

cc,,.e.

. j i rr

=

5.5 m

i A,fs-cocaat ano. visa.no e..eas en se..s 1

Photograph 3 FIELD BEAM TEST PAD P00R ORIGML

.6

e 4

4 was mada by mensuring ths "new" isngth of tha extendid bar. Esssn-tially, the 10 inch embedment of the #8 bar was sufficient to develop a i

stress level in the average bar of 66,667 ksi (459.3 M Pa).

In a few cases, the bars broke at a small notch put in the bar to facilitate jacking prior to breaking the bond.

3 Results of the pull-out values were very close and no significant difference can be observed between the vibrated and unvibrated values.

l A comparison was made between the ACI 318-77 confined anchorage values (for "other" bars) and the " actual" bond failure loads. A summary of i

these and other values are given in Table 3.

Note, that the average unconfined bond safety factor from the beam test (Table 2) and the con-fined bond safety factor from the wall test are reasonably ci,s,e, con-firming a considerable margin of safety for bond values without any consideration for " top bar" allowances.

After completing the bond test, 4 inch (101.6 aun) dia. cores were taken from each of the walls. Visual examination indicated no signs of flaws or deterioration. Cores were load tested asi gave results com-patible with what would be expected from the loaa testing of cores.

Finally, one of the walls was blasted loose from the rock and pushed out of the way by bu11 dozing (See photograph No. 7).

Examination of this wall externally and within the core holes did not reveal any blast induced cracking which would have been exaggerated by the extreme hardling.

LABORATORY TEST PROGRAM Essentially, the laboratory phase of the testing program was com-prised of, casting cylinders and bond pull-out specimens and subjecting them, at specified concrete ages, to various fixed frequencies and i

velocities by means of a shaker. table. All specimens were well moni-tored and vibration characteristics respectively recorded. Control (un-vibrated) specimens were cast from the same concrete batches. After the appropriate 7 or 28 day period had elapsed, the vibrated and control specimens were load tested and results evaluated.

All testing work, except for load testing of the specimens, was carried out by The Franklin Institute Rer,earch Laboratories, utilizing the General Electric Company Space Center facilities at Valley Forge, Pennsylvania.

Nominal curing time from specimen casting to vibration of 3, 6, 12 and 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> was used.

The velocities and frequencies (and associated accelerations) given in the following Table were utilized. Test frequencies were chosen from the predominate frequencies associated with maximum velocities ob-served from the site blast monitoring records.

(Table on next page.)

Vibrations were induced such that the profile of vibration had a rise and fall' time of 0.5 I 0.3 seconds and remained at the peak 1&el for 5.0 t 0.5 seconds. The specimens were subjected to excitation ir.

one horizontal axis through the base. Vibration profiles were recorded for each of the three perpendicular axes.

A C150 shaker manufactured by M.B. Electronics, a Division of Textron' Electronics, Inc.,was used to energize the shaker table.

7

ped 3 PARTCLE VELOCITY IN INCHES /SEC. MECSURED AT THE CYLINOER

-- 14 0 e

0 y

INDICATES NOMINAL TIME AT WMCM CYLINDERS WERE SUBJECTED TO BLAST VIBRATIONS

--10 0

/

j' pP*.Ng /

80 g:A

<f,,,k,.

0 i

.s

\\

\\*N s.

N

% *? e-o-

h.

V, 40

-40

-40

-20 0

+2 0 40 40 40

% VARIATION IN C(MAPRESSivE STRENGTM WITH RESPECT TO UNvi8AATED CC*dTROL CYtlNDER FIGURE 1 RELATIVE CHANGE IN COMPRESSIVE STRENGTH OF CONCRETE CYLINDERS VIBRATED BY BLASTING. CURED T DAYS PEAM PARTICLE VELOCITV lN INCHES /SEC. MEASURED AT THE CyLINOER

-- 14 0 e,

12 0 INDICATES NOMINAL TIME e,

AT WHICM CYLINDERS WERE SUBJECTED TO BLAST vtBRATIONS (j

,7 r '"

\\

s' l

>(*.g

.. 0.,l

\\

/>

l x

y i N.N.$' 0

'N

,. e '

a

(.

0 0

Q-A

~. _. f-W~,N

.-r e

a t

40

-40

-40

-20 0

• 20

+4 0 40

+6 0

% VARIATIOrd IN COMPRES$1vE STRENGTH wiTH RESPECT TO UNvl8 RATED CONTROL CYLINOER RELATIVE CHANGE IN COMPRESSIVE STRENGTH OF CONCRETE CYLINDERS VIBRATED BY BLASTING - CUREO 28 DAYS P00R ORGM 4

a l

IN E

C EASI.R O Q

AT THE CYUNDER

\\

T C

E$ RE

%~

s*#TJ,A:?.T.u' "-

/

\\;

'y

/

N

/

4-N

\\,/

-- 40 ss y

-40 l

l l

l

/

.N

/

r

/,

.M t

' " " 20 N

b

-12 0 10 0

-40

-40

-A 0

-20 0

20

-40 40 40 10 0 12 0

% vansATION IN CouemEssivE SimENGTH wiTH RESMCT TO UNV10AATED CONTROL CYUNCER FIGURE 3 of CONCRE E YUNDE v BRA D wi M FRE E Y OF 100 M2 CURED 20 QAYS

-(

l a

3

- as n -,.g s.

fy7:' c m.

~

i 1,.:.

'g

?[f M

F"-

y

.i.

'i m w i

4.. y '

Photograph 4 Photograph 5 CYLINDER FIXTURE FOR VIBRATING INSERTING " GREEN" CONCRETE GREEN CONCRETE MOLDS INIO CYLINDER FIXTURE MOLDS.IN LABORATORY ON SHAKER TABLE P00R R G E!.

9

IABORATORY TEST VELOCITIES AND FREQUENCIES (AND ASSOCIATED ACCELERATIONS)

FREQUENCY MAXIMUM PEAK PARTICLE ACCELERATION IN g j

50 hz 0.83 1.66 3.3 6.6 13.2 100 hz 1.66 3.3 6.6 13.2 26.4 150 hz 2.5 5.0 10.0 20.0 30.0 PEAK PARTICLE VELOCITY 1

2 4

8 12 16 INCHES /SEC.

l One Inch =25.4 mm The energy input into the laboratory vibrated specimens is consid-ered to be comparatively more severe due to the longer period the spec-L=en is subjected to the induced vibration.

Laborarary Cylinder Test Program This program consisted of casting standard 6 X 12 inch (152.4 X 304.8 mm) cylinders and subjecting a group of 4 cylinders at a time to the selected vibrations by means of a rigid steel fixture fastened to the shaker table.

(See photog.aph Nos. 4 and 5.) Cylind1rs were cast, cured and compressive load tested in accordance with ASTM C31 and C39.

Control cylinders (unvibrated) were cast from respective concrete batches.

Af ter the appropriate 7 or 28 day curing time, 2 cylinders from each group were load tested along with control specimens. The effect of vi-bration was evaluated in the same manner as the Field Pro

• gram cylinders by normalizing the change in vibrated cylinder strengths by representing them as a percentage of increase or decrease in strength from that of the control cylinders and plotting the variation with respect to the experienced peak particle velocity.

A representative plot is shown in Figure 3 and a table of test values, irrespective of vibration levels or green concrete age is given in Table 5 Results of the laboratory cylinder test program were essentially the same as the field cylinder program.

Specifically, no specific trend can be established in the change of cylinder strength with respect to any of the vibration levels introduced for any of the green concrete ages tested.

Laboratory Pull-Out Test Program This program consisted of casting, curing and testing pull-out sam-ples in accordance with ASTM C234 (152.4 mm) cubes with a 3 foot Pull-out specimens were 6 inch tending to the specimen bottom. (0.91 m) long, #6 reinforcing bar ex-Specimens were cast in specially made molds, structurally strong enough to permit direct attachment to the shaker table.

Specimens were subjected to the same basic age-vibration levels as that of the cylinders and tested 7 and 28 days after casting.

10

Dus to tha nominal 30 inch (762 mm) cxten=4 of tha #6 rainforcing bar, a whipping action was introduced during the shaking operation even though the top of the bar was relatively secured to the casting mold.

This behavior created an added severity to the reinforcing bar bonding capability.

Although the ASTM C234 is to evaluate concrete strengths by com-parate bond failures (not necessarily related to ACI 318 design values),

the test did confirm information relative to the effect of the induced vibration on bonding characteristics.

Basically, all pull-out specimens failed by splitting of the con-crete block prior to achieving a bond failure. However, the load, developed by the 6 inch (152.4 mm) embedment of the #6 reinfor'cing bar was, again, significantly above the ultimate anchorage load calculated from ACI 318-77 for unconfined bars.

Values, irrespective of the green age or vibration level, are given in Table 4 Essentially no reduction in concrete strength or bond capacity can be recognized as a result of the vibrations introduced to the various green concrete ages.

SUMMARY

1.

Due to space limitations, detailed discussions of test and evalua-tion work and data, presentation has been greatly shortened. Data has been summarized in an attempt to provide sufficient overall information to. establish the validity of the work.

2.

Test work was done for the mogt part with readily available re-sources, and there was no attempt to pursue a full scale research program outside the realms of establishing increased vibration levels for green concrete.

l 3.

Although the test program was aimed at finding a " critical" I

vibration intensity for green concrete, no vibration level was ever reached that could be associated with ultimate damage to the con-crete tested.

4 Although many specimens of various types were subjected to input velocities up to and in the range of 8 to 12 inches per second and some subjected to velocities aa high as 20 inches per second (l" =

25.4 mm), there has been no evidence to indicate that the re-vibrated green concrete tested would not structurally perform in accordance with its standard 28 day strength design values or would otherwise produce a less durable structure.

5.

Results of the test were used to re-establish green concrete blast vibration limits as given in Table 6.

The values listed are still conservative with respect to the test program results and even with respect to some of the " original Table 1" values. Prevision for an increase in blast vibration levels above the Table 6 values was treated on a case-by-case basis, but essentially the Table 6 values allowed reasonable excavation efforts without schedule difficulties.

6.

Bond test results indicate an appare.nt strong conservatism in the ACI-318-77 anchorage provisions. This conservatism should be looked 11

ct with respect to eliminating ths 1.4 factor for horizonta?cwall laps which are currently identified as " top bars." This reduction in horizontal lap length would serve to reduce added congestion in heavily reinforced walls apart from any savings in reduced steel requirements.

CONCLUSIONS l.

The Seabrook Green Concrete Blast Vibration Limit Program has provided valuable data which conclusively supported increasing previous blasting vibration limits. Based on the observations of the Seabrook work, there is strotig confidence to indicate that even higher vibration limits can be established if additional test work is performed.

2.

If no environmental, public structures, human tolerance or other safety considerations are involved, considerable margin still appears to exist in raising blasting vibration limits relative to the concurrent placement of concrete.

ACKNOWLEDGEMENTS The Seabrook Station Power Plant is jointly owned by a number of utilities. Public Service Company of New Hampshire is the major share-holder and agent for the owners. Yankee Atomic Electric Company is the Engineering Supervisor for the Owners.

United Engineers & Constructors Inc., is the Architect-Engineer and Construction Manager for the total facility.

Field wo,rk was carried on under the supervision and direction of United Engineers and Constructors Inc. Field Engineering Department by various'on-site contractors.

Stephen A. Alsup serve'd as bir.ec monitoring consultant and advisory to vibration testing phases.

(4)

APPENDIX - DIRECT REFERENCES 1.

"In-SITU Dynamic Elastic Moduli of Concrete During Curing Procesa for Maine Yankee Atomic Power Plant, Wiscassett, Maine", Weston Geophysical Research, Inc., Weston, Mass.

l 2.

" Measurements of Vibrations Caused by Construction Equipment and Blasting Report RR172", April 1971 Department of Highways, Ontario, Canada.

3.

Waddell, Joseph J. " Practical Quality Control for Concrete", McGraw-Hill Book Company, 1962, par. 7-8, Autogenous Healing.

4

" Measured Vibration Levels, Blast Shock Testing on Curing Concrete-Final Summary Report," S.A. Alsup & Associates, Inc., August 12, 1977 l

(Prepared for Public Service Company of New Hampshire.)

COMPENDIUM - Relative Documents on the Effects of Vibration on Green Concrete i

1110-2-3800 1

US Corps of Engineers, Engineering and Design Manual,EM dated March 1972, " Systematic Drilling and Blasting for Surface Ex-cavations", Chapter 7 - Damage Prediction and Control.

[

~12 I

Bastian, CE, "The Effect of Vibrations on Freshly Poured Concrete."

2.

Portland Cement Association, "The Effect of Jarring on Fresh 3.

Concrete."

Consolidation by Popovics, S, "A Review of the Concrete 4

Vibration," Materiaux Et Constructions, Vol. 6, No. 36,1973, Pgs. 453-463.

Voina, N.I and Mirsu, 0 "Some Aspects Concerning the Influence of 5.

Vibration (Revibration) and Retarders on Concrete Workability and Strength."

Wiss, John F, " Damage Effects of Pile Driving Vibration," paper 6.

presented at the 45th Annual Meeting of the Conunittee on Construction Practices-Structures.

Neville, AM " Properties of Concrete," Fresh Concrete-Revibration, 7.

212-213.

John Wiley & Sons, New York, pgs.

Larnach, W.J., " Changes In Bond Strength Caused By Revibration of 8.

Concrete and Vibration of Reinforcement," Magazine of Concrete Research, July 1952.

Bergstrom, " Test of Properties of Fresh Concrete," Magazine of Con-9.

l crete Research, October 1952.

10. Taylor, W.H., " concrete Technology in Practice" 2nd Edition Angus &

Robertson, London, England.

Post Program Documents

11. Krell, William C., "The Effect of Coal Mill Vibratien on Fresh Concrete", Concrete International, December 1979, as. 31-34.

i

12. MacInnis, Cameron, Kosteniuk, Paul W., " Effectiveness of Rivibration and High-Speed Slurry Mixing for Producing High-Strength Concrete,"

ACI Journal, December 1979, Technical Paper Title No. 76-51, pgs. 1255-1265.

13. Akins, Kenneth P. Jr., Dixon, Donald E., " Concrete Structures and Construction Vibrations," ACI SP 60-10, pgs. 213-247.

j

14. Chae, Yong S.,'" Design of Excavation Blasts to Prevent Damage,"

I Civil Engineering, April,1978, pgs. 77-79.

s i

i 13 lL---

9 4

l J J

• il 'I

.nu r.

...a c.'.10 au,,,, m,

=

..A i

-mb

• 4$

=

.co.

""a',',a

"'Ir l'"a

=

aa ax t

808 Loao ACfuavC.tC $'

p.

g n.o p-h.,3 wa 3

test

.se

,,o

.f

--i < nC u.i Co n

%j r

ac 2e

.e 15

• a 2.

=

F r

ic

-it 1 w, g ( 4,:

un a

fo-

'o~s '~

m-e _ a s,-

, 2.!* [

a,,

n.

0,,

ni O O., on

.t 1

i.

io

.3 00 in.m ne.

,. ~.

'* v A

3

2.,

0,.

in Om

.=,

Photograph 6 FIELD TEST WALL SHOWING

=

i.

O.,

3,. I u.

0,0 in 00n nii REBARS EXTENDED FOR 3

u.. u.

ns em on FULL-0UT TESTING avet.G. witeAft0 w.wt3 fo i.

13 CONWltSIODe f ACTOel - Cset edCM

• 25. astuangf fe5 CPet Tops. 07 3 saccaasal Oped PSe e.. astOPASCAtl A

'Q My

a w

t

. i.

• ?

ecsafGPT ' Elf Am{M LOADS

,,'f3 *

'Get 5MCWW W G.tfee CXst't age ce v0AaFON tfvtt ic'

-A.~,

~Q M

Ccsersat via Afe0

.. -. s.. -

W

~

CCac

? fit a,,,G, ay,,aa, e

eso Put our g

7

%^ C" W esO Put mf g

a,,,3,.,

=ecs auss nfy:N a 4 Q-mn e

ir.

e3 2

=

,,0

.m i n>

u.

7 2

r2. 750 1225 10

12. 1 5 i.30 Photograph 7 3

a e

isirs in it iun ine FIELD TEST WALL AFTER i

iui3 rw isn.

u.,

BEING BLASTED FROM FOUNDATION ium

,0,i is is i.0 in, CEPs[. tit CftsectB STEEas",fM5 Givlet eN fan $.

WD0 poscl e.53. anOGaa.as I,dhU us< niast v'esatieN emets pee tancear-re mf evt.een s ar cus tiep ya cos gratioN,,eenangue grancevegg

1. 1. fsMCT'WE OP e C&Cstif.GE of WWarcN tEvit Ovp CON _CRlff, AGE, a,y 3,,,

y,,,,

avtaact avttaG4 II STD Df u nreteeGfee litEt<GFM ni t far

.6 20

.0 0

sesCMS Pte RfC.

l 3

3343 53 9 32 32.S

11..

F 2.

3

.00, 7

3 2,.0

.. F 10 7..I 13 3 se EESPfCfivE PLACEntNT GOWf tNeNG ING.aQRt $f BtNGENT 3

2.

3 37 7

.l.

te 370 103 GaCLMO WliOOTT 99QuittentNTS.

3 2.S7 270

.I Nie sF OR 0 S seeCats Pt. 54CO*eo Af i.00 past on.000 peti peons 2.

3 35 3 it.

.3 31.

i$3.

feet Ana&f iDCATOas stSPECfivitt.

P 3

3e I3 1710 51.

ONG sesCM e 19.==

2.

3

• J.7

22..

21 3 09 11F W #007*OJOS=

OA8 Ples.

Est0Pa5Catl P00RDilBML

United States Department of the Interior 15

)

GEOLOGICAL SL*RVEY

=

RESTON, VA. 20092

..,- N. ab!!'j \\

ciTICE oF THE DDLECMR nff$"'

In Reply Refer To:

'n> -

July 25, 1980 EGS-Mail Stop 106 Dr. Robert E. Jackson Chief, Geosciences Branch Division of Engineering Mail Stop P-314 U.S. Nuclear Regulatory Commission Washington, D.C.

20555

Dear Bob:

Enclosed are comments in response to the August 9, 1979, letter from Mr. Frank Schraeder and to your letters of September 18, 1979, and October 18, 1979, requesting that the Survey review material relevant to determining the response of the Limerick Generating Station, Units 1 and 2, Docket Nos. 50-352/353, to nearby quarry blasting.

This review was performed by me, and we have no objections to your making this review part of the public record.

Sincerely yours,

_ -,; = - J

\\JamesF.Devine pcting Assistant Director for Engineering Geology Enclosure

. -y -

,, g n ~ -nyyg zy;

LT'

+

a__

w c..

DUPLICATE DOCUMENT

..i.

Entire document previously f

.fi entered into system under:

os ANO T8e EOl/ QC 7d_

.hd No. of pages:

l/

pyy:n.gn,

g csyy g; _~,.

z.-

n...ww

, - + _ m_

w unn

pt

/'k's United States Department of the Interior

_, ]3 GEOLOGICAL SLTT!

RESTON. VA. 2:2092

,s omCE oF THE DIREC"0R In Reply Refer To:

August 11, 1980 EGS-Mail Stop 106 Dr. Robert E. Jackson Chief, Geosciences Branch Division of Engineering Mail Stop P-314 U.S. Nuclear Regulatory Commission Washington, D.C.

205S5

Dear Bob:

In reviewing my letter of July 25, 1980, to you concerning the Limerick Generating Station, Units 1 and 2, Docket Nos. 50-352/353, I have dis-covered that an incorrect word was used in describing distances from the future blasting and Class 1 structures at the Limerick plant site.

ne word "manmum" in the second line of the fourth paragraph of the first page of review coments should have read " mini =um."

This now makes that sentence consistent with the first sentence of the first paragraph of page 2 of my coments.

I apologize for any inconvenience that this =ay have caused you.

Sincerely yours, n

k.=

ff James F. Deviae Acting Assisttnt Director for Engineering Geology coo)

S i/o 8008150

~

PHILADELPHIA ELECTRIC COMPANY rewano s. sausa. Ja.

2301 MARKET STREET v ie.....o

=,

um.. $caua n PHILADELPHIA. PA.19101 suc.c.Ns J. snacL.e.v

. xmv. m 6 cou...

CCNALD SLANMEN (2ISI S41-4000 9u COLPH A. CHILLEMt c.C."'"" ~^ "

July 29s 1980 T. M. WAMEM ComNELL Decket No. 50-352 and

• • u t. 4 u ca s*".".

6 eau."

.....v.,...

50-353 EC.W..A.R D..J,. CO LL.E.N J R.

.v cou Mr. l. S dwencer, Clief Licensir.g Branch No. 2 Civisicn of Licensing U.S. Nuclear ~@ter/ &=i ah Washington, D.C.

20555

Subject:

Li::exick Generating Sta* Blasting :'## acts Paferences:

1.

Letter, E. J. Bradle/ to R. L. Baer, dated Januar/ 15, 1980 2.

Iatter, E. J. Bradley to R. L. Baer, dated Februarf 14, 1980 3.

Letter, E. J. Bradley to Al Sc :wencer,. dated May 20, 1980 Cear hr. Schwerr.er:

A.-tached are #ive (5) ccpies of a rescrt titled "Cmparisen of Near-Site Cuarry Blast C.aracteristics to the Saieie-Cesicn at Limerick Generating Statien". S.is retx:rt was.pted at a :neetirs en rez 18, 1979, by representatives of the NBC.

?.e ccnclusien of the repcrt states that the respense spec ~m develcped frmt rec::rds of recer:t cuarry blasts are essentially envelcped at dtical frequencies Lf the CBE design spec ~m for dtical strrtures.

?.e subnittal of this report c:2rpletes all of the car.it:nents made by us at the Dececicer 13, 1979 meeting with NBC representatives.

Sincerely,

.n i

'V,

/

y

/ G.**. >,

r

\\

ICGDE J. SPACIH C

f h

300ao4o q

i l

l l

l COMPARISG CF NEAR-SITE CCARRY SIAST CEAFNCS l

T THE SEISMIC CESIG1 AT t

IIMERICK GDIFATDG S~4CN t

DCCCI NCS. 50-352 Ata 50-353 July, 1980 t

DUPLICATE DOCUMENT Entire document previously entered into system under:

%DO% Ot/0o07 aNo No. of pages:

x s

-