ML20215K495

Responds to Questions Re SEP Topic III-6 Concerning Ultimate Bearing Capacity & Vapor Container Evaluation.Soil Beneath Vapor Container Footings Has Adequate Factors of Safety in Event of Bearing Capacity Failure

ML20215K495
Person / Time
Site:	Yankee Rowe
Issue date:	05/06/1987
From:	Papanic G YANKEE ATOMIC ELECTRIC CO.
To:	Mckenna E NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM), Office of Nuclear Reactor Regulation
References
TASK-03-06, TASK-RR FYR-87-49, NUDOCS 8705110226
Download: ML20215K495 (11)

Text

- _ _ _ _ _ _ _ _

TeUphons (617) 872-8100 TWX 710L380"7619 YANKEE ATOMIC ELECTRIC COMPANY

/

. h'k 0 1671 Worcester Road, Framingham, Massachusetts 01701

• YAN KEF~

v.

May 6, 1987 FYR 87-49 United States Nuclear Regulatory Commission Document Control Desk Washington, DC 20555 Attention:

Ms. Eileen M. McKenna, Project Manager Project Directorate - I-3 Division of Reactor Projects I/II

References:

(a) License No. DPR-3 (Docket No. 50-29)

(b) Letter from YAEC to USNRC (FYR 87-034), dated April 2, 1987 (c) Letter from Geotechnical Engineers to YAEC (Project 87085),

dated April 30, 1987

Subject:

SEP Topic III-6:

Ultimate Bearing Capacity and Vapor Container Evaluation

Dear Ms. McKenna:

The attached information is provided in response to questions by NRC staff. The questions concern the adequacy of the YNPS vapor container and the soil beneath the vapor container footings when subjected to seismic loads based on the NRC site specific spectra. This information supplements our previous submittal on this subject (Reference (b]).

Our evaluation concludes that the soil beneath the vapor container footings has adequate factors of safety with respect to bearing capacity failure for a deep footing analysis. The same conclusion was reached for an undrained strength analysis.

A summary of this additional evaluation under the vapor container footings is provided in Attachment A to this letter (Reference [c]). All of this inform-ation has been previously discussed by phone either with you or your technical reviewers.

Very truly yours, YANKEE ATOMIC ELECTRIC COMPANY G. Pap c, Jr.

Senior Project Engineer CP/gbc Licensing Attachment l

cc USNRC Region I gk USNRC Rocidont Inspector, YNPS I

0705110226 870506

\\

PDR ADOCK 05000029 P

PDR L

i GEOTECHNICAL ENGINEERS INC.

1021 MAIN STREET WINCHESTER MASSACHUSETTS 06890 (687)7214000

.mc=...

Ta'."C'=A".'1 *

• L"%'a;;%".:'

,,,,,/."O...

.,%o" '"5' Y'c April 30, 1987 Project 87085 Mr. Bruce Holmgren Mechanical Analysis Group Nuclear Services Division Yankee Atomic Electric Company 167 Worcester Road Framingham, MA- 01701

Subject:

Seismic Foundation Loads Vapor Containment Structure Yankee Rowe Nuclear Station

(

Dear Mr. Holmgren:

The purpose of this letter is to present additional information concerning the soil response to the subject loads.

This'information supplements our letter report of March 27, 1987 and presents alternative bearing capacity computations in response to questions raised by NRC staff during our meeting l

of March 24 and subsequent telephone conversations.

i 1.

Bearing Capacity Factors for Deep Foundations i

The foundations will have reduced contact areas when i

subjected to maximum seismic loads.

Thus the ratio of depth to effective foundation width will exceed one, and the foun-dation can then be considered deep.

The computations pre-sented in our letter report of March 27 were based on the following bearing capacity equation:

f Pult/ Area = qNg +0.5 TBNy e

where the terms are defined in GEI's March 27 letter report.

t orrlCES: CONCORD. NEW HAMPSHIRE oENVER COLORADO

Mr. Bruce Holmgren April 30, 1987

(

The same equation is considered to be applicable to deep foundations according to D'Appolonia (1975).

However, Bowles (1977) recommends for deep foundations a factor of 0.3 instead of 0.5 for the frictional (second) term of the bearing capa-city equation.

We have repeated the bearing capacity computa-tions for all the footings using the alternative equation with the 0.3 factor recommended by Bowles.

The results are pre-sented in Appendix D using the same format as in the March 27 letter report and utilizing the lowest drained shear strength friction angle of 35 degrees used in the letter report.

The factors of-safety against bearing capacity are higher than one for all the footings. The lowest factor of safety is 1.4 (footing F-15, Node 800) and all other footings have a factor of safety larger than 2.

Considering the very conservative assumptions made in the computations, the transient nature of the loading, and the inherent ductility of the dense glacial till, a factor of safety of one should be considered accep-table.

2.

Bearing Capacity Using Undrained Strength The factors of safety against bearing capacity were also determined using undrained, instead of drained, strength for the glacial till.

Three consolidated-undrained triaxial tests were performed by T. W. Lambe and Associ~ates in 1979 using block samples obtained from a test pit at Rowe.

All tests

(

showed a strong dilative behavior typical of dense soils with the stress path moving up along the effective strength enve-lope, which had a slope with a friction angle of about 37*.

The tests were stopped when the induced pore pressures became about equal to the initial consolidation value; however, the mobilized strength was apparently still increasing rapidly.

Experience with testing similar soils indicates that dilation and increased resistance would continue until cavitation of the pore water, i.e. at substantially higher mobilized strengths than reached in the tests.

4 The undrained strength mobilized at the end of the tests is plotted in Fig. 8 as a function of consolidation pressure.

The average consolidation pressure under and adjacent to the footings prior to the earthquake were computed to be equal to about 1,700 paf.

The corresponding mobilized undrained strength would be equal to 3,300 psf as per Fig. 8.

As state above, the available undrained strength would be substantially higher than 3,300 psf.

An estimate of the available undrained strength was made assuming that negative induced pore pressures would develop starting from an initial hydrostatic pore pressure of about 3 ft of water (corresponding to the shallowest footings) to a negative pore pressure (below atmospheric) of 33 ft, at which point cavitation could occur, Q

m x m m m o m m m m s m o.

i Mr. Bruce Holmgren April 30, 1987 thus the induced negative pore pressure would be 36 ft x 62.45 pcf = 2250 psf.

This negative pore pressure induces an additional undrained strength of 2250 x tan 37

- 1700 psf leading to an available undrained strength of 3300 + 1700 =

5000 psf.

The bearing capacity computations using an undrained strength of 5,000 psf are presented in Appendix E.

The was taken as a function of depth bearing capacity factor Nc ratio as per 3kempton (1951) for square footings, and further corrected to account for the rectangular shape of the contact area.

The appropriate reduction factor was applied to account for load inclination as per the USCE (1982).

The reduced con-tact area was also used in the computations.

The lowest com-puted factor of safety is 1.8, which as noted under Section 1 above should be considered acceptable.

It should be noted that the factors of safety for the undrained analysis are higher than for the drained analysis.

This result is reaso-nable considering the dilative character of the dense glacial till.

If you have any further questions, please call us.

Very truly yours, GE0' AL ENGINEERS INC.

(

Alfredo Urzus, Ph.D.

Project Manager myc d b E

Gonzalo G o, Ph.D., P.E.

Principal GC:ck Enclosures a

_,m., _,_,m.,,, _

REFERENCES

,t (1)

D'Appolonia, E.,

Ellison, R.

D.,

D'Appolonia, D. J.

(1975) " Drilled Piers," Foundation Engineering Handbook, F

H. F. Winterkorn and H. Y. Fang, ed. Van Nostrand Reinhold, New York, pp. 121-147.

[2]

Bowles, J. E. (1977) Foundation Analysis and Design, Second Edition, McGraw-Hill Book Company.

[3]

Skempton, A. W.,

1951. "The Bearing Capacity of Clays,"

Building Research Congress, London.

The Institute of Civil Engineers, Division I., p.180.

[4]

Mosher, R. L. and Pace, M. E. (1982) " User's Guide:

Computer Program for Bearing Capacity Analyses of Shallow Foundations (CBEAR),"

Instruction Report K-82-7, U.S. Army Engineers Waterways Experiment Station, Vicksburg, Mississippi.

(

t

(;)

S D

T E

S T

E E

N A

T D

B E G I

~

M HEN L L A

W HS O

I I

A S

X L

TTA N

A E

.W AD O

I HER C

C R

T T

TPN

)

Y9 PI EO B79 TTL L

ASI S0 C T

.C T

IES SS D

Ns R

EE NES Sn I

TT WA T' r A

S E

W Eu I

MC WS OO OTH N c>

I RS RST G s.

FS REG Ns A

ATN E.

S A

E Lu E

TD EER A.

Ca AN HHT I

r T

DA TTS Nvs t

O C<

i O.o E

N 2

l T

00 Ew I

0 G

5 0

1 0

/

l 0

4 n

/

)

I S

8

/

0 p

0

(

G 0

I 3

c F

/

/

/

0 t'

0 0

2 l I i l l I I l I I 0

g 0

0 1

0 3_

0 3_

o

~

gO o8*

8S s

e

_:O IFEEg

<=I" o

_<oOZ3 p\\

8

-I e

I 6

Sheet 1 or 3 Ta8LE D.

OBalNED BESSING CaractTT ANALYSIS,$335' WAPOR CONTAIMER - TANKEE ROWE Maanir-Scation Ma s.

l Footinat Mode TifET A THETA Mu Mw Ee/L Ew/L Factor Press.

De st Bad in-k sn-k ksr F-9 790 180.O

. 3.14 5114 3427 0.26 c.17

4. 8 6.92 F-8 791 202.5 3 53 5545 2288 0.31 0.13

5. 2 6.79 F-7 792 225.0 3.93 5756 245 0.33 0.01

4. 0 4.97 F-6 793 247.5 4.32 5298 2428 0.29 0.13

4. 7 6.10 T-5 794 270.0 4.71 4293 4022 0.20 0.19

4. 0 6.24 F-4 795 292.5 5.11 2981 6016 0,11 0.23

3. 6 6.87 F-3 796 315.0 5.50 173 7715 0.01 0.27

3. 0 6.16 T-2 797 337.5 5.89 2929 6818 c.11

c. 26

3. 9 7.41 F-1 798 360.0 6.28 6184 5434 0.28 0.25

7. 0 10.94 F-16 799 22.5 0.39 7025 2801

c. 39 0 16 10.0 12.89 F-15 800 45.0 0.79 7621 112 0.45 0.01 13.0 15.78 F-14 801 67.5 1.18 7360 2646 0.35 0.13

6. 6 9.99 F-13 802 90.0 1.57 6978 5827 0.27 0 23 6.0 11.11 F-12 803 112.5 1.96 3448 8124 0.13 0.30

m. 9 9.47 F-11 804 135.0 2.36 66 7682 0.00 0.25

2. 7 5.80 F-10 805 157.5 2 75 2905 5465 0.13 0.24

3. 8 6.35 l

1 I

I i

i Ceoteemascal Entineers Inc.

Protect 87085 april 29. 1987 i

i l

i I

I I

E

7 A

l i

Sheet 2 or 3 Ta8LE D.

( CON 7. 3.

DDAINED BEADING CAPACITT ANALYSIS TAFOR CON 7&lNER - TANREE ROSE Minimum Movimum Shape Fact. Inclination Feetors Over-Footing Mode 8*

L' Di me ns i on Di me ns i on Fes=Tes Foi FRi Depth Burden rt rt ft It ft kst l

(

F-9 790 5.14 6 91 5.14 6.91 1.27 0.54 0.10 7.92 0 745 F-8 791 4.08 7.85 4.08 7.85 1.19 0.53 0.09 7.50 0 718 F-7 792

3. 5'O 10.20 3.50 10.20 1.13 0.60 0.17 8.92 0 807 F-6 793 4.33 7.68 4.33 7.68 1.21 0.53 0.10 8.08 0.755 F-5 794 6.34 6.60 6.34 6.60 1.35 0 53 0.09 8.33 0 770 F-4 795 8.14 5.75 5.74 8.14 1.26 0.52 0.08 8.58 0.786 F-3 796 10.37 4.82 4.82 10.37 1.17 0.48 0.05 9.00 0.812 F-2 797 8.17 5.08 5.08 8.17 1.23 0.49 0.05 9.00 0.812 F-1 798 4.52 5.24 4.52 5.24 1.32 0.52 0.08 10.25 0 810 F-16 799 2.26 7.21 2.26 7.21 1.12 0.54 0.10 10.25 0.810 F-15 800 1.01 10.36 1.01 10.36 1.04 0.56 0.13 10.25 0.890 r-14 801 3.07 7.83 3 07 7.83

1. i t 0.63 0.22 12.25 1.015 i

F-13 802 4.80 5.74 4.80 5.74 1.31 0.66 0.27 14.25 1.140 F-12 803 7.80 t 14 4.14 7.80 1.20 0 51 0 07 10.00 0.874 F-11 804 10 45 5.20 5.20 10.45 1.18 0.42 0.01 6.00 0.625 F-10 80%

7.87 5.56 5.56 7.87 1.26 0.43 0.01 6.00 0.625 l

Profeet 87085 Centechnical Engineers Inc.

April 29, 1967 j

l

)

l j

an.

v~a w yc-WPy%MW'W w.--

- q 4%..,...a = +.+

5

. w n oe n -

N, 4

Sheet ) of 3 TABLE D.

ICONT.I.

DRAINED BEADING CAPACITY ANALYSIS TAFOR CON 7AINER - TANIEE Rout F

P FootInt Node cult 1 eult2 eult-tot A*

uit.

vert.

F. S.

ksF kst ksf so it kips kips F-9 790 0.624 17.124 17.748 35.5 630.1 159,0

4. 0 F-8 791 0.402 15.0R8 15.490 32.0 495.8 143.9

3. 4 F-7 792 0.632 18.104 18.736 35.7 668.6 137.0

4. 9 F-6 793 0.460 16.230 16.690 33.2 554.3 171.0 3.2 F-5 794 0.733 18.480 19.213 41.8 803.7 171.9

4. 7 F-4 795 0.565 17.299 17.865 46.7 R 34. 3 210.5

4. 0 F-3 796 0.247 15.330 15.576 50.0 778.5 226.3

3. 4 0.285 16.175 16.460 41.5 683.1 209.6

3. 3 F-2 797 F-1 798 0.447 20.365 20.813 23.7 493.1 172.3

2. 9 F-16 799 0.293 17.948 18.191 16.3 296.7 142.1 2.1 F-15 800 0.122 17.256 17.378 10.4 181.3 133.8

1. 4 F-14 801 0.718 24.397 25.115 24.1 604.7 164.8

3. 7 F-13 802 1.549 32.762 34.311 27.6 946.9 209.2

4. 6 F-12 803 0.335 17.871 18.206 32.3 588.6 213.0

2. 8 F-11 804 0.055 10.384 10.439 54.3 567.1 241.4

2. 3 F-10 805 0.082 11.246 11.328 43.8 495.7 184.3

2. 7 Geotechnical Entineers Inc.

Froject R7085 April 29, 1987

m 1

Sheet 1 oF 2 74BLE E.

UNDRAINED BEARING CAPACITY ANALYSIS VAPOR CON 7AINER - TANKEE ROUE P

Static Depth.

Over-Ne rect./

Nc Footang Mode (statici Stress D

burden B'

L*

Ne square D/ B' Fci square kips ksF ft ksF ft ft F-9 790 271.6

2. 5 7.92 0.745 5,14 6.91 0.96 1.54 0.54 8.1 F-8 791 265.7

2. 4 7.50 0.718 4.08 7.85 0,92 1.84 0 53

8. 3 F-7 792 271.3

2. 5 8.92 0.807 3.50 10.20 0.89 2.55 0.60

8. 7 F-6 793 264.4

2. 4 8.08 0.755 4.33 7.68 0.93 1.87 0.53

8. 3 F-5 794 265.1

2. 4 8.33 0.770 6.34 6.60 0.99 1.31 0.53

7. 9 F-4 795 267.2

2. 4 8.58 0.786 5.74 8.14 0.95 1.49 0.52 80 F-3 796 271.1

2. 5 9.00 0.812 4.82 10.37 0.91 1.87 0.48

8. 3 F-2 797 273.6

2. 5 9.00 0.812 5.08 8.17 0.94 1.77 0.49 8 2 F-1 798 287.9

2. 6 10.25 0.890 4.52 5.24 0.98 2.27 0.52

8. 5 F-16 799 291.4

2. 6 10.25 0.890 2.26 7.21 0.09 4.54 0.54 90 F-15 800 294.9

2. 7 10.25 0.890 1.01 10.36 0.86 10.15 0.56

9. 0 F-14 801 314.5

2. 9 12.25 1.015 3.07 7.83 0.90 3.99 0.63

9. 0 F-13 802 327.8

3. 0 14.25 1.140 4.80 5.74 0.97 2.97 0.66

8. 8 F-12 803 296.8

2. 7 10.00 0 874

4. 14 7.80 0.92 2.42 0.51

8. 6 F-11 804 260.7

2. 4 6.00 0.625 5.20 10.45 0.92 1.15 0.42

7. 7 F-10 805 257.6

2. 3 6.00 0.625 5.56 7.87 0.95 1.08 0.43

7. 7 Geotechnical Engineers Inc.

Protect 87085 April 30, 1987 e

O P

m s

a

. a

l 7

i

',C O'

,.. 1,

' 1 Sheet 2'of 2 1

7ABLE E.

(CON 7.3.

UNDRetNED 8EARINO CAPACITY ANALYSIS 8

. VAPOR CONTAINER YANEEE R0WE 1

~

Nc Foot 6nt Mode

rect, e uit.

A' P uit.

P vert.

F. S.

ksf.

sg:ft kips

-kips j

F-9 790 7.77 21.72 35.5 771.4 159.0

4. 9 F-8 791 7.66 21.02 32.0 673 3 143.9

4. 7 F-7 792 7.79 24.16 35.7 862.7 137.0

6. 3

)

F-6 793 7.72 21.21 33.3 705.5 171.0 4.1 j

F-5 794 7.85 21.57 41.8 902.7 171.9

5. 3 i

F-4 795 7.62 20.60 46.7 962.7 210 5

4. 6 F-3 796 7.59 19.03 50.0 951.0 226,3

4. 2 F-2 797 7.70 19.69 41.5 817.1 209.6

3. 9 F-1 79S 8.31 22.50 23.7 533.0 172.3 3.1 F-16 799 8.01 22.52 16.3 367,0 142.1

2. 6 T-15 800 7.70 22 45 10.5 234.9 133.8

1. 8 i

F-14 801 8.12 26.61 24.0 639.6

.164.8 3, 9 F-13 802 8.57 29.42 27.6 810.6 204.2

4. 0 F-12 803 7.95 21.16 32.3

.683.2 213.0

3. 2 F-11 804 7.08 15.50 54.3 842.0 241.4

3. 5

)

F-10 805 7.34 16.40 43.8 717.7 184.3

3. 9 f.

I f

I Caotechnical Engineers Inc.

Pro.tect 87085 April 30. 1987

k. ~

4

- =

A -

N

...m.

4==

n.

.w

.