ML19332A117

Seismic Risk Analysis for GE Pu Facility Pleasanton,Ca, Part I

ML19332A117
Person / Time
Site:	07000754
Issue date:	07/31/1978
From:	TERA CORP.
To:
Shared Package
ML19332A116	List: ML19332A115 ML19332A117 ML19332A119
References
REF-PROJ-M-3 NUDOCS 8009100745
Download: ML19332A117 (57)

Text

_,

hs

/

i

.7!SMIC RISK ANALYSIS FOR GENERAL ELECTRIC PLUTONUM FACLITY P' FEANTON, CALIFORMA 1

PARTI i

samnea e LAWRENCE LIVERMORE LABORATORY

)

P.O. Box 808 1

Livermore, Califomic 94550 Attention: Mr. Don Bernreuter Project Me.cger 1

l t

g TERA CCRPCRATICN Teknekren Energy Rescurce Ardysts 2150 Shenuck Avenue Seekeley. Cct!forne 94704 415 845 5200 July 31,1978 80 0940'O lk8

3:

O i

ERRATA SHEET i:

Figure 5-1, Legend i.;

e J.

Calaveras is mis-spelled twice as "Calavaras".

[

Figures 5-3 and 5-4, ordinate scale should be labelled r

Kilometers i

p. 5-5, Table 5-2, j;

1-N for Northern Calaveras should be 0.012, not 0.009.

g n

p. 5-9, 4th paragraph, first two lines should read,

[.

t-.

Our estimate of the seismic risk represents the weighted results from five classes of calculations consisting of fourteen individual calculations. These calculations represent a base case and our j

perturbations about this base case.

i

p. 5-11, first line should read, Finally, we account for uncertainty in the background seismicity by considering it 70 percent probable.that the rate will be the rate derived from the data, and that it is again 15 percent probable i

that the rate will be four-thirds or two-thirds, respectively.

't 4

e I

I l

w.n

./

---,4

~.

s s

TABLE OF CONTENTS Section Pooe

1.0 INTRODUCTION

AND

SUMMARY

1-1 2.0 SEISMIC RISK METHODOLOGY..................................

2-1 Theory.......................................................

2-2 3.0 REGIONAL GEOLOGY....................................... -,.

3-1 Reg i ona l Owrvi ew.............................................

3-1 Sit e Geo logy..................................................

3-6 Geo logic Hazcrds..............................................

3-1I 4.0 SE ISM OLOGY.................................................

4-I 5.0 CALCULATIONS AND RESULTS.................................

5-1 input.........................................................

5-!

Attenuat i on...................................................

5-6 Results.......................................................

5-9 Response Spec trum.............................................

5-1I Conc l u si ons...................................................

5-12 6.0 BI BLI O GR APHY...............................................

6-I 3

b f

.-TdRA CORPCRATION 9

s

1.0 INTRODUCTION

Abe

SUMMARY

In this report, TERA Corporction presents the first of a two-part study oddressing the seismic risk of the special nuclear rnatoricts (SNM) facilltv of the General Electric Nuclear CenMr at Pleasanton, California. This report presents the results of a seismic risk onelysis that focuses on all possible sources of seismic octivity, with the exception of the postulated Verona Fault. The second report, currently under preparation, will oddress the risk from this porticular structure.

This project was directed by Don Bernreuter of the Nuclear Test Engineering Division at the Lawrence Livermore Laboratory. At ie.xA, the effort was aw.c+d by Lawrerce Wight.

This report is one part of a larger effort being directed by the U.4. Nuclect Regulatory Commission.

The NRC's objective in commissioning the overci!

report is to assess and improve, to the extent practicable, the dility of this facility to withstand odverse natural phenomenc without loss of capacity. This report focuses on earthquakes, the other natural hazards, being oddressed in

~

separate reports, are severe weather (strong winds and tornados) and floods. The

~

overall onelysis will provide an assessment of the consequences of an occident resulting from any of these naturel phenomenc. The assessment will expr.ss a quantitative probabilistic measure of the potential structurel dcirn,v. ana the release function. It will also provide a probabilistic estimate of the resulting dose of radioactivity to the public.

To ensure credible results, very sophisticated but well-occepted techniques were employed in this cc,6.r.w J of the project, on analysis of the seismic risk. The ecleulational method we used, which is based on Cornell's work (1968), has been previously applied to safety evaluations of major projects.

The historical seisrnic record was established after a review of evcilable litero-turc, consultation with operators of locci seismic arreys and examination of appropriate seismic data bases including the USGS, University of Californic end PE!S data bases.

I-l TiERA CORPCRATION

3 e

The resulting seismic record, covering the period 1769-1977, was used to identify all possible sources of seismicity that could effect the site. Inadequacies and incompleteness in this record were explicitly considered in this definition of source regions and their activity rates. Where there were uncertainties, we assigned subjective probabilities to the span of uncertainty.

The acceleration attenuation relation used in the analysis was developed based on a complete re-evaluation of all relevant strong motion data, with particular attention directed to the near-field environment.

To guarantee use of the best available calculational methods and input, the entire project was reviewed by two eminent seismologists with particular exper-tise in the local and regional seismology and tectonic setting:

Professor Thomas V. McEvilly, University of Califomic Professor Stewart W. Smith, University of Washington The results of our analysis, which include estimates of the uncertainty, are presented in Figure I-l. Our best estimate curve indicates that the Vallecitos facility will experience 30 percent g with a return period of roughly 130 years and 60 percent g with a return period of roughly 700 years. The curves on either side of our best estimate reptemnt roughly the one standard deviation confidence limits sout this best estimate.

These curves provide the seismic design basis for the Vallecitos facility in terms of peak ground acceleration. For those structures and equipment that could experience structural amplification, we rm.wis ad sealing the mean (50 percentile) alluvium response spectrum contained in WASH 1255 to the desired peak acceleration in Figure I-l. The uncertainty in these spectral accelerations can be derived using a tegnormal distribution of acceleration about the 50 percentile acceleration.

l-2 TERA CCRPORATICN y

+

w-

,w, y-

,w g-

1 10,000 l

i 1

4 6

f 4

(

l 6

i I

)

1 I

i i

l l

l l

/

l f

i.=0

,/

p l

. /

1

,s s.

s

~

s s

/

/

e 6s i

I

/ I I

ft l

l/

l/ l Y

l 5

l

/

/

/-

l I

/ /

00

. /

/

2y 1

1 1

i 1

1 4

/e

/

/

e t

i e

3

/t /

/ !

i e

i y

/Y

/

l t

l l

l c

/ /i /

I i

I i

//X l

l 10

'l

/

i i

f I

e t

i i

l i

i I

l l

l l

l 10 2D 30 4

50 60 70 80 PEAK ACm ORATION (% g)

FIGURE l-1 i

PEAK ACN RATION VS. RETURN PERIOD l

~

FOR THE VA1 ' CITOS SITE TERACORPORATICN

,y-

---. 7.-,.,

-w,-4,-.7--ww

2.o ses.c mse e<xxx_OGY A seismic risk anclysis is only as credible as the risk analysis methodology ed the input to it. This section presents the basis for our selection of a probcbilistic Poisson model for the risk assessment et the Vallecitos facility.

There are generally two distinctly different approaches to seismic risk molysis; probabilistic ed deterministic.

Using the deterministic approach, the eclyst judgmentally decides that an earthquake of a given mognitude or intensity occurs et a specific locatim. He then attenuctes the ground motion from the ecrthqucke source to the site ed determines the effects of that quake. The problem in using this cpprooch is that it is difficult to define the margin of safety or the degree of conservctism in the resulting design parameters. Analysts are often asked to provide informction on the "mcximum possible" or "most probable" earthquckes for design purposes, but the deterministic approoch does not ecsily provide those mswers.

The probabilistic apprccch, on the other hand, quantifies the uncertainty in the number, size, and location of possible future earthquakes and c!!cws an analyst to present the trade-off between more costly designs or retrofits and the economic or social impoet of c failure. Because the product of a probcoilistic cpprooch is a measure of the seismic risk expressed in terms of return period, this trade-off enn easily be quantified.

Although the probabilistic sproach requires significantly more effort than the deterministic approoch, it has the following odvantages:

~

e it qucntifies the risk in terms of return period e

it -!gorously incorporates the complete historical seismic record

\\

l 2-1 l

l j

l TERA CCRCCRAT CN t

it con incorporate the judgment and experience of the e

onelyst it accounts for incomplete knowledge regarding the loco-e tion of faults it has the flexibility to assess the risk at the site in terms e

of spectral accelerotion, velocity, displacement, or ecrth-quake intensity.

The credibility of the probabilistic approoch has been established through de-toiled technical review of its @ plication to several importent projects and crecs.

Recent coolications include m-wts of the seismic risk in Boston (Cornc!!,

1974), in the Son Francisco Bay Area (Vogliente,1973), in the Puget Sound Area (Stepp, 1974) and continental United Stc+es (Algermissen and Perkins,1976).

Results of these studies have been apolied to, among other crecs:

Development of long-range ecrthquake engineering re-e search goals Planning decisions for urban development e

Environmental hazards associated with the milling of e

uranium and Design considerations for radioactive waste repositories.

e This diversity of application demonstrates the inherent flexibility of the risk assessment opprooch.

THEORY The risk calculations con be fundamentclly represented by the total probability tim m..

P [A]

P [A/m and r] f (m) f (r) dmdr

=

g R

TERA CORPORATION

e

)

where P Indicctes probability, A is the event whose probcbility is sought, and M and R ore continuous, independent random variables which influence A.

The probability that A will occur con be ec!culcted by multiplying the conditionel probability of A, given events m and r, times the proboeilities of m and r, end.

Integrating over all possible values of m and r.

In our nuanment of the Vallecitos facility, A will be taken es mcximum acceleration and therefore P [ A/m and r3 will be derived from data relating peak occelerotion to epicentrol distence end earthqucke magnitude. Often known as ettenuation detc, these dcto cre usucily lognormally distributed cround a mean relationship of the form (McGuire,1977c).

A = C; e (R+ r,)

The distribution on ecrthquake mognitude, f (m), e n recdily be derived from en M

octuct or postulated frequency relationship of the form log N = o-bM where N is the number of ecrthquakes having magnitude grecter then M, and c and b cre constants chorocteristic of the particular source region under con-sideration. It follows (Cornell,1968) that f con be derived from the cumulative g

distribution function, F, which has the form, M

g = k (I-e' 3 M)

F where k is c normolizing constant and S : bin 10.

2-3 TERA CORPORAilON

The distribution on distance, f (r), depends on the geometry of the problem R

under consideration. For simple geornetries, the distributions can often be l

Integrated analytically. Realistic geometries however, require numerical eval-untion of the integral. A very versatile computer program has been developed (McGuire,1976b) that incorporates the theory presented above with a numerfect integration.d-.re that allows for evaluation of very complex source-site geometries.

Since the attenuation relation used in this analysis relates peak acceleration to distance from the nearest point of energy release, this program was modified to include a rupture rnedel. The model, which is epropriate only for line sources ed earthquakes that result in sipificant surface rupture (M = 5.5), assumes that an epicenter location is midway on the fault rupture length ed that the rupture length is related to :nognitude through the Mark and Bonilla relationship. Given a line so irce of seinielty and on epicentral location of an earthquake in that source, the model celculates the distance to the necrest point of energy release.

The overoll @proarh to performing seisrnic risk assessment by this theory is summarized below. Jirst, the historical earthquake record and local attenuation data are combined with the experience of the analyst to produce the functional relationships applicable to the area under consideration. The source regions are divided into circuloi sectors and proportional seismicity is o!!ocated to each l

sector. The total ex;.ected number of events causing maximum oecelerations at the site greater thm'a particular test acceleration is obtained by summing the events from eacP sector within each source region. The risk associated with this test acceleration is then calcuicted using ti,e conventioncl assumption that earthquakes have a Poisson distribution in time, it then follows hrt the return period is simply the reciprocal of the risk.

In recognition of the uncertainties in any sciserwabgical.snalysis, we test the sensitivity of results to variations, corresponding to the uncertainty, in key paramete<s. The results are then combined by assigning subjective probabilities to the rrnge of variations and weighting the results accordingly.

TERA CORPORATION

0

/

3.0 REGIONAL OLOGY The General Electric Compcny Vallecitos Nuclear Center is loccted in the Sen Francisco Bay Region which is bounded by mountain rcnges of the Coast Range Geomorphic Province. The crea is within the Diablo Ronce, approximately 30 miles southeast of the City of Ook!cnd.

The site slopes gently to the south. Deformed older sedimentary matericts consisting of cliuvici deposits of gravel, sand, silt, and clay undericy the study crec. These deposits include the Livermore grovels.

REClONAL OVERVIEW Recional Physiocrechv Regionctly, the study cree, Figure 3-1, is situated within the Diablo Range of the California Cocst Ranges. The crea constitutes the northern pcrt of the folded and faulted Mesozoic and Tertiary sedirnents of the Diablo Range. The crec hos several northwest trending ridges separated by volleys, largely bounded by faults.

The cree is now in an advanced stage in geomorphic development. However, this development is not uniform and is complicated by structural irregularities. The present landscge has clso inherited many erosionc! features developed during ecrlier cycles of erosion.

Headword grcwth of strearn volleys and conyon cutting cre now the dominent processes, forming steep and narrow gullies. Most of the ridges are between 1,500 cnd 3,000 feet high. The fict-topped crests of many of the ridges may represent remnants of a once extensive, gently undulating erosion surfcce. Most streams flow north or south, the notable exception being Alcmedo Creek, which flows west through Niles Canyon.

I 3-1 TdRA CORPCRATION

i F

gs at,.s'.ister,.~.. %g.rT,Tasos 8a.d.'.8".

• y

- m

-.ma

,r,

,,g

~,.... _,..

. - =......

gp.'.

-... g i r. p e % ~ : g :; y -

- l',~~-:

• W;,g.b6' WH 4.K ? e%'y *', f -'. i

~

w.:.,cw.+

.R...

~~~ Q Ra,s

 : p Ya.

, - 't,. ' 1.,,

• • /.:.

.s m.,,. 3.

~s. y.

1. 4;X.-;,.A yw._ %g. ~

.. 4 g.

.r.

', g. 3 5

j

-i g.

g N

.t

4. \\..

d,' e.

w,s.m

-;_,_ aj ! W %,%' m%y -. -a.- '

g:::-

...c.~.>,...

r.-

s e

.:......-_n. v

• r -

ih, w

s<:

.v srf 4

. :,.::,1@., u; fys

/

.f.,,

m

~ht.4, pM.n. '

. k -- < -

.N,7 ; -. :. c o

ss.

y

-- /... > w yM

,t."9 N,u:' w*4 '..!* M P' L Y. g..... p,c, fl.'.+,-9<nta -f; - Lt et

.t 1 r- -.

J.

d L %,,- --i,...

~

Sw' 'C

? ;e'..K(1.:,;'g--1.-l*'\\.pl:

s y-m $ p4 e,,,,

-i'*-((

C Qt"X$

O :"

. w- -

-r s n + :

1

'AN.M. _p.D. _.t.:n-'4:$$%~n~r5-- 2,%.d" i..._,,,a'S: '

' ~A

- N

% ~ ~a

m. a, i u ~L1.f..p.g,.. 3. ~ s :.-

mjm.,

>.... -;s,n_ n.t.

a y

.:N

%sAy.m-dp-Q.p;d@i4%F.N

. t,

..=. m,

. ir m._

.YE Q Q k.,%f.

' ~

'=R

,~%.

i P+.@ vie,. 5fy y..

ld W @ 4

' q. _

b._.,___. g '\\ - w h

_1

~

'" p @ m. m m a ' q T=- n

-i

.g

, i.-

- x'L 1

gwy

=-

.T, Irks W'W'M; 98 ^b..

._f -"..A,*, h*,,,3bgf1..

-.i

Jeg

..: la i.':=-,, -

. j:. k,

*b, nY.. '.'

4 %.

,..[aI'.*.l* *: 73.'".

' I'

.w s%,, ?..

%. Q '

W^ Q* M2)~...'.', n,,.. ~, f. %~:"~s. 's A:' '

t,

.. a

~.'% - Q.

A

-w~

-D x

2~

W.:.

4,. *

..c e- >.-

rp t

~~. -. - ~. -

.e.

\\

b = :.4; -e.;.,;'.

4,.. e.a.7.. g>. x_

.. a % -e -c *f. '

s+ <

y.y<.;

-g_

yF 3,

s..

q..

~~

J E![:A:"..g>.w- -

y-

k..

'--e y%.,r' W % ! D.,.: W. 1 a,

, '.., - e ( : :,,.,.

- g. %.

s

,) w., !

4

,q sq i h.,-

%. f,.

3

,p s,>

,.. W.

p g

%;Shh f%y

!nt t

' bNk$-~~wi; h.

Y g g n W+ 2 h m}L

+g W. n&mgwp;@@i GE-si:M$.:

4* W ~K 1.ma.n.= FW.W%

-piW wA Q~m h.NM~';.w;;~iL m

.A_ fhf,.

J Zi f " i_ c g' 6 e% c.., a 7

i SQ.}. 5~'f.I'.%

M %g-M.,

mc c. m i

, ).g"G f g.. =.

2';y D',.m.:l *.,; p1ts V-.i.,~.:b.[ivmi taa gry :ly:1<' 6,.*~._p--Q a.

x.

' ~ --

~ - wss. w.

< & mos.

c

/J Nl % %i f ;N d O Q.?kP 4 4.W T. Y &

2

W&4WS

\\

^

gw.m w.,ng.WNN.R

.-d?

Q 5n

-s. -

D.. mz em$hhWhh.~ ChW&:.

g.um

$Y]l hJ$W?"

m)'? N M E3 M.StiE M M NY.k M '

-, N s.= w -s m m m g,.. p z. g,v ggS-g. g v W

-r w jf!

35 W dQQi?QMCOQW& %. ~

.n:wL sp-ir.. cm._ -

'Gr.w a,..'g' ;_.,m., 4.- 5%F 2,,. -

n

.m--

w s

K.....vf,

%j-

$;[ %

..y~.1 a

- '* ; : y A ~.;\\

www.m_.f-[% )N, %

• • % j\\R G.

f. F Y,

:. ~.y.,'.. W m.

. a >. w ]} e _ Q;. w:.29 h. -

4Q.

s 45 gM

%gg y

\\

m.:':. _,s w

.m

.w.w--

."l* 1": ::::'*-* :"*.

.e

.-.-."me A

I-e l

,=':ll. ", '. " ".l, I

". * * ~

\\

"l".".".":"J"'"~~_~___.

1h *b

~

_ = = =.

g

_ _, =_-,,.a.a:

. " " " " ~ " " _ ". " *..

" '38."Wf="""

~ ~ ~['rwh..r.

FI N bl 2l.r

.W65 m

.e e e6 W TOPOGRAPHY OF THE m

SITE VICNITY ME IRACORPOR1TICN

C The geomorphic history is complex, each fault-bounded block a distinct unit with a history differing in part from that of the adjoining blocks.

Resistant formations form crests and odd ruggedness to the mountains. These features are subordinate to the larger forms such as ranges and volleys, upland surfaces, and basins. The prominent old land surfaces indicate that many of the mountcins in the western and southern parts of the cree have been elevated twice within relatively recent geologic time. The thick section of Livermore gravels suggests that the magnitude of these uplifts is Icrge.

Old lend surfaces may be recognized throughout the cree by the r.ectly accordent summits and nearly level ridge surfaces. The nome Oak Ridge surface wcs applied by Crittenden (1951) to the old Iond surface extending from Ook Ridge.in the San Jose quadrangle northward into the Pleasanton crec along Volpe Ridge and Moguire Peaks to Vallecitos Valley.

Across this surface much of the Livermore gravels were transported. Another surface, or a part of the Ook Ridge surface, is ecst and north of Mission Peck at the 1,200-foot level.

North of La Costa Valley on erosional surface is at the 750-foot level on the south side of the Verenc fault and at the 1,100- or 1,200-foot levei north of the fault. North of the town of Livermore worly oil the hills have been eroded to en approximate 680-foot elevation indicating still another old land surface.

The generei drainoge pattern of the cree is dendritic with larger streams parcilel to the main structural trends. Headword growth of stream volleys with little laterci cutting is now taking piece.

The mejor tcr~gi@ic features are as follows: (1) the strike ridges eclied Wei-pert, Sunol, and Pleasanton ridges undericin by Cretaceous rocks; (2) Divide Ridge (or "The Knife") consisting of Miocene rocks and separating port of Alameda County from Contro Costa County;(3) Mission Peak, which is seperated from the strike ridges by Niles Ccnyon; (4) Sunol and Amodor valleys, pcrolleling 3-2

(

r TcRA CORPCRAllCN i

l 1

the Calaveras-Sunol fault; (5) Livermore Velicy, a brood structural depression W.ich crosses the Mount Diablo Range diogonctly; (6) Moguire Peaks-Volpe Ridge-Woubs Ridge creo, the highest part of the region, with elevctions as high as 3,109 feet; and (7) the snell valleys of La Costo, Vallecitos, end a pcrt of the Artcyo del Valle (Holt,1958).

Recionel Geoloov During the Jurassic, this area was apparently part of a slowly sinking geosyncline in which several thousand feet of sandstone, shale and minor amounts of con-glomerate were occumulated. Following uplift and erosion, deposition of Creto-ceous sediments occurred. From the close of the Cretoceous to Late Eocene, land crecs rney heve persisted in the crec.

Warping, tilting and erosion must have occurred between the Olip w and Middle Miocene followed by deposition of the Pliocene Orinde Formction (Hell, 1958). After deposition of the Orinda Formction, the Middle and 1.cte Pliocene were marked by intense folding and faulting that destroyed the, Pliocene basins and resulted in tight or overturned folds. Faulting, erosion end elluviction con-tinue to the present and uplift in the Gucternary has caused several levels of terroces to form along some of the prominent streams (Hell,1958).

Recionel Straticrophy The sedimentary rocks in the crec range in age from Jurassic to Recent. The Cretaceous rocks consist of the Lower Cretaceous Ockland conglomerete con-formeely overicin by shale and siltstone beds of the Lower Cretaceous Niles Canym formation. The youngest Cretaceous rocks are the Del Veile formation of Late Cretoceous age (Holt,1958).

3-3 TiERACOliPCRATICN

The oldest Terticry rocks in this crec are the Eocene Tolman formation. The younger Terticry formations, which are rnore extensive, are the Sobrente sand-stone, Claremont shole, and Oursen sandstone of Middle Miocene age and the i

Tice shole and Hornbre sandstone of lower Upper Miocene oge. The Briones, Cierbo, and Neroly sandstones are upper Upper Miocene. The Orinde formation, Livermore grovels, and Irvington gravels are Pliocene and Pleistocene in age.

Recienc! Structure The most intensive faulting and fcVing occurred sometime between the Pliocene and Late Pleistocene. Recent movement clong the Haywcrd fault is shown by a variety of rift features. The mejor faults within the crec are the Cc!cvercs-Sunel and Haywcrd, both of which are right lateral faults.

The cree is here divided into three structural blocks that will be designcted the Scy, Sunol, and Livermore-La Coste. The Bay block is in the western part of the crec and is seperated from the Sunol block by the Hayward fcult. The Senol block is in the centrol pcrt of the crec and is sepercted from the Livermore-La Costo block to the ecst by the Calavercs-Sunol fault. Each of these blocks contains severcl folds and faults with a prevciling northwest trend. Most of the folds within this crec commonly make on angle of 15* to 20 with the trends of the faults, except in the Olvide Ridge cree where the angle between the axes of the folds and the Celeveros fault is 40. All the folds involve Tertiary as well cs older rocks.

Generally the folds are flexurel-slip structures with trends of cpproximetely 30*

to 50 west of north. The exici planes of the overturned folds dip to the northecst. Most of the folding took place offer the Pliocene Orinde formation was deposited and before the deposition of the Pli@teistocene Livermore gravels. The folds are commonly truncated by faults (Hell,1958).

The mejor faults in the creo commonly show post-Miocene strike-slip dispioca-ment of !crge mognitude. Possible pre-Miocene faulting was of the normal or high-ongle reverse type (Hell,1958).

l TdRA CCRPCRATICN l

c The strike-slip fcuits in the crea probably developed in response to north-south maximum compressive stress. These faults are commonly chcrocterized by on clignment of volleys and by transverse or tributory streams that cre cetively adopting to continued horizontal movement.

FMcing end faulting in the crea ronge f.om pre-Miocene. to Recent. The folding is co-Scered to be older than, or in pcrt contemporaneous with, the faulting.

The pctrem cf stresses has varied, as the strike of the beds roughly pcroliels the trend of the fcults, yet the latter are not thrusts, which would suggest con-temporencorn folcing and faulting. The principal time of regional deformation is believed to have been post-Orinda, possibly Early Pleistocene. Evidence that much of the fcultirx; occurred after folding is shown by the axes of folds that cre offset by the smclier crea faults.

Regionci Cround Weter The Vollecitos Nuclecr Centsr lies ! i the Vollecitos ground water subbasin, which is one of the three subdiv! sic.s of the Sunol Volicy ground water basin (De5~. i...ent of Water Resources, 1714). Both water-bearing and nonweter-bearing geologic formations occur witnin $e Sunol and Vallecitos Valley crecs.

In the Vallecitos Valley, water-beerbs ofiuvici deposits comprise the vclley floor, and the Livermore Formation, whid is exposed in the adjacent uplands, underlies the volley olluvium. Nonweter-cecring rocks occur on all sides of the volley and underlie the volley floor.

Unconsolidated deposits of upper Pleistocene to hemt :ge are grouped together os the Gucternary cliuvium which consists of strecm and loke deposited sediments including various mixtures of gravel, scnd, si!t cnd cicy (Derm. i. nEnt of Wcter Resources,1966). Available well log evidener, *be small size of the Vcliecitos ground water subbesin, and the known presence of me Livermore Formation underlying the volley all suggest that the olluvium bn not exceed 100 feet in thickness.

3-5 TERA CORPOPMON

o The Livermore Formation is of Pliocene-Pleistocene age md consists of massive beds of rounded gravel cemented by m iron-rich sandy cicy matrix. Sediments of this formation we divided into two facies; o clay focies found mly in Livermore Volley, and a more predomincrit gravel focies. The grovel facies are more typical of the Livermore Formation which is found at depths ranging from o few tens of feet to over 400 feet.

Nonwater-bearing rocks of Jurassic-Cretaceous age exist under Vallecitos Volley.

These rocks consist of hardened meine sandstone, shale and conglomerate, essociated with smaller omounts of greenstone, chert md serpentine. Where sufficiently fractured, jointed or bedded, these rocks may yield minor quantities of wcter that is of poor quality md probably unsuitcbie for most beneficici uses.

SITE GEOLOGY The General Electric Vallecitos Nuclect Center is located nect Plecsanton in Alcmeda County, Califomic. This site has e approximate cree of 1,534 ocres and is situcted on the north side of Vallecitos Vciley. The geographicci coordi-notes of the property we 37*37'N md 121 50' W with elevations in the building cree from 420 to 600 feet abow sea level. All the structures and facilities on the site are loccted in the southwest corner of the property.

Tooocrechv The Vallecitos Valley is a smcil westerly draining volley that lies m the westem slope of the Diablo Range et its northem end. The floor of the veliey is cpproxi-mately three to four miles in length ed a rnile wide. It is sepected from the larger Livermore Valley to the north by a range of hills with elevations of 1,000 to 1,300 feet. The site is leccted en the northern side of the valley near its westem end. The elevctions in the portion of the site occupied by the Center range from 420 to about 600 feet cbove see level. This imer site crea includes

~

3-6 TERA CORoCRATICN

the various buildings, laboratories, GETR, ed hos a general slope downward toward the southwest. Above the 600-foot contour line, the terrein chmges to steeper, rolling hills or,d canyons, which characterize the topography of the larger unoccupied north and northeast portions of the site.

Stretiercohv The Vallecitos Valley, in which the center is located, is blanketed by olluviel deposits of material washed down from the surrounding hills. This alluvium consists of sandy ed cicyey soils with varying amounts of gravel cnd rock frog-ments (Dames and Moore,1955). The low hills surrounding the volley consist of Livermore gravels, which genercily have a low dip to the ecst or north. The gravel formation is covered by recent olluvium of the Livermore Valley about four miles north of the site and overlaps Tertiary ed older rocks, which crop out about two miles south of the site. The totcl soil thickness at the site is probably several hundred feet.

The Livermore gravels consist of rounded closts of Franciscen debris in c brown or buff sandstone matrix. Sond, cicyey sand, and cicy are present and appear to be more abundant in the lower part of the formation. The gravels are f!ct lying or very low dipoing and rest with angule unconformity upon older rocks. A tuff bed near the base of the formation is estimeted to be of Plio-Pleistocene oge, approximately 4.5 million yects old.

Soils within the property boundaries of the General Electric Nuclect Center are representative of severci soil associations that occur en terraces, clluvici fms ed igimds throughout Sunol, Amador md Livermore Valleys (USDA SCS,1966).

Soils of the hilis to the north and rwil~,ut of the nuclee facilities are genercity of the Diablo soil series. These soils have considercble slope md are not suitcble for rnost methods of irrigation.

I TERA CORPCRATICN

Five soil series are represented within the selected cree of less than 30 percent slope with a combined cerecge of approximately 434 ccres. Generally, the soils are shcIlow or fine-grained, chwcn.ierized by slowly permeable subsoils, and cre subject to severe erosion if they are cultivcted and not protected. Major uses for these soils throughout Alameda County include posture, range, dry-formed groin and grain hoy.

Structure Tne Vcilecitos Nuclect Center is surrounded by three ecrthquake faults, Colo-veres, Verono and the Les Positos Fault (Herd,1977). The Calaveras Fault is a mejor structural feature of this port of Cclifornia (Depmiment of Water Resources, 1974). In the immedicte cree this fault extends clong the entire western side of Livermore Valley and southerly along the west side of the canyon formed by Arroyo de Ic Loguna to Sunol Valley. The existence, capcbility cnd location of the Verono and Los Positos Faults are currently quite controversici (General Electric Company,1977) but the seismic risk assessment described in the following sections explicitly addresses such uncertcinties. For this perticulcr situation, we account for the uncertainty by including a background seismicity representing ecrthquckes that con occur anywhere in the region on either undiscovered fcults or those faults whose capcbility is questioncble. We have not cddressed in our risk analysis the hazard associcted with surface rupture through the facility. Based on the results of detailed site investigations, the probcbility of this presently appecrs to be very remote.

Ground Water The Vallecitos Nuclear Center is located within. the Vallecitos subbasin of the Sunoi Volicy ground water bcsin. The five tr.cjor streams entering Livermore Valley are Arroyo los Posites, Arroyo Moeno, Arroyo Valle, Alcmo Creek cnd Tcssojero Creek (Department of Water Resources,1974). The Arroyo de la Logunc, the only surface strecm flowing from the Livermore bcsin, drcins the Livermore-Amador Volicy and empties into Alcmedo Creek. Alcmeda Creek flows westword through Niles Canyon and empties into Son Francisco Boy. The Vallecitos ground water subbesin is a relctively unimportent source of ground 3-8 TERACCRPCRATION _ _.

.n water being used primarily for stock watering and secondcrily for domestic supply for a few ranches.

Surface Water. Vollecitos Creek, which drains Vollecitos Valley, is on inter-mittent stream which rises in the eastern portion of the Vallecitos ground water subbasin and flows in a generclly northeast-southwest direction to enter Arroyo de la Logunc just above its confluence with Alcmedo Creek. The discharge from the Vallecitos Nuclear Center enters Vollecitos Creek about two miles above the confluence with Arroyo de la Lagunc. Vallecitos Creek flows primarily during the winter but due to ground water seepage there may be continuing ficw throughout the year (General Electric Company,1975).

1 l

Water from the South Boy Aqueduct of the State Water Project is provided to Zone 7 of the Alamedo Flood Control'and Water Conservation District and to the Alameda County Water District (ACWD) vic the surface strecms within the Livermore Vo!!ey. At those times when only the ACWD is taking water, a more direct route of water transportation is provided to the District through the utilization of Vcliecitos Creek. However, this ictter release is both intermittent and dependent upon varying conditions not readily predictable (General Electric Company,1975).

Ground water. Ground water in the Vollecitos subbasin is present under both confined and' unconfined conditions. Although the Livermore Formation is one of the principal water-bearing formations in the Livermore Valley, it assumes for less importance in Vollecitos Valley where the sediments are considered unproductive. As of 1950, only six wells were present in the subbcsin and these were oil low producing wells.

Four well logs are ovcilable from the Vallecitos subbasin (D% ine,t of Water Resources,1974). These logs indicate that ground water is contained in zones of sancy cicy and cemented grovels of the Livermore Formation. Depth to water at three of the wells ranged frorn 48 to 71 feet. Within the Nuclect Center, depth to water in the vicinity of Svilding 102 hcs been observed at 6 to 19 feet below 3-9 TERA CORPCRATION l

l l-

the surfoce, but borings 800 feet directly south of this location show no water.

At the site of the sewoge treatment picnt, seepoge was observed in on excavetion at a depth of cbout 10 to 15 feet below the surface (General Electric Company,1975).

The thinness of the olluvium contributes to its relative unimportance es e ground water source in the Vallecitos subbesin. Recharge to the subbesin occurs by infiltration of surfcce water draining from the rolling terrein clong Vollecitos Creek and its tributaries.

The combined potentiometric slope of the ground wcter roughly follows the ground surface es it slopes toward the center of Vcliecitos Volley (Department of Wcter Resources,1974). From this point, slope is westword toward the lower end of the subbcsin. The west side of the subbcsin is delineated by the Moguire Pecks Foult which seperates the Vallecitos and Sunoi subbcsins.

Due to the impermecoility of this fault zone, there is probably little outflow from the Vallecitos subbcsin into the Sunel subbcsin. It may be possible, however, that during its southwestern movement ground water mcy surface in the lower end of Vo!!ecitos Creek.

Similarly, subsurface inflow of ground water from other directions into the Vollecitos subbcsin also is considered to be negligible due to the nature of the subbcsin boundaries.

Recent dato on the chemical quclity of ground water in the Vallecitos subbosin were not available. Post data for four wells within the subbasin for the years 1957-59 were obtained and as shown by the detc, ground water quality at that tirne ranged from o ec!cium biccukste and mognesium bicarbonate to e sodium chloride wcter (Brown and Caldwell,1977). Generally, the results do not show cny significant changes in ground water quclity over the pcst 20 yects.

Perched ground water was encountered between depths of 24.5 and 25.5 feet. A deeper ground water tcble wcs encountered at a depth of 46 feet (po:,sibly a perched water table c!so). During a previous investigation, ground water was 3-10 TiERA CORPORAilCN

measured at depths of cbout 23 feet, ogcin, this probably corresponded to the perched ground water level. It should be noted that cil of the borings done for this study (Koldveer et cl.,1976) were backfilled within en hour offer drilling which rney not have allowed the ground water to reach an equilibrium level.

Also, it must be noted tnot fluctuations in the ground water level may occur due to verictions in the reinfall and other factors.

GEOLOGIC HAZARDS Although this report enphasizes the seismologic inswG ct the site, we also consider associated geologic hczords that could occur during on earthquake. The enclysis of these less direct but nevertheless significant hczards is bcsed on en extensive literature search, severci site visits and discussions with experts.

One of the most damaging phenomenc associated with ecrthquaker. is surface displacement. The displacement con be either faulted displacement or landslide displacement. This particulcr point cannot be conclusively defined at this time owing to the continuing investigetions et the site. It has been postulated (Herd, 1977) that the Verona Foult trace, discussed ecrlier, posses through the site within 1,000 feet of the SNM facility rcther than severcl thousand feet awcy cs had been previously believed (Hell,1958). The specific location of this fault remains very uncertain in spite of thrust-type displacements that have been observed in trenenes across the po,tulcted fault location. These particulcr offsets rney well be landslide induced (General Electric Company,1977), thus AT,csstrating the ecocbility of this crea for megolcndslide activity.

The subject of surfoce displacements and associated accelerations resulting from earthquakes on the postulated Verona Fault is treated seperctely in the second part report.

Other hczords associated with strong shaking include soil liquefcetion end flood-ing.

3-1I T_ EM CORPCRATICN

i Soil Liquefoetion Soll liquefaction is a phenornenon in which a saturated cohesionless soil layer located close to the ground surface loses strength during cyclic looding, such as imposed by earthquakes. During the loss of strength, the soil ocquires a mobility sufficient to permit both horizontal cnd vertical movements. Soils that are most susceptible to liquefoetion are clean, loose, saturated, uniformly graded, fine grained sands that lie within 50 feet of the ground surface.

Even under the conservative assumption that the soils are saturated to a depth of 20 feet, it presently appears that liquefaction does not represent a hazard for the site. This conclusion is based on grain-size analysis and standard penetration ?ut results for materials under the nearby General Electric Test Reacte.

/he underlying soils at the GETR site are predominantly clays and gravels with occasional pockets of sandy, silty cicy and sandy cicy. These sands, whose possible mobility could induce liquefaction, are of such density and grade that their mobility is very unlikely.

On the basis of the data available, it would appear that liquefaction is not c problem. ltaar, the uncertainty in the data and the possible intensity of excitation make this a most tentative conclusion.

Inundation Due to Dom or Embenkment Failure San Antonio Reservoir, about two miles south of the site and Del Valle Rewrvoir, about six miles east of the site are the only major bodies of water in the vicinity of the site (Kaldveer et al.,1970. Reference to the inundation maps prepared by the owning agencies (San Francisco Water 0% inst and the State of California Dw inst of Water Resources) indicate that the site would not be offected in the event of a dam failure at either of these reservoirs. Reasons include: existing drainoge ways, elevation differences and volume of water available.

3-12 IERA CORPORAT CN v.

~

Other water sources include rupture of the 500,000-gallon water storage tank on the site. In view of the fact that the Vallecitos site facilities are located on a brood, sloping hillside, tank failure would not result in appreciable flooding of facilities. A large portion of the water wcrald probably drain into Lake Lee. Any

~drainoge from the lake discharges into a large drainoge ditch, which leads to Vollecitos Creek, which is off-site.

1

)

1 3-13 IBA CORPCRATION

i 4.0 SE!SMOLOGY While the detailed elements of the seismic risk assessment are discussed in

}

Section 5.0, the historical seismic record is of such significance that it is dis-cussed separately below.

A complete evoluction of the historical record is the keystone to the risk assess-ment because of the important time and spatial distribution information it contains. With regard to time, the record provides detailed historical earthquake j

frequency information that con best be represented by the relationship, tog N =

o-bM. Further, the spatial distribution of earthquakes around the site con often be used to delineate seismic source regions within which earthquakes have l

commen characteristics.

I Local coverage of earthquakes was started in 1887 when the Berkeley, Mt.

Hamilton and Chabot stations were installed by the University of California. The quality and quantity of data avcilable was improved in the 1930's when Berkeley initiated a significant expansion of the network and subjected the data to routine seismologicel analysis. The pre-1930 record is a very valuable supplement to the more recent data but due to poor station coverage, much of these data cannot be reliably used in developing earthquake statistics for structures in the site creo.

Our general approoch is to use only the recently recorded data to determine the statistics for small earthquakes (ngitude 3.0-5.0) and to include the entire historical record in determination of statistics for larger earthquake magnitudes.

i We have collected and integrated the data from several seismic data bases to ensure the most complete coverage.

The primary source of data was the University of Californic (1975) seismic data base containing the eartnquake history of Northem Califomic through 1975. The data for the site area were checked and extended to 1977 by w. wing them with the unpublished records of the seismograph station. The expertise of Professor McEvilly was particularly l

valusie in establishing the representativeness of these data. Other data bases for seismicity that were excrnined for consistency checks included them of the California Division of Mines and Geology, the USGS Central Califomia Network and NOAA/NE!S.

4-1 I

' ERA CORPORATION 1

The resulting integrated earthquake magnitude date base for the relevant crec around Vollecitos 'is plotted in Figure 4-1.

Because of the large numbers of small magnitude earthquakes, Figure 4-1 shows only those of magnitude greater than 5; earthquakes as low as magnitude 3.0 were, however, included in the statistics ed molysis. Figure 4-2 presents the historical Modified Mercolli (MM) intensity record around the site; although this portion of the datc base is of less quantitative value, it supports the temporal distribution of the very Icrge earthquakes.

l There are several important features of the historical dato that must be included in any risk assessment.

The most important is the obvious clustering of seisrnicity in several localities.

l 1

i

)

The most obvious c xi well known source of seismicity in the site area is the San Andreas Fault. The 1906 eartnquake (M 8.3) on this fault, which resulted in o surface rupture from San Juan Bautista to Humboldt County, was one of the j

largest earthquakes ever to occur in this country. The southem sector of this felt also has experienced c major earthquake, the Fort Tejon ecrthquake of 1857. These two events have established the reputation of the Sm Andreas and associated faults, but the activity rate of the system is better determined by the

]

large number of lesser magnitude earthquakes.

Reicted to the San Andrecs system, but structurcily unique, are the Hayward and Calaveras fault systems.

These faits have also been the site of major earthquakes. In 1836 ed again in 1868, slippage on the Haywcrd Fault resulted in intensity Rossi Forel (RF) IX-X reports and in 1861 movement on the Calaveros Fault resulted in epicentral (RF) intensities of IX north of the site near Dublin.

Each of these major earthquakes result in strong shaking at the site, but impor-tent contributions to the historical site intensity record are also mode by the

~

smaller magnitude nearby events. In m effort to provide added credibility to our results, we have reconstructed the historical acceleration record at the site using both the historical intensity data ed the more recent mognitude date.

TERACORPCRATION r,.

_.y

,ymm, c

--+--w

---y

--wg--i,-

ra-

o e

o Magnitude 5.0 - 5.9 (1950-75)

O Mosnitude 6.0 - 6.9 (1906-75)

O Magnitude 7.0 - 7.9 (1906-75)

O==smi*"e 8 o - 8 9 (i9o'-75) oW 9.q\\

o m

\\'

i s

's

\\

o

\\

\\

\\

Smi:

g s

\\

o FIGURE 4-1 INSTRUMENTAL MAGNITUDES IN THE SITE VICINITY TERA CCRPCRATICN i

i

l s

/

O S0 MILES M

lli 3ik

\\

~~.,

's

'tX

~

's 1889 V1

/906 Vil IX ggf V?

g s,

/836

'g lil SITE

/858 VI.

Will gig Vill IX

\\

Vill FIGURE 4-2 HISTORICAL RECORD OF EPICENTRAL MODIFIED MERCALLI INTENSITIES IN THE SITE VICINITY

( 1813 - 1977 )

l TEiA CCRPORATICN

For example, using the Townley-Allen (1939) catalog as a dato base, we judge that during the period 1910-75 the site emerienced iI events of intensity (MM) V and seven of intensity (MM) VI. Site intensity (RF) V!9 reports have been reliably reported over a much longer time frame; we count six of these events between 1813-1975. Similarly, we believe the site has emerienced two (RF) intensity IX and one intensity (RF) X aver the some time. Table 4.1 provides a summary of the dates of these events. Richter (1958) has been M to convert RF intensity reports to the MM values indicated in this table. There is, of course, some uncertainty involved in inferring site intensities from isoseismal maps or surrounding intensity reports. These results, however, provide importent insight into the generci seismologic setting of the site.

It is evident that there are several historical earthquckes that have resulted in ir.edwistely high site intensities. Notable among these arc those earthquakes listed in Table 4.1.

These earthquakes are useful for estimating the seismic hczard at the site, but their location is also very important in determining the recurrence relation for specific structures. Because of this, the basis for the published locations of four significant earthquakes was carefully examined. Due to the obvious significance of the Calavercs Fault, particular attention was directed to relocating significant historical earthquakes that occurred in the vicinity of this structure. The relocation of the

• historical earthqxkes was accomplished through examination of old newspaper reports and synthesis of these data with those available from several historical catalogs, including McAdie (1907), Holden (1898) ed Townley and Allen (1939).

The overall conclusion was that in no case was there sufficient evidence for modifying the published locations of any of the earthquakes md in the case of one event the basis for the existing location was strengit r, d.

The earthquakes considered in the relocation molysis were those of 04 July 1861, 11 June 1903, 03 August 1903 and 01 Juiy 1911. All the cvoilable data from these earthqvckes were scrutinized and where specific historical 1:artions had to be determined, we consulted with the Special Map Collection of the Secroft Library, University of Califomic at Berkeley.

63 TERA CORPCRAilCN

i TABLE 4.1 StJMIAARY OF HISTORICAL SITE INTENSITIES Site Intensity (MM)

V VI Vil-Vill Vill-IX XI 8 i Nov 1914 1813*

04 July 1861 21 Oc* 1868 1933 26 Oct 1943

.7 1836*

18 April 1906 08 March 1937 09 March 1949 26 Nov 1858 15 April 1943 25 April 1954 26 April 1943 11 June 1903 16 Nov 1943 05 Sept 1955 03 Aug 1903 27 Aug 1945 24 Oct 1955 01 July 1911 22 June 1947 22 March 1957 17 March 1962 31 Oct 1958 10 Feb 1966 18 Dec 1967 9

• Precise dates unknown.

TERA CORPORATION l

l.

For the 1861 event, the key date for fixing the location ed epicentrol intensity were the reports that " men in the fields were thrown down" and "It opened c large fissure in the earth ed e new spring of water." From other accounts, we determined that the fissure was new a house belonging to Mr. Leobie ed the spring near Mr. Porter's. While we were unable to find Mr. Larabie's house, we were able to loccte Mr. Porter's house on a Sm Ramon Rancho Map prepcred in 1857.

The subject house was east of Danville's present location, nect the Blockhawk Ronch, thus strengthening the argument that the event wcs indeed located on the Colaveras and not a subsidley fault es the Los Posites, Pleasanton or Verenc.

In an effort to determine more precisely possible activity on the Les Posites Fault, we also relocated, using the Master Event Technique Evernden,1%9),

l four earthquakes of magnitude 4.0-4.2 that were pcrt of the 1943 swcrm in the Liver nore Valley. At that time, station coveroce wcs sufficiently socese to resul' in lege uncertainties of location. We have relocated these events relative to the locatien of the recent June 20,1977 mognitude 4.7 Livermera earthquake whose locction was determined much more precisely. The crciras showed thct the relocated epicenters were less the 4 km from the originct epicentecs and that the new locations did not generally elign with my known strue,tures including the Les Posites Fcult.

While the results of this relocation effort we by no means conclusive, they certcinly suggest that if the subsidiey faults cround the Cc8cvercs are active, their activity rates must be very low. It is on this k: tis that our onc!ysis high-lights the Son Andrecs, Mcywsd and Cclavercs Faults and does not explicitly consider other subsidiary faulting. Activity on these minor, but possibly necrby faults is however indirectly included in the enclysis; the following section pre-sents the details of these subjects.

i l

TiRA CORCCRAIlCN r

i 5.D CALCULATIONS AfC RESULTS in the previous sectims, we have discu sed the advantages of seismic risk analysis relative to deterministic approaches and presented a state-of-the-art calculational oproach to probabelistic seismic risk. We have also described the tectonic structure and seismicity of the area crow Vcilecitos. In this section, we gply these concepts ed date to a ssismic risk enalysis f r the Vallecitos site. The detailed input to the calculational model is described below, followed by a presentation of the results.

INPUT As described in Sect'en 2.0, Seismic Risk Methodology, the input to a probcbil-i istic seismic risk essessment comprises earthquake occurrence frequency relations, attenuation functions ed a specification of local source regions.

Because risk assessment eciculations are very sensitive to the particular com-position of the input, we consulted with several knowledgeoble seismologists during the preparction of input for the Vollecitos facility anclysis. Major sugges-tions in this regcrd were made by Professor T. V. McEvilly.

Source Recims

'After a thorough review of the historical seismicity, tectonic slip rates, micro-seismic dato and surface geology, we concluded that the gross source zones in the vicinity of the site defined by Algermissen ed Perkins (19%) were most appropriate for this molysis. Their definition of the source zones wcs bcsed on the rwdle assumption that future earthqucke occurrences will have the scme general statistics as historical earthquakes and that the historical vwiction of earthquake statistics from region to region con be used to de!!mit generci source regions. The final definition of the source region's boundaries was based e the overage separation distence for earthquckes producing the largest intensities.

)

The representation of the source regions synthesized all the avoilcble historicci seismicity dato ed the stete of knowledge of the reictionship between geologic structure end historical seismicity.

i TERA CORPORATICN j

i

Figure 5-1 shows the source regions that are appropriate for the analysis of the Vallecitos site. These regions encompass oil the significant sources of seisrnic activity within 200 km of the site. Their specification is generally consistent with the regionalization one would intuitively expect to be appropriate in that there is a San Andreas Zone, a Heyword-Calaveras Zone and a North County Zone.

In order to provide results that are more site-specific, we have subdivided the Hayward-Coleveras Zone into several subregions that model the specific faults in this zone. Thus, we model both the Ho>wd and the Coleveras Faults as line sources of width I-2 kilometers en either side of the surface trace. Although the activity in the eastern sector of the zone connot be associated with specific structures as it can in the western sector, the crea east of the Coloveros appears to be egable of significant activity and thus it is considered a separate and distinct crec source of gross activity. These zones are also shown in Figure 5-1.

Consistent with the b;storical record (Figure 4-1), these line sources and the eastern croc source are assumed to be the only locations in the zone that are capcble of earGquakes greater than magnitude 5.5; earthquakes of lesser magnitude are, however, included in the onclysis but they are not constrained tr.,

occur only upon these faults. Based on tne density of subsidiary faults within the zone, the entire zone was considered equcily capable of generating these smclier earthquakes.

Source Recion Seismicity Algermissen and Perkins (1976) calculcted the rates at which earthquokes occur in each of their source regions based on the seismic dato available et that time (1974). These rates, which are related to coefficients in the expression log N = c - b cre presented in Table 5.1.

5-2 i

TdRA CORPORAilON t

((((

Hayward Calavoros Zone North County Zone l

San Andrecs Zone

- Haywcrd & Colavoros Line Sources k

O SO MILES

= h

,g

\\

' s,\\

~

l 8

s s

- J

!s, ITE

/

y,

\\

ll,

\\

li i\\

Il j q FIGURE 5-1 SEISMIC SOURCE REGIONS USED IN THE ANALYSIS TSA CCRKRADON

TABLE 5.1 ALGERMISSEN AND PERKINS (1970 EARTHQUAKE FREQUENCY PARAMti ens Maximum Slope of the relation, Historicc!

Nurnber of MM Intensity logN:og Zone Earthquake (MM)

V's per 100 years b.

4 San Andrecs Xil i10 0.40 i

M County IX-X I4.9 0.50 Hayward-Calaveras X-X1 44.4 0.45 1

b l

=

h-5-3 N CORPCRATION w

w w

wv--c

--r-

-e-ww---rew

The percrneters o and b define the incremental distribution of ecrthqucke 7

epicentrol intensities up to on hypothesized maximum intensity. We convert these parameters to those @propriate for a cumulctive distribution on ecrth-quake magnitude by integrating the above relation over intensity ed converting Intensity to magnitude through Toppozcxic's (1975) statistically derived relation-ship M = !.85 + 0.49 I.

Toppoza:ic's relatimship is the most spropriate fx this eclysis since it was developed with o Northern Coiifornio-Nevado data base. We recognize the uncertainty in both the fit of a log N relctionship to the recurrence detc and in the coefficients within Toppozado's relationship; we account fx this uncertainty in the onelysis by sensitivity eclysis and a Bayesim combinction of results.

Deferring until later the quantificction of the uncertainties, the integration and conversion described cbcwe results in the ecrthqucke frequency parcmeters for I

each source region presented in Table 5.2. The overcil consistency of the results in Table 5.2 con be illustrated by comparing these results with other independent onelyses. For example, Bolt (University of Califemic,1975) hcs calculcted that the b-value for the Coast Rege Region, which includes all the source regions in this molysis, is 1.00 crid this is consistent with the overage b-value from Table Furthe, Evernden (1970) has determined that the b-value of the Sen 5.2.

Andrecs Fcult zone is approximately 0.86; we obtain 0.88. Finctly, Pfluke and Steppe (1973), using microseismic d::to, have calculated that for ecrthquckes es low cs magnitude 1.4 o b-value of 0.99 results for the Calaveras Foult.

We also present in Table 5.2 the earthqucke activity rates for the stbregions of the i-krfwmd-Colaveres zone. The slope of the frequency relation (b) is assumed to be the some for each subregion, but the total number of events in each stbregion is celeu!cted to be proportional to the totcl number of mognitude 3.0-4.0 earthquakes in each subregion cbring the period 1965-75. The logie for this cigorithm is that first, there are o sufficient number of these lower magnitude ecrthquakes to establish a rete for each stbregion md second, the U.C. seismic TERA COROCRATION

TABLE 5.2 EARTHOUAKE FREQUENCY PARAMticRS USED IN THE CALCULATIONS

'"~M l N = N*10' o

Maximum s o col Earthoucke Earthquake Zone N,

M, DM

%'Me (MM)

Scn Andreas 1.55 4.0 0.88 8.4 Xil North County 0.48 4.0 1.08 6.8 V!ll Hayward-Coloveres 1.30 4.0 0.95 See below tit wid-Colaveres 7

Subreciens tfwd 0.012 5.5 0.95 7.0 XI NeTrein Colaveres 0.009 5.5 0.95 6.8 Vill-IX Southem Celaveres 0.019-5.5 0.95 6.~8 Vill Eastem Arec 0.008 5.5 0.95 6.1 Vil-Vill i

Background

1.250 4.0 0.95 5.5 5-5 TERA CCRCCRAilCN

network become fully operational by 1965 thus providing coverage to this cree that was before uncycilcble.

Also shown in this table is our best estimate of the largest possible ecrthqucke in each region. Generally, this estimate is about 0.5 magnitude unit larger then the largest historical earthqucke.

To account for the uncertainties discussed above, we consider several other values for the maximum earthqucke. Table 5.3 presents the full range of magnitudes we consider in the eclev'ations.

ATTENUATION One of the keystones to my seismic molysis is the specification of decay of peck acceleration with distance from the ecrthqucke. Credible ettenuction relations have in the pcst been difficult to develop for two reasons: first the lcrge sectter in the dete makes a deterministic evoluction very difficult ed second, the date are very sparse in the near-field, thus allowing for a vcriety of interpretations.

i Because of its pcrticular significance et this site, e very cereful re-evoluction of all the mte was performed in order to ensure state-of-the-cri interpretation and mcximum credibility (Boore,1977).

The overall @proach to development of m ettenuation relation for this analysis is os follows:

1)

Use @propriate dato in the range 20-100 km to estimcte the for-field attenuation.

2)

Focus m the acceleration data et : 10 km to fix the trend in the necr-field.

3)

Rely on cil available data points at ranges less then 10 km to establish the very near-field occelerations.

Peck acceleretion date for development of the attenuotim relation were collected from the following sources:

TERA CORPCRATICN

TABLE 5.3 DISTRIBUTION OF MAXIMUM MAGNITUDE EARTHQUAKES USED IN THE ANALYSIS Lower Best Upper Zone / Subregion Bound Estimate Boted San Andreas 8.3 8.4 8.5 North County 6.3 6.8 7.3 l-ic7.,sd 6.5 7.0 7.5 1

t% net.

Calavoros 6.3 6.8 7.3

^

Southern Coloveras 6.0 6.8 7.3 Eastem Area 5.6 6.1 6.6 e

n C

s 9,

mm-cy 1

I e

Brune, et al.,1977 e

Galmopculos ed Drakopoulos,1974 e

Heks and Jchnson,1976 e

Boore, to be published,1977 e

USGS Clwicrs; 672,I972 717-D,I976 713, !974 736-A, l976 717-A,1975 736-8, 1976 717-B,1975 736-C,1977 717-C,1976 736-0, 1977 To introduce the cttenuation relationships used in this enclysis, consider Figure 5-2, which shows the data in the magnitude rege 6.0 to 7.0. The emphesis in this figure is on the 20-100 km ranges, but the evolieble very necr-field dato (less the 10 km) are c!so plotted. In this plot, rcrige is usucily the distance to the nearest point m the fcult er, the distence to the zone of principal energy release, if this em be determined. The dato are for both rock and soil sites since there appears to be no statistically valid reason fcr their discriminatim (Boore, 1977c). The relations are, therefore, for a typicc! site.

Superimposed on the dato are two citernative attenuation relations thct represent equally plausible near-field oemierations. We use both of these relationships in our analysis. The scatter abwt these mean relationships is best chcrocterized by c log normel one se-Ard devictim of 0.45. This fits the detc reasonably well ed is consistent with the dispersion calculated by other investigators (e.g., Donovan,1974).

These attenuctim relations, while based on the most current dato set available, do not represent a radical departure from previous recommendatims.

The acceleration w.,ed by these two relctionships, in fact, cover cil previously published attenuation relations.

This overell consistency serves to further validate our recommended relctions. The functionc! form of these relationships and their graphical representction is presented in Figures 5-3 ed 5-4.

TIERA CORPORATICN

2.0 -

O 1.0 -

0.8 -

0.L -

M-e O O O

0.2 -

"O o

o0 y

4 O

g O

3 0.i j m-O wOM-00 v

fa O

%O 2

0 A

M-0 0 4

t 0.08 -

0.006 -

0.006 -

m.

65M<7 e 02-21-73 Pt. Mogu

1. 0" Q.002 -

O 02-05 7 sem Femanco 0.001-i i

e i i iiiii i

4 6 i 6ieit i

1 1.0 2.0 4.0 ga 10 20 e

60 80 100 200 RMCE 0<m)

FIGURE 5-2 DATA BASE FOR THE MAGNITUDE 6.5 ATTENUATION RELATION TERACORPORAIION O

1

=

ATTDUATI0lt1

~*

A = 0.193 e (r + 12)-1.75 l

i i e 6

e.

, e i ese i..

1

}

l f

'l i l l I l al l

O O I l fs' i

i l i

'l i i l ill l

l i lIil l

I i

l l l llll l

l Ilill l

l l

)

1.o 7.5 k.

6.5,

,,i,,,

~

5.5 Ni ei A

e 6 i ilei i

i t I i i st 4.51 M I Mll iN i iiliitt I

t i i litil E

NXI NI

\\

l l I lilli l

I i i I l lli lI M\\\\

lllll l

! l lllll E

N 1\\

..i

)s x. x

,\\.

e i ie s ii

\\1 N ieNi.

e i

i....t I

i it ieIi t

\\\\ i\\t i IN i i t

i e ie i 1, i

l l I I i 111 l

. \\\\ K l i N I i

l i ! I11!I l

I l l lIll i

i MKl ill i

i i l I IIll 1 1

%NI\\

ll l

l M

\\

\\

\\

0.01

)

1.0 to.o 100 1c=

FIGURE S-3 ATTENUATION RELATIONSHIPS h4 TERACORPORAilCN O

~

-v

,,e

-,---,o

,e

---e--n.----e

,, ~,

ATTDUATION 2 A = 5.7 e (r + 10)~ *

'., i e i

4 i

,,....i 4

6 1

i l l ltl' t

Iii1 4

6 6 1 l tIl i

i l l l l 41 l

l 1

ilII I

I I I I I I' I

I i l l l l-l I1 ll l

1 i lill l

l l llll 7.5 I*"

4.5:

A Ai,..x 6.

i

,a.5,,

7,

,x,,in i

i

,,,,,,i

~

i

\\4 1 iN i1 \\

t t

i 4 $ 4 1ii t

i l i l iI.t 14.5 4 i

NIiIK

\\l I

I i l I ili I

i l i i t iIt I M l Nll\\ \\

l l l llIll l l l llll l !lTHshhh ll ll l

Il

NNN Ns\\

O.1 x

s s

s x

x w

w

.x x

n.

n..

.i....,

e x is, x iii..

..i,,: s e

i e i eiese i

N N

\\ s ti e s i

j

, I et tis I

i l I i i i11 1

IXiT lllli l

I i i i i iil l

I lil

\\kh 11\\

l i

i l I !!!!

l

\\\\ 'N I l llll

\\ \\

s s

N o.o1 1.0

.10.0 100 1003 FIGURE 5-4 ATTENUATION RELATIONSHIPS TBA CORPCRATION h

--,v.

RESULTS The results were obtained by computer calculations with a risk eclysis code (McGuire,1976b) that is based on the work of Cornell (1968). The bcsis for this approoch was summarized in Section 2.0.

As described in Section 2.0, the computer code calculates, for circular sectors within each source region at the site, the expected number of earthquakes per year cousing accelerations greater than a specified acceleration ed this is done for each source region. The expected nurnbers are summed for each region, and the resulting risk calculated from risk = 1.0 - exp(- expected mber per year).

The return period associated with the specified acceleration is the reciprocci of the expected number per year. It follows from the definition of return period that accelerations with a particular return period have a 63 percent probability of being exceeded within the return period.

Our estirnate of the seismic risk represents the weighted results from five indivi-dual calculations. The five calculations represent a bcse case and our perturbo-tions of input parameters sout this base. The perturbations are weighted by subjective estimates of their prob &llity of occurrence and thus their weighted combination results in a synthesized sensitivity study.

The parameters that are considered uncertain and which are included in this j

estimate of the risk are The maxirnum earthquake in each source zone e

e The extent of occeleration dispersion about the mecn attenutation relationships 5-9 TERA CORPCRAilCN

t e

The seismicity that connot be casociated with known faJits (background seismicity) e The cx:celeretion ettenuation relation.

The variations of these pcremeters represent the overcil uncertainties in our ability to define the strain energy limit of faults around the site, the correlation between scrthquake magnitude ed intensity, and the shcpe md level of the attenuation relation.

The base case for our results is considered to censist of the following input:

a Maximum earthquake = best estimate value from Tcble 5.3 Acceleration one standard devicticn dispersien, in cA = 0.45 e

Seekground seismicity derived from the data

,e Both attenuation relationships, equelly weighted.

We characterize ttw uncertainty in these dcte by considering that it is roughly 70 percent probcble itet the nmimum earthquake is as specified above md that it is 1.c percent probable that the maximum earthquake is roughly me-hcif rrognitude unit larger md co respedingly 15 percent probable that the maximum earthquake is roughly ene. half magnitude unit smaller. The values of these parameters are presented in Table 5.3.

Similarly, we consider that it is 70 ' percent probable that the acceleration disper-sien is as specified abwe ed thcrt it is respectively 15 percent probcble that the occeleration dispersion will be:

e in cA=

5 e

inog = 0.35 5-10 TIRA CCRPCRATICN

i l

Finally, we account for uncertainty in the background seismicity by considering it 70 percent probable that the rate will be the rate derived from the detc, ed that it is again 15 percent probcble that the rate will be cbuble or two-thirds, respectively.

We note again that the two attenuation relctionships are equally weighted.

The results from these fivt sets of pecmeters have been combined to produce our best estimate in occorhs with the probability of the combination. These results are presented in Figure 5-5. Also shown in this figure, and derived in the some way, is our estimate of the one stonderd devictions about our best estimate results.

RESPONSF. SPECTRUM The above results define the peck horizental occeleration at the facility for various return periods. We have also determined m appropricte response spec-trum for the site since some structures ed equipment have sufficier *!y low fundamentcl frequencies to experience spectre! cmplificction.

Our initici approcch to the definition of a response spectrum is empiricel; thct is, we base our recommendction on the shape of response spectro recorded in the near-field of strike-slip earthquckes. While wry sophisticated deterministic techniques exist which, through stress wave promation ecleulctions, em result in extremely site specific spectre, such cciculations first,.do not ecsily mesh with the probabilistic approach taken here cod second, are outside the scoce of this analysis.

The records chosen as most appropriate for definition of the spectro e e:

1)

The Cholome N 65* E component of the June 27,1966 magnitude 5.5 Parkfield earthquake.

2)

The El Centro S 00* E md S 90' W components of the May 18,1940 magnitude 6.3 Imperic! Valley Earthoucke.

5-11 TiERA CORPCRATION

.*o l

)

l 10,1Xio I

e l

l' l

l

/

l l

,/

IeM 1

s I

i i

f f

i i

t#

1. i e

I i

/

/

4 I

i

/I

/

fl l

l/

I/

/

E I

/

/

./$

5

/

/

/

e w

\\

~

s

.s Z

6

/i /

/

+

e e

i E

/ i/

/ 4 e

/ /

/

6 I

I i

E

/ /i /

I i

i I

//7 l

l I

to a 7

/

e a

6 i

r i

e i

e i

i I

i i

i i

l ll l

l l

l I

to a

m 40 50 m

a so PEAK ACN RATION (% g)

FIGURE 5-5 PEAK ACCELERATION VS. RETURN PERIOD FOR THE VALLECITOS SITE FenA CCRPORATICN

o The records were selected because they represent the frequency content in the near-field of a large strike-slip ecrthquake. h risk at the Vallecitos site is dominated by necr-field events--both intermediate and large events that occur on the Colaveras, and the smc!!er events that we represent in the background seismicity. The records selected are the only near-field records available and, fortuitously, they also span a reasonable magnitude onge. The Parkfield record represents a mognitude 5.5 event while the fo.deld records from the Imperial Valley Earthquake Indicated a 7.0 mognitude. The event was apparently episodic with the largest single subevent being magnitude 6.3 as determined in the nect-field.

When these response spectro are overicid, the resulting envelope spectrum is closely approximated by the 50 percentile olluvium spectrum contained in WA5H-1255 (USAEC,1973). Given the brooder basis for this latter spectrum and its overcil credibility, we recommend use of the 50 percentile WASH-1255 clluvium response spectre for structural onelysis. These spectro should be scaled by the desired peak occeleration from Figure 5-5.

CONCLUSIONS in summary, we have combined the best evcilable input dcto with the most credible tools of seismic risk onelysis to determine the return period of accelero-tion et the Vollecitos facility. The results, shown in Figure 5-5, account for the dispersion of the dato about the functional relationships used in the model. The results further account for variations in the upper mognitude e.;r-off. Other design response spectro een be determined by scaling the 1.0 g response spectrum in WASK-1255 to the desired peak acceleration.

5-12 l

N CORPCRATION I

1

s.

4.0 BIBLIOGRAPHY Aerial Photogrwhs, Pacific Aerici Surveys.

Alameda County investigation,1963. Department of Wate,r Resources, Bulletin No.13.

Algermissen, S.T.,1969. Seismic Risk Studies in the United States. 4tn World Conference on Earthquake Engineering, Vol. I, p.14.

Algermissen, S.T.,1974. Seismic Risk Studies in the United States. 5th World Conference on Earthquake Engineering.

Algermissen, S.T. and Perkins, D.M.,1976. A Probabilistic Estimate of Maximum i

Acceleration in Rock in the Contiguous United States: USGS Open File 1

Report 76-416.

Arer% P.M., 1943. Synoosis of the Later Mesozoic in Califomic. Calif.

State Div. Mines, Bull. I18, pp. I183-186.

Anderson, R., and Pock, R. W.,1915. Geology and Oil Resources of the West Border of the San Joaquin Valley North of Coolingc, Califomic. U.S. Geol.

Surv., Bull. 603, pp.186-187.

Arnold, Ralph,1908. The Miner Oil Field, Contra Costa County, Califomic. U.S.

Geol. Sury., Bull. 340, pp. 339-342.

Boore, D., 1977. Atterr. action of Peak Accelerations, Internal TERA report, August 13,1977.

Boore, D.,1977c. To be published.

Branner, J.C.,1912. Report on the Geology of the Livermore Valley. The Future Water Supply of Son Francisco, Report by the Spring Valley Water Co., pp.

203-222.

Brazee, R !., 1976. An Analysis of Earthquake Intensities with Respect to Attenuation, Magnitude and Rote of Recurrence. NOAA Tech. Mem. EDS NGSDC-2.

Briggs, ' '

1953. Upper Cretaceous Sandstones of the Diablo Range, Cali-fornia. Univ. Calif., Bull. Publ. Geol. Sci., Vol. 29, pp. 417-451.

Brown and Caldwell,1977.

Draft Lond Disposal of Wastewater Feasibility Study: General Electric Company Vollecitos Nuclear Facility, Vallecitos, Califomic.

j Brown, R.D. and Lee, W. H. K.,1971. Active Faults and Preliminary Ecrthquake Epicenters (1969-71) in the Southem Port of the San Francisco Bcy Region.

U.S.G.S. Map MF-307.

o'- 1 TiRA CORPCRAllCN y

y

++n7g--.

Brune, J.N., Prince, J., Hartzell, S., Mungic, L., and Reyes, A.,1977. " Acapulco Strong Motion Record of October 6,1974," Abstroet with Programs 9, Geol.

Soc. Am. 394.

Buwaldo, J.P.,1915. Occurrence of Oligocene in the Contro Costa Hills, Cali-fornia. Univ. Calif., Bull. Dept. Geol Sci., Vol. 9, pp. 9-21.

Buwaldo, J.P.,1918. The San Lorenzo Series of Middle Califomic. Univ. Calif.,

Bull. Dept. Geol, Vol i 1, p. 74.

Buwaldo, J.P.,1921. The Marine Tertiary of the West Coast of the United States. Jour. Geol, Vol. 29, No. 7, pp. 583-614.

Buwaldo, J.P.,1929. Late Movements on the : L ad Rift. Bull. Seismol. Soc.

7 Amer., Vol 19, pp.187-189.

Buwaldo, J.P.,1930. Tectonics of the Coast Ranges of Middle Californic. Geol.

Soc. Amer., Bull., Vol. 46, pp.1025-1078.

Clark, B.L., and Woodford, A. O.,1927. The Geology and Paleontology of the Type Section of the Meganos Formation, California. Univ. Calif., Bull.

Dept. Geol ScL, Vol 17, pp.63-142.

Clark, W.O.,1915. Ground Water Resources of the Niles Cone and Adjacent Areas, California. U.S. Geol Surv. Water Supply Peer 345H, pp.127-168.

Cook, Rufus F., 1949. The Upper Cretaceous Chico Formation at the Type j

Locality. Unpublished M.A. Thesis, Stanford University.

Cornell, C.A., ~1968. " Engineering Seismic Risk Analysis," BSSA 5,8(5) p.1583.

Cornell, C.A., and Merz, H.A.,1974. A Seismic Risk Analysis of Boston: Jour.

Structural Div., A.S.C.E., i 10, no. ST 10, Proc. Paper 21617, pp. 2027-2043.

Cornell, C.A. and Vanmerke,1976. The Major influences on Seismic Risk. 6th World Conference on Earthqueke Engineering.

Crandall, Roderic,1907. The Cretaceous Stratigrghy of the Santa Clara Valley.

Amer. Jour. Sci., 4th ser., Vol. 24, pp. 33-54.

Crittenden, M.D.,1951. Geology of t5e San Jose-Mount Hamilton Arec, Cali-fornia. Collf. State Div. of Mines. Bull.157, pp. I-74.

Domes and Moore,1955. Letter report: San Fraxisec, California.

Davis, F.F.,1952. Mines and Minero! Resources of Alcmeda County, Californic.

Calif. State Div. of Mines Report, Vol. 46, No. 2, pp. 279-348.

D% in nt of Water Resources,1974. (in Cooperation with Alameda County Flood Control and Water Conservation District, Zone 7,1974), Evoluction of Ground Water Resources: Livermore and Sunol Valleys, Bulletin No.

I18-2.

6-2 TERA CORDORAT10N y

-sw

---

y

-, - - ~ -. -,

• e Department of Water Resources,1966. Livermore and Sunol Valley's Evaluation of Ground Water Resources, Appendix A: Geology Bulletin, No. I18-2.

Diller, J.S., and Stanton, T. W.,1894. The Shasto-Chico Series. Geol. Soc.

Amer. Bull., Vol. 5, pp. 435-464.

Donovan, N.C.,1974. "A Statistlect Evolvation of Strong Motion Octo including the February 9,1971, San Femondo Earthquake," World Conf. Ecrthquake Eng., 5th, Rome 1973, Proc., Vol. I, pp. 1252-1261.

Earthquake Intensities,1972. Seisrnie Safety Information, Californic Division of Mines and Geology.

EDAC,1976. Evoluction of GETR for Operating Environmental and Postulated Accident Conditions. EDAC I17.08.

Erickson. M.R.,1945. Geology of the Western Portion of the Plecsenton Gued-rangle, Califomic. Unpublished M.A. Thesis, Univ. Cc!!f., Berkeley.

Esteve, L,1970. " Seismic Risk and Seismic Design Decisions," in Hensen, P J.,

ed., Seismic Design for Nuclear Power Plants; Comoridge, Messcchusetts Inst. Technology Press, pp. 142-182.

Esteve, L and Villaverde, R.,1974. Seismic Risk, Design Spectre, and Structurcl Reliability,5th World Conf. Earthq. Eng.

Evernden, JE.,1969. Precision of Epicenters Obtained by Smc!! Numbers of World Wide Stations, BSSA, Vol. 59, No. 3, pp.1365-1398.

Evernden, JJ.,1970. " Study of Regional Seismicity and Associated Problems,"

BSSA 60(2) p. 393.

Funkhouser, LW.,1948. Geology of the Arroyo Del Valle Arec, Alcmedc County, Collfornia. Unpublished M.A. Thesis, Stanford University.

Colonopoulus, A.C. and Drakopoulos, J. C.,1974.

"A T Phase Recorded on en Accelerc,vien," Bull. Seisrn. Soc. Am., Vol. 64, pp. 717-719.

General Electric Cowr.,ely,1975. Environmental Information Report, Vallecitos Nuclear Center, License Number: SNM-960, Docket Number: 70-754.

General Electric CmT4,ely,1977. Response to bRC Order to Show Cause, Octed 10/24/77.

Goldman, Harold B.,1969. Geology of San Francisco Bcy. Califomic Division of Mines and Geology, Special Report 97.

Greensfelder, R.W.,1974. Mcximum Credible Rock Acceleration from Earth-quakes in Califomic. C.D.M.C. Map Sheet 23.

6-3 TiRA CORoCRATICN

Gutenberg, B. and Richter, C5.,1956. Earthquake x mitude, Intensity, Energy, and Acceleration, BSSA Vol. 32, p.163.

Hall, C.A., Jr., 19'58.

Geology and Paleontology of the Pleasanton Arec, Alameda and Contro Costa Counties, California: Univ. Calif. Pubs. Geol.

Sci. Bull., Vol. 34, No. l.

Ham, C.X.,1952. Geology of the Las Trampos Ridge, Berkeley Hills, Californic.

Collf. State Div. Mines, Spec. Rept. 22.

Hanks, T. C. ed Johnson, D. A.,

1976.

"Geophysico! Assessment of Peak Acceleration," Bull Seism. Soc. Am., Vol. 66, pp. 959-968.

Harding, J.W., Jr.,1942. The Geology of the Southern Dort of the Pleasanton Guodrongle. Unpublished M.A. Thesis, Univ. Calif., Berkeley.

Herd, D.H., 1977. Geologic Map of the Las Posites, Greenville and Verona Faults, Eastern Alamedo County, Californic. U.S. Geological Survey, Open File Report 77-689.

Holden, E.S.,1898. Catalog of Earthquakes on the Pacific Coast, 1769-1897; The Smithsonian institute Collection No.1987.

Howell, B5., and Schultz, T.R.,1975. Attenuation of Modified Mercolli Intensity with Distance from the Epicenter: Seismol. Soc. Amer. Bult., Vol. 65, pp.

j 651-665.

l H.U.D. - U.5.G.5. 6csic Octo Contributions 7, 48, 59.

Huey, A.S.,1948. Geology of the Tesla Goodrengle, California. Calif. State Div.

of Mines. Bull I40,75 pp.

Jennings, Charles W.,1966. Preliminary Fault and Geologie Map. San Francisco Sheet. Cclifornia Division of Mines and Geology.

Jennings, Charles W.,1973. Preliminary Foult ed Geologie Mco. Californic Division of Mines and Geology, Preliminary Report 13.

Koldveer and Associates,1976. Geologie Mczords Study, Security Building, Gaeral Electric Vallecitos Nuclear Center, Pleasanton, Californic.

Kiremidilon, A.S. and Shah, H.,1975. Seisrnic Hazard Mapping of Californic, The John A. Blume Earthquake Engineering Center, Stanford University Report No. 21.

Kleinpell, R.M.,1938. Miocene Stratigraphy of California. Tulsa, Oklahome.

Amer. Assoc. Petrol. Geol.,450 pp.

Lawson, A.C.,1895. Geology of the San Freneiseo Peninsuic. U.S. Geol. Surv.,

15th Ann. Rept., p. 415.

TERA CORPORATION

o Lewson, A.C.,1914. U.S. Geol. Sury. Geologic Atlas. Son Francisco Folio No.

193.

Lawson, A.C., and Paloche, C.,1902. The Berkeley Hills, A Detail of Coast Range Geology. Univ. Collf., Bull. Dept. Geol. Sci., Vol 2, p. 371.

Loud sed, C.D.,1937. Characteristics of Active Faults in the Centrol Coast Rarges of Californic. Seismol. Soc. Amer. Bult., Vol. 27, pp.1-27.

Lui, S.C. and Fogel, L.W.,1972. Earthquake Environment for Physiect Design: A Statistical Analysis. The Bell System Technical Journci, Vol. Si, No. 9, p.

1957.

Lutz, G.C.,1951. The Sobrante Sandstone. Univ. Calif., Bull Dept. Geol. Sci.,

Vol 28, No.13, pp. 267-405.

Mark, R.K. and Bonilla, M.C.,1977. Regression Analysis of Earthquo<e Magni-tude and Surface Foult Length Using the 1970 Octe of Bonilla and Buchanan. U.S. Geological Survey, Open File Report 77-614.

McAdie, A.C.,1907. Cotoicg of Ecrthquakes on the Pacific Coast, 1897-1906.

The Smithsonian Institute Collection No.1721.

McGuire, R.K.,1974. " Seismic Structural Reponse Risk Analysis, incorporating Peak Response Regressions on Ecrthquake Magnitude and Distence," Mcsso-chusetts inst. Technology, Dept. Civil Eng., Resecrch Rept. R74-SI,371 pp.

McGuire, R.K.,1976c. "The Use of intensity Data in Seismic Hazcrd Analysis."

6th World Conference on Earthquake Engineering.

McGuire, R.K.,

1976b.

" FORTRAN Computer Program for Seismic Risk Anclysis." U.S.G.S. Open File Report 76 - 67.

McGuire, R.K.,1977c. "A Simple Model for Estimating Fourier Amplitude Spec-tro of Horizontal Ground Acceleration." Submitted to BSSA.

McGuire, R.K.,1977b. Effects of Lbeertainty in Seismicity on Estimetes of Seisrnie Hazard for the East Coast of the United States. BSSA Vol. 67 No.

3,p.827.

Newton, R.J.,1948. The Geology Northwest of Dublin, California. Lhpublished M.A. Thesis, Univ. of Calif., Berkeley.

Oliveira, C.,1974. " Seismic Risk Anolysis," Earthquake Engineering Research Center Report EERC 74-1.

Page, R.A., Boors, D. M., Joyner W. B., and Coulter, H. W.,1972. " Ground Motion Values for Use in the Seismic Design of the Trans-Alaskan Pipeline System" U.S. Geol. Survey Circular 672.

6-S TiRA CORCCRATION..

l e v.

Pfluke, J.H. and Stepp, J.A.,1973. " Magnitude-Frequency Statistics of Small Earthquakes from Son Francisco Boy to Parkfield" in Proceedings of the Conference on Tectonic Problems of the San Andrums System, Kovoch and Nur, Editors; Stanford Univ. Press.

Richter, CI.,1958. Elementary Seismology. W.H. Freeman and Co., Son Fran-cisco, California.

Robinson, G.D.,

1953.

Leona Rhyolite, Alcmeda Co., Californic.

Amer.

Mineralogist, Vol. 38, pp.1204-1217.

Robinson, G.D.,1956. Geology of the Haywerd Guadrangle, Californie.

U.S.

Geol. Sury., Geologic Goodrangle Series, Map GG 88.

Russell, R.J.,1926. Recent Horizontal Offsets Along the L #cid Fault. Jour.

7 Geot., Vol. 34, pp. 507-511.

Sc.1id41, P.S. and Seed, H.S.,1973. Accelerations in Rock for Earthquakes in the Western United States, BSSA,Vol. 63, p. 501.

Seed, H.S., and Idriss, l.M.,1970. A Simplified Procedure - Soil Liquefaction Potentic!. Earthquake Engineering Research Center Report No. 70 9.

Seismic Engineering Program Reports,1974. 'J.S. Geol. Survey Circular 713.

Seismic Engineering Program Reports,1973. U.S. Geol. Survey Circular 717-A.

Seismic Engineering Progrom Reports,1975. U.S. Geol. Survey Orcular 717-B.

Seismic Engineering Prograrn Reports,1976. U.S. Geol. Survey Circular 7 37-C.

Seismic Engineering Prograrn Reports,1976. U.S. Geol. Survey Circular 737-D.

Seismic Engineering Program Reports,1976. U.S. Geol. Survey Circular 736-A.

Seismic Engineering Program Reports,1976. U.S. Geol. Survey Circular 736-B.

[

Seismic Engineering Program Reports,1977. U.S. Geol. Survey Circuler 736-C.

Seismic Engineering Program Reports,1977. U.S. Geol. Survey Circular 736-D.

Smith, M.S.,

1934.

Ground Water in the Livermore Valloy, Californic.

Unpublished M.A. Thesis, Stanford University.

Special Studies Zone Maps, La Costa Valley Quadrangle.

Stepp, J.C.,1974. " Analysis of Completeness of the Earthquake Sompie in the Puget Sound Area and its Effect on Statistical Estimates of Earthquake Hazard." Proceeding of Conf. on Microzonetiem, Seattle.

TiRA CORPORATICN w-wr-

-T-

-ww-

=d

)

Taff, J.A.,1935. Geology of Mount Diablo and Vicinity. Geol. Sci. Amer., Bult.,

Vol. 46, pp.1079 1100.

Taff, J.A.,1940. The Type Locality of the Cretaceous Chico Formation. Geol.

Soc. Amer., Bull., Vol. 51, No. 9, pp.1311-1327.

Taliaferro, N.L.,1943. The Franciscon-Knoxville Problem. Amer. Assoc. Petrol.

Geol., Bull., Vol. 27, No. 2, pp.109-219.

Toppozada, T.R.,1975. Earthquake Magnitude as a Function of Intensity Date.

Bull. Seis. Soc. Amer., Vol. 65, No. 5, pp.1223-1238.

Townley, S.D. and Allen, M. W.,1939. De= riptive Catalog of Earthquakes of the Pacific Coast of the United States, 1769-1928. Bull. Seis. Soc. Amer., Vol.

29, No.1.

Trask, P.D., 1922. The Briones Formation of Middle Californic. Univ. Calif.

Bull. Pub. Geo!., Vol.13, pp.133-174.

Trifunoc, M.D.,1976. " Preliminary Analysis of the Peaks of Strong Earthquake Ground Motion-Dependence of Peaks on Earthquake Magnitude, Epicentro!

Distance and Recording Site Conditions," Bull. Seis. Soc. Amer. _66,(l) pp.

I89 220.

Turner, H.W.,1898. Rocks of the Coast Ranges of Californic. Jour. Geol., Vol.

6, pp. 493-499.

U. S. Atomic Energy Commission,1973. A Study of Verticci'and Horizonte!

Earthquake Spectra. WASH-1255.

USDA SCS (United States D% in-nt of Agriculture Soil Conservation Service),

1966. Soil Survey-Alamede Area, Californic.

United States Geological Survey,1966. Tectonic Creep in the Hayward Foult Zone. Circular 525.

United States Geological Survey,1975. Studies for Seismic Zonction of the Sen Francisco Bay Region. Professionc! Peer 941-A.

University of California, Berkeley Seiscr+Jie Station,1975. Catelogue of Eartnqvckes in Nwi;wn California and Adjoining Areas. Bolt and Miller, editors.

Vogliente, V.,1973.

Forecasting the Risk Inherent in Earthquake Resistent Design. Ph.D. Dissertation, Civil Eng. Dept. Stanford University.

Vickery, F.P.,1924. Structural Dynamics of the Livermore Region. Unpublished Ph.D. Thesis, Stanford University.

Weaver, C.E.,1909. Stratigraphy and Paleontology of the Son Pablo Fermetion in Middle California. Univ. Cailf. Bull. Dept. Geol. Sci., Vol. 5, pc. 243-269.

~

67 ISRA CORpCRATICN

.o u

o v

Weaver, C.E.,1944. Correlation of the Marine Cenozoic Forrnation of Western North America. Geol. Soc. Amer. Bull., Vol. 55, pp. 569-598.

Weaver, C.E.,1949. Geology of the Coast Ranges frWJately North of the Sen Freclsco Boy Region, California. Geol. Soc. Amer. Mem. 35,242 pp.

White, C.A.,1885. The Shasta Group. U.S. Geol. Sury., Bull.15, pp.18-32.

Williams, H., Turner, F.J., and Gilbert, C.

M.,

1954.

Petrogi phy.

San Frmcisco: W.H. Freeman ed Co.

Wilmarth, M.G.,1938. Lexicon of Geologic Names of the United States. U.S.

Geol. Surv., Bull. 896.

5 6

em D.

TERA CCRCCRATICN

__