Frank W. AtehLey - SLAC · Tunnel cobl;apse or fdlure due to forces of gravity causing swelling or...

SITE FEASIBILITY OF STAI”0RD’S PROPOSED 2-MIIX LMEAR

EI;ECTRON A C C E W O R

BY

Frank W. AtehLey

R o b e r t 0. D o b b s

Stanford University JufY 1959

Rrofessor E. Le Ginzton, Director Micrawme Laboratory Stanford University Stanford, California

Dew Dr . Ginzton:

Presented herewith i s our report on the s i t e feasfbi l i ty df the proposed l ineas accelerator based on information acquired t o date, including documentation where possible.

It is our considered opinton tha t wlth respect t o geogrqhic loea- tion, topography, relative construction costs, and natural. hazards, the proposed s i t e is a feasible location fo r the planned accelerator.

Very t ru ly youps,

Ifrank W, Atchley

RESEARCH ASSOCIATES (Geologists)

ii

CONTENTS

Page 1 INTRODUCTION

SUMMARY AND CONCLUSIONS

SITE REQvrri'EMENTS

SITE FEASIBILITY FACTORE

Construction Costs

Tunnel Hazards

NATufiE OF EARTHQUAKk3

Types of Earthquake Damage

EARTHQUAKES I N THE SAN FRANCISCO BAY =ION

EFFECTS OF EARTR&UAI(ES ON TUNNELS

TUNNELS I N CALIFORNIA

GENERAL GEOLOGY

Regional Geology

LocaS. Geology

APPRAISAL OF PROJECT HAZARDS

APPENDICES

A,

B.

C,

D.

E.

F.

MEep of Earthquake Epicenters in San Francisco Area

Effects of Earthquakes on Tunnels, by C. Me Duke and D, J. Lee&

L i s t of California Water Tunnels

Engineering Geology of the Proposed Site of Project "M", Stanford, C a l i f . , by H, C. Langerfeldt and L, W, Vigrass

Engineering Ccnrrpany Summesy RepoPts

P. Utah Construction Ccarrpmy

2. Bechtel Corporation

3. Kaiser Engineers

Selected References

2

4

6

9

15

19

20

23.

23

25

iii

1

INTRODUCTIQN

The purpose of th i s report is t o assemble the information acquired

t o date concerning the feas ib i l i ty of the Stanford site for the proposed

2-mile l inear electron accelerator.

review of the l i terature , photo-geologic interpretation, previous f i e ld

mapping, discussion with eminent authorities Fn the f ie lds of Seismology

and Earthquake Engineering, a,nd personal experience.

The report is based on extensive

The evidence assembled t o date eleaxly indicates that the proposed

s i t e is a feasible location f o r the construction of the linear accelerator.

However, further detailed work, including mapping, s o i l and rock testing,

subsurface dr i l l ing, and bulldozer exploration will be needed i n order t o

establish the specific project alignment and foundation conditions for

engineering design. In addition, in order t o establish engineering safety

factors that are commensurate with masombbe risk, eminent authorities

i n the fields of Seismology, such as D r . Perry Byerly, University of

California, and of Earthquake Engineering, such tw D r . George W. Housner,

CaLifornia Inst i tute of Technology, w i l l be consulted.

- 1 -

1

SUMMARY AND CONCLUSIONS

The study of s i t e feas ib i l i ty for a progeet such 88 the proposed l inear

accelerator requires carefuP consideration of project objectives, geograghic

location, topogmphfc situation, etnd specific geologic conditions with res-

pect t o possible prohibitive construction costs,and hwxrds which could in-

pair the usefulness of the proQect.

the follcrwing conclusions:

Ev&uation of these factors leads t o

1, The prqposed s i t e prQvides a very favorable geogra$hic location

close t o related research ac t iv i t ies at Stanford University and

available supply, power, and scient i f ic manparer sources.

2, The proJect requirements of tunnel length, tunnel cover, desir-

able side poptd., adequate reseeiPeh working area, and sound

stable foundations are d l provided by the proposed s i te ,

progect area is on available Stanford land.

The geology of the site does not offer construction hazards or

tunneling conditions which would signff icmtly alter conventional

design prwt ices o r t m e l i n g methods, which faetors together

determine construction costs, The site has been examined by the

Utah Construction Campany, Beehtel Corporation, and Wser Engi-

neers, and independently they reached the conelusion that the

s i t e was a feasible location for the prqposed pro3ecto

Earthquakes En the S m Francisco Bay Area are a recognized hazard.

Hmver, overwheMng empirical evidence proves that, a l t h o w an

area is hazardous, a minimum of danger exis ts t o properly de-

signed structures located on o r i n bedrock foundations.

San Frarncisco Region there are m o w r t a f n tunnels, a submarine

tunnel, numerous skyscrapers, and the B a y Br-fdges, all of which

The

3.

4.

In the

- 2 -

1

are earrthguake-proof structures.

matter of engineering design and selection of best possible

f ounbtions

The problem i s merely a

5. Earthquake damage t o tunnels rarely occurs. When damage does

occur, it is only t o imgrqerly designed, poorPy smoPted

tunnels, or i s Bn areas of incompetent rock fn steep mountain-

ous terpaAno

crossedby an active fault o r is Located i n the epicentral area

of the e&hqy&a,

designed Lo resist earthquakes and w i l l . be driven i n pe%atfvely

cmpetent PO& i n an meet of gentle tupogrrcphy.

faults cross the praposed t m e l site, which is located 4 mfles

from the neareot zone of k n m epfeen.-ters dcmg the San h b e t s

Fault.

involved i n building %he Ifnear ereeelerator at the proposed site.

*en then ckimage OCCUPS only when the tunnel is

The proposed t m e f wflf be specifically

No k n m active

Therefore, pj13 believe that there is er negligibfe r i s k

- 3 -

STTI3 REQUIREMENTS

"he s t ruetwes required t o house the proposed l inear accelerator are

described i n Stanfordffs Sni t ia l proposal of Mrjil, 1997, However, at that

time the desired s i t e requirements of the proposed structures had not been

defined, particularly the requirements which would insure optfmum uperat-

ing conditions. These requirements are smmarized below. It may be said

that the requlrements demand earefu9. geologic& evaluation, and dictate that

the site have particular topography.

The principal structures wilf be two pweit?lel level tunnels,

10 and 24 feet in diameter and 10,000 feet long. when em-

pleted, the tunnels SSfU be i n 24-how continuous use, with

personnel i n the larger tunnel at Cl times.

use, presence of personnel, and type of equipment demand p&ieu-

lwly safe tunnels.

personnel, equipment, ventilation, etc., wcl a c e n t r a y located

si& portal if at all possible.

over the tunnel t o insure safe radiation shielang.

The accelerator target w i l l be 'house8 i n a radiation-proof

structure which measures 400 feet by 500 feet, wfth 8-10 foot

thick walls q r p r o a a t e l y 100 feet high.

have partieularly sound, r igid beehock foundations, i f at a9p

possible

Pinpoint target accuracy w3th deviations of one inch per year

or f ive inches Over a period of y e a r s is desired f o r operating

convenience.

lems, but does dictate stable foundations fo r the t a rge t bufldfn@;

and the accelerator t m e P .

The continuous

There must be suitable t u m e L access f o r

There must be adequate cover

This s t m e t w e should

This requirement does not raise construction prob-

It should be eqphasized, hawever,

that the degree of s t & i l i t y stated above is desirable but not

critical. and t h a t deviation -up t o five feet can be tolerated.

There m u s t be adequate working space i n the target area f o r

present and future experimentaL purposes.

area should be enclosed i n an amphitheater valley, with steep

natural hi l ls ides f o r horizontal radiation shielding.

4.

IdeaIPy, the target

- 5 -

SITE FEAS%BIEITY FACTORS

"he proposed project s i t e i s on available Stanford l a d which has been

reserved f o r t h i s purpose,

related research act ivi ty at Stanford University, and geograghicalfy locat-

The s i t e i s located only two miles ao*h of

ed where power and strpplies, rn w e n as scient i f ic manpower t o plan, direct,

and staff the project are available.

The topography of the s i t e affords a suitable location for Level,

10,000-foot tunnels wfth upen poPta3.s on either end and et centrally located

side portal.

quate working space f o r d.l future needs and the excavation wi l l insure

sound bedrock founbtion for the target buffd9ng.

vides h i l l s ide radiation shielding.

location and tupography, the pruposed si te appears ideally suitea fo r the

progect. There yet remains the question of geological feasfb i l i ty of the

site.

The target =ea, wfth nominal excavation, WPPP p r d d e d e -

The excavation also pro-

In short, from the point of vim of

Investigation of geological feas ib i l i ty of tunnel s i t e s may be re-

solved t o specific questions concerning possible prohibitive construction

costs, and hazards that could impair the usefulness of the tunnel following

its completion,

regional and focal geology, and knowledge of project obgectives, engineer-

ing design limitations, and construction costs.

Satisfactory mmrs require careful consideration of

The relative fmpoP2;ance of the geological factors which affect the

ultimate construction costs, including corrective and preventive meamres

fo r hazards that are k n m t o be present, can vasy greatly. For example,

there is general agreement that with sufficient justlf ication a safe usable

tunnel can be designed t o counteract practfee2l.y any unfavorable geological

- 6 -

situation, from running quicksand and underground rivers t o solid granite,

The problem l i e s i n detectixg and defining the hazards that are involved and

the working conditions which will be encountered during construction,

Construction Costs

Tunnel construction costs may vary tremendously, depending on specific

geologic conditions.

significance of rock character and geologic structure w5th respect t o tunnel

&meter, excavation difficult ies, and roof support requirements. It is

necessary t o appraise the portal areas with regard t o access, working m a ,

muck disposa9, storage, and avaiP&ility of parer. Necessary contingencies

m u s t be included fo r unexpected excavation .and sugport diff icul t ies and fo r

extra pumping and ventilation i n case groundwater, natural gas, or high

tenperatures w e encountered,

It is necessary t o assess i n dollars and cents the

In the present case, the proJect $;pea has been examined by three recog-

nized engineering construction firms, the U t a b Constmetion Canpmy, B e e h t e l

Corporation, and Kaiser En@;ineers.

sidered different project, d.&pments i n the sane general area and, in each

case, reached the independent conelusion that the s i t e was a feasible loca-

tfon fo r the proposed project.

and explain the i r respective conelusions for permanent recopd.

conclusions are bound &s Appendix E,

For ccunparative purposes these finns eon-

The three firms were requested t o anpEify

Their summary

Tunnel H a z a s d s

The m a o r tunnel hazards, other than those which affect the tunnel de-

sign and construction costs, me limited t o phenomena which could render

- 4 -

the tunnel unusable a f te r i t s ccarrpletion.

These hazards are suarmarizedbelaw. The seriousness of any one is a

question of probability of oeewrenee, mmetm value of fntemvpted WWBm

tion, and repair costs:

1. Tunnel cobl;apse or fd lu re due t o forces of gravity causing

swelling or squeezing ground, or d m m d settlement of broken

rock.

Wor bedrock slides frm causes other than earthquakes.

Fault displacement across the tunnel.

M o r damage due t o earthquakes.

2.

3.

4.

!Tunnel failure due t o forces of gravity or bedrock slides is a c a s e -

quence of inadequate exploration and/or improper design,

be eliminated.

earthquakes require more serious consideration and are d.%seussed i n later

sections

These hazards can

The hazapds of fault displacement a d maor damage from

In the present ewe, there is the iddftiona9 possibil i ty of bedrock

deformation i n excess of the desired operating tolerances. However, t h i s

i s more of an operational. problem than a hazard which Plffects the f e m i b i l i t y

of the site, and it w%%l not be dfscussed i n this report. The possibil i ty

of such crustal deformation exeeedfng the allowable t o l e r a c e of 5 feet i n

a distance of only 2 miles is extremely remote.

NATURE OF EARTH!WUES

Earthquakes are caused by movements i n the earth 's crust. Minor

earthquakes m a y be associated with voleanie act ivi ty or landslides, but a91

large earthquakes are causedbythe movements of blocks of the crust along

deep-seated fractures c u e d faults,

sociated with movements along ma3or faults and usually originate at depths

of 10 t o 29 miles below the surface (lo)*+-

The destructive earthquakes are as-

The genera22.y accepted mechanism of fault earthquakes fs defined by

the "elastic rebound theory" proposed by Reid i n lgl0 (3u.)Jeo keording t o

this theory, the crustal blocks on ayIsosite sides of an active fault are i n

continutil. motion.

within the blocks. when the accumulated s t ra in exceeds the fric.f; iond re-

sistance dong the fault, a failure occws ayld the rocks on apposite sides

09 the fault snap back t o the i r original unstralned positions. This snap

ping action, and the rubbing due t o differentia9 movement of the rocks &on$

the fault plane, generate the vibrations that constitute an earthquake,

aftershocks originate i n the same way except; that the s t ra in of the m&s

i s accumulated quickly as a result of the movements along the master fault.

The point on the surface of a fault plane at w;hieh active slipping first

takes place is called the - focus.

immediately above the focus i s termed the epicenter.

determined instrumentaXLy, but it should be real ized that the energy release

and intensity of shaking may be distributed dong the entire active seg-

ment of the fault.

This movement causes bending or strafnfng of the rocks

The point on the surface of the earth

These points may be

*Numbers in parenthesis refer t o specific publication list i n &pen&x Po

- 9 -

The magnitude of an earthquake is an instrwnentfly determined gumti-

t y whieh was originally derived by Dp. Ce F, Richter t o measure the to t&

released energy. The intensity of an earthquake varies w5th location and

is a measure of the destructive power of the shaking.

scales are based on the arbitrary f?vduatia of the effects of an earth-

quake as defined by sensory observation and by the extent of damwe to

structures

The various intensity

The two types of destructive vibrations resulting from earthqwkes are

longitudinal waves (P) and transverse waves (S),

and radiate meuclemum energy along the plane of the fault.

The P waves are the faster

The slower S wave8

rad.iate maxSmum energy i n a direction perpendicular t o the fault plane (YO)*.

The destructive parer of the wave motion depends on the eglrplitude, frequency,

and duration of the vibrations, with the S waves g e n e r a y being the most

destructive, Close t o the fault f ine the P waves m a y be extremely destmc-

tive, but t he i r energy decreases rapidly may from the fault, For any

given wave, the amplitude of ground vibration varies greatly with the type

surface material t ha t is involved, and may be many tfmes greater i n &lznrim

than i n so l id bedrock.

may be 10 or 15 tfmes as great as that i n the underPyfng bedrock (see Ape

pendfx B)

The intensity of $haking i n water saturated a9pwium

Earthquakes may occur i n etny papt of the world but the m a o r destme-

t i ve earthquakes are concentrated i n two belts, one aSorpg the Meditemanem-

HimaJ.ayan axis, and the other i n the mountainous meas bordering the Paerfic

Ocean. The West aoast of the United States, and p&ieu%Eu”Sy California a9d

*Numbers i n parenthesis refer t o specific publication l i s t i n 83rpeniUx F,

- PO -

Nevada, l i e within this l a t t e r zone of activity. It has been estimated

tha t @ of the earthquakes in the world and gr$ of those i n the United

States (not indLudAng Alaska) occur in California and Nmada (2)*..

A t present, there is no way t o predict aecwately the time of oc-

currence or the magnitude of future earthquakes*

er ly (personal c ~ m i e a % i o n , &iLy 7, 1959), there is insufficient widenee

i n the his tor ical record t o support the theory of eye%fcd reoccurrence of

earthquakes i n any given locali ty,

earthquake i n a given wea m a y be evidence that dangerous accumulated s t r a n

has been released, but it is equal proof that %he area affected is one i n

which s t ra in has accmulated i n the past andl wil l probably accumulate in

the future.

i n an area of knam seismicity, a d a9eng the l i ne of a Iknm actfare fauft,

may be evidence of a dangerous s t ra in bui1d-q but it may &so i n a c a t e that

s t r a n is not accumulating but is being constantly Peleased by gradual fault

movements.

the solutions t o these uncertainties. A t the present time, huwever, the

problem of predicting earthqmkes, especially as it affects construction

progress, must res t on the assumption that the future will resemble the past

ar%d preventive measures must be taken accordingly.

According t o Dp. Perry By-

The recent oeemenee of a strong

In l i ke manner, the his tor ical absence of a severe earthquake

Future progress i n seismohgy euld geodesy&fE probably provide

Types of Ea&hqu&e Dmage

Damwe during earthquakes m a y result ei ther from the movements dong

the fault plane or” frm the vibrations associated wPth these mavemmtso

“RNtrm‘bers i n parenthesis refer t o specific publieation l is t i n Appendix F.

- E l -

AccordAng t o Dp. 6. F. Richter, of the California Inst i tute of Tech-

nology, throughout the World there are only &out 20 insteuaces of proven

surface rupture of bedrock which can be correlated wfth known earthquakes

Such rrzptures have occurred as featupes of only the most destpuc-

t i ve earthquakes and then only along the traces of faults which may be

recognized as having been active i n recent geologic time.

case, the actual movement &long the f a a t dies out before the surface is

reached.

r i f t ing and offsetting of roads, fences, pipelines, tunnels, dams mip other

structures which cross the trace of the fault,

severe but it i s easi ly avoided by locating structures may frm the traces

of lenown active faults.

In the usual

Pn cases when surface rupture aoes occur, damage win consist of

Such damage i s usuaUy

The strong vibrations of earthquakes m a y directly cause &anage o r

destruction t o structures and equipen$, o r they may trigger a variety of

secondary effects wZlich may also eventud.3.y result i n d

man. The usual sacmdary effects are Bandslfding, and in &LT_wierm or f i n e d

grOUld, slUUlpfq, lupchiw, a d formation Of ppeS8ILt% ?ddg@s. These l a t t e r

effects are distinct frm'bedPoeSc rqpture. Ladsl ides may occur i n areas

with deep s o i l cover, weak 'br&en or sheared rocks, s t e w tqpgraphy, md

water saturated materia3.. "hey w e caused 'by the force of gravity acting

on an unstable m a s s arrd are mem8y triggered by the earthquake vibrations.

I;eandsSides may uncover or crush %rnels, block r o d s md streams, QP cover

buildings. Landslides gener&Sy occpu" i n areas where past S%un&lf&ng has

left recogniz&le fea%u~es, Such meas should be avoided as cmstmction

si tes if at ekzJ possible.

"Numbers i n papenthesis refer t o specific publication l is t i n Appendix Fo - 12 -

Severe earthquake shaking of deep U u v i u m or a r t i f i c i a l f i l l ,

especiallywhen these are water saturated, may came differential set t l ing

or spontaneous fiquification.

cracks, ridges, .ad depressions, and i n the occurrence of slumping and

earth flow.

foundation preparation, such as piling md grouting, fs necessaryo

These phmamena result i n the fomation of

When h rge structures must be ’ b u i l t on ~XLwium, expensive

With an earthquake of given ehwacter and magnftude, the severity of

vibratfon damage t o a stPuctuPe WfPP depend prharfSy on three factors:

3.1

2)

distance froan the epicenter or from the active segment of the fault;

type of engineering structure; and 3) the geologic foundation on which

the structure is buil t ,

factor of distance i s probably the least c r i t i e d .

Within the apes of destructive intensity, the

In genera9, the resistance t o ewthqttl%ke Csaanesge is greatest i n mU-

designed structures of reinforced concrete eund least i n buildings of m-

supported masonry.

resist the horizontal accelerations causedby earth vibration. They often

incorporate design features t o demrpen structural vibration frequencies and

Parge structures mw include provision fo r differenti&. movement between

the i r various sections during severe shaking (IO) (8) ( 3 ) * .

Modern e&hque\ke-pmof structures w e designed t o

Fram the standpoint of ewthquelke resistant construction, the beat

possible foundation is sound strong bedrock and the worst i s water-saturated

dluvium, with a.l.3. gradations being found between these extmes,

portance of foundation is s h m by the mwy recoded cases of only slight

The im-

*Numbers i n parenthesis refer t o specffic publication f ist in kppendpx Fo

- 13 -

damage t o relatively weak frame and masonry buildings bui l t on bedrock

when, i n the sane earthquake, stronger s tmcturw bu i l t on dluvium were

seriously damaged or destroyed, even when the l a t t e r were at a greater as-

tance Tram the fault (90) (8)u.

*Numbers i n parenthesis refer t o specific publication l is t in Appendix F,

Many o f the mjar ezrt~hqwes of Cdifornis occur dong a belt o f north-

west tPenaLng faflts which extends from the h p e r l d Valley t o the Northern

Coast R a g e s . The Sawn Frmciseo B~qy Region f a tra,nsee$ed by severdl of these

major frw%weso The Hayward and CaLaverw faultf; extend thpou& the ewtern

p& of the Bay &ea and the San Andseas F a d t rum dEagond.3.y across the

S m Francisco peni,nsubo

under the sediments of the b@y and %he Swta C41ma VaXLey.

extend deep into the crust of the earth &nd a m major stmctwd fea tws

which we independent of smaller l o e d structures.

by observation o f offset fences, roads, stream, & ridge lines that the

movements on them faults i s essentially horizontal, wfth the block on the

west side o f the fault moving northward with respect t o the bloek on the east

side of the fault;.

ments by the United States Coast and Geodetic Survey but the e m % rate of

maremen%, &thou& about 2 inches per year 'between PObtS 40 t o 50 mf$es

apart, has not; been detemined accurately (15) (%6)*c.

There may be eenothelg large active fault buried

These faults

It has been established

These movements have been cQnt"imd by repeated meamre-

Them is e sn thua l seismic activity9 most o f it very minor, a-moeiated

with the fault system of the San Francisco B q r Region.

reeopized by Dr" Byerly (2)* as the sefsmricaU.y most active region i n

Gallifomfa and ha& been classified by Dra Richter (ab2)* as the most hazard-

The genera41 we8 is

ous earkhquake area i n the United States.

ni.zed, aand major engineering sP;ructms In the Bay &ea are designed t o

withstand the effects of strong e&hq&es0

This hazard I&; generaUy reeog-

The extent of seismric activity in the B ~ J Areamay be seen by e x a n -

ring the p lo t of epicenters bound in this reps13 as Appendix A. The

*Nmbers in p e n t h e s i s refer to specific pubaieation l is t in Appendix F .

- 15 -

larger earthquakes a m located near the mjor fault linea,, but the minor

lines that e a be mapped at the sWmeo This record o f epicenters ravea3.s

that the meas of greactes% seinsmle activity m e concentrated east of the

Bay and in the Smta C l a r a Va3,ley. The southem part of the S m Frmeisco

peninsula, w i t h i n a radius; 15 or 20 miles o f the proposed tunnel site, was

i n E868 etnd 1906 and were cawed by mwement on the H m and S a Andreas

FaCLts respc%ivelye Since 1906 some depmeege over limited areas ha8 been

Wze main fault trace. The 2.906 earthquake was by far the moat destructive.

Widespread damage to stmctmea seeurred throughout the region, ptxrtiedhsunw

About half? of the City of San Fsaei.sco =was destrcyed8 but only 20% of"

The remaining 8 6 resulted Prom the destruction was due to the earthquakeo

damaged were poorly designed, ~ O O X ? ~ J eomtxucted, and bu i l t on deep &rea%er-

satura%ed aJ-$ifieial f"fL.. Buildings on the rocky h iUs suffered compma-

*Numbers in prenChesis refer ts specific publication l i s t in Appndix F.

- 16 -

A distinctive feature of the 1906 earthquake was a 27O-mKl.e surface

rupture along the trace of the San Andreas Fault, which offset many natura9

and man-made features, The maximum horizontal offset was 21 feet. Two

brick-lined railroad tunnels, which crossed the fault i n the Santa Cpuz

Maunttxins, were offset and par t ia l ly destroyed,

shoek wave near the faxlt was sufficiently severe t o uproot oak trees and

snap the tops off redwoods (8)*.,

The intensity of the i n i t i a l

Stanford University is located 44- miles from the San Andreas Fault,

Most o f the builafngs were of unsupported masonry construction and were

bui l t on f a i r ly deep natural alluvium.

were scarcely affected, but the arcades and several of the 3- and 4-story

buildings suffered severe damage. Hmever, i n v iew of the unfavorable

cmbination of masonry construction and a l l w i a l foundation, it i s remark-

&le that the maJority of the buildings suffered only minor damage.

of the Stanford damege revealed that most of the seriously damaged build-

ings Were inadequately designed and poorly constructed even tm the extent

that inferior mortar had been wed (8)*.

The one- and two-story buildings

Analysis

As a result of the 1906 earthquake, engineering designs have been

developed which result i n vir tual earthquake-proof construction.

gineering works b u i l t i n the San Fr~~ncisco B ~ J Region since 1906 include

the Broadway and Twin Peaks tunnels, the Oakland-Alameda submarine tunnel,

numerous tall buildings i n San Francisco and Oakland, several tunnels of

the Hetch-Hetchy aqueduct, and the Golden Gate, Oakland-Bay, and Richmond

bridges

MaJor en-

*Numbers i n parenthesis refer t o specific publication l is t i n BLppendtx F.

- la -

As stated previously, the accurate prediction of earthquakes is im-

However, i n the San Francisco Bay Region, possible with present knowledge.

with i t s history of earthquakes, seismic activity, and measurable crustal

movement (2) (6) (l5)*, it may be stated positively that major earthquakes

w i l l occw i n the future, but that the time of occurrence is indeterminate.

It m a y be assumed that the intensit ies of future emthquakes can be similar

to, but will not exceed greatly, those of the 1906 earthquake,

*Numbers i n pasenthesis refer t o specific publication l is t i n Wendix F.

- 18 -

EFFECTS OF EARTHQUAKES ON TUNNELS

Review of the l i t e ra ture thus far has revealed only a few instances

of earthquake damage t o tunnels, principally railroad tunnels, affected

during the 1906 San Francisco earthquake (8). and the 1952 Kern County

earthquakes (lo)*. A more exhaustive survey of world-wide occurrence of

earthquake damage t o tunnels by C. M. Duke and D, J, Leeds, i n an unpub-

lished report f o r the second RAND symposium on protective construction,

described two other cases.

Japan during the 1923 Tokyo earthquake and the 1930 Tanne~ earthquake.

all of these cases, the damage occurred t o unlined or poorly supported

tunnels o r t o reinforced tunnels driven through inccmrpetent broken rods i n

areas of steep topogrqhy. In each case either the active fault producing

the earthquake passed across the tunnel, or the tunnel was located i n the

m e d i a t e epicentral area of the eesthquake.

These inurolved damage t o rai1r.d tunnels i n

In

It i s significant that there are several reported cases where m a o r

earthqudce damage occurred at the surface, while miners working beneath the

same area did not even notice the earthquake (3)*.

instrumentally that the amp3.itude o r displacement of certain types of earth-

q W e vibrations exhibit a marked decrease i n depth.

types of materials involved, the r a t io displacements m a y be as great as

10, o r even 2.5.

It has been confirmed

Delpending on the

In this respect, the summary and conclusions i n the RAND Symposfm

report are psrtinent t o the appraisal of tunnel s i te feasibility.

of the report i s bound as Appendix B.

The 23ext

-

*Humbers i n parenthesis refer t o specific publication l is t i n Appendix F.

- 19 -

A par t ia l l i s t of California water tunnels i s bound as Appendix C.

The l is t w a s obtained frm the California State Department of Water Re-

sources and includes only tunnels over 1,OOO feet i n length; it s h m the

tunnel name, location, bore, length, and date ccrmpleted. A similar l is t

of highway and railroad tunnels i s being ccanpiled.

There are over 100 maor water tunnels i n the state, totaling over

Many of these tunnels are located i n particularly 300 miles i n length.

hazardous earthqudce areas, and have experienced strong earthquake vibra-

tions. A number of the tunnels cross k n m active fauPts.

cant that there are no known cases of fdlure i n these water tunnels due

t o earthquakes.

It i s signifi-

The LOB Angeles Metropolitan Water District owns and qgerertecs 142

tunnels totaling 43 miles i n length; the Pacific G a s and Electric Campany

owns and operates 73 tunnels total ing 143 m i l e s i n length; and the San

Francisco Metrqpolitan Mater District owns and operates 34 tunnels totaling

76 miles i n length. None of these c q a n i e s have ever experienced signifi-

cant earthquake damage i n the i r tunnels (See Appendix B).

According t o Ms. J. H. Turner, Chief Engineer and General Manager

(personal ccmnunication, July 19, 19591, the Saen Francisco Water Depeu"tment

owns and operates 29 tunnels i n the Bay Region, U wPthin 50 miles of Sarn

Francisco.

lined,

damage, despite the fact that several were located only a short distance

from the San Andreas Fault.

Many of these tunnels were b u t i n the 1870's and are brick

These old tunnels went through the 1906 earthquake and sufferdl no

Regional Geology

The proposed accelerator s i t e is located i n the gently roll ing foot-

h U s dong the eastern side of the San 29?apnciscopeqinsuEa..

ing area is characterized by northwest-trending topography which roughly

ref lects the structure and cp$stt;pibutian of the underlying rocks.

*or fea twe of the region is the S a Andreas Rift Zone wbich lies i3p-

The smound-

The

prox2mately four miles southwest of the project s i te ,

north-northwest diagonally a c r o s ~ the San fianeiseo peninsula.

and structures on apposite sides of the S a Andreas Fault w e dis t inct ly

different. Since no structures extend acrose the rift, only the geology

east of the zone is described i n th i s report,

This zone exknds

The rocks

The oldest rocks in the region are of Jurawie age and belong t o the

This formation is amaJor unit i n the Coast Ranges Franciscan Foxmation.

and is chapaeterized by ccmplex structures and a v e r s e rock types. In the

western part of the area these rocks are at or near the surface and i n the

eastern pa& of the area are overlain by folded sandstones, shales, lime-

stones md favas of Ter-biary age.

latter rocks.

The tunnel will be driven through the

The mqor s t ruc tu rd features i n the western pa& of the area are

strongly developed branching faults which iiiverge frm the San Andreaw R i f t

Zone and extend southeast across the areap

faults passes wfthin I.+ miles of the project s i te .

the eastern part of the mea are moderately folded and are cut by faults

The newest of these large

The Tertiary rocks i n

which &..so trend northwest t o southeast. These latter faults are Peas w e l l

developed and l e s s continuous than the parallel faults t o the west.

mea is bounded on the east by the aXLrrvSetS E Q P ~ bodering S8wa Fpmcfses Bay.

The

- 2 1 -

Locdl Geology

The s i t e geology wa8 mapped by Stanford graduate students i n 1956 under

the supervision of Prof, Bo Mo P w . The m a p p i n g includled ear l ie r work by

the m i t e r , Frank Atchley, The geologic report is bound as Appendix D.

The principal roeks i n the area consist of rePativePy weak shales and

sandstones unconfomably overlain by 8; local sequence of hard resistant

basalts and weak volcanic agglomerates. These volcanics, i n turn, are

overlain by massive fritib3.e

These rocks are of Tertimy age and, althopgh t i l t e d and folded, are rela-

t ive ly undefomed.

generally f m d elseuhere i n the Coast Ranges, especially i n the serpentirnes

and deformed rocks of the Franciscan Formation.

sandtstones eula lenses of hard sandy Ifnestone.

They win provide be t te r turnnelfng conditions than

There undoubtedly wi l l be l o c d , troublesane shewed zones which m e

concealed, but generally spe&ingl the rocks are sound and ccaapetent.

The over-all structure i n the emtern half of the area is an eroded

plunging anticline or dme which is Pocalpy modified by faulting. Structure

i n the western half of the area is essent fd ly a t i l t e d succession of strata

dipping generally 35-60 degrees t o the south and forming the south limb

of the anticline. There are a t l eas t three dfsemtinuous faults i n the

general area, but only one of these is knm t o cross the presently pro-

posed tunnel l ine,

The tunnel l i ne passes under the plunging end of the dame through

more or less horizontal strata and then continues wes tward , crossing the

t i l t e d strata at an oblique angle, The principal rocks *ich wi l l be en-

countered w i l l be shales and sandstones, - 22 -

appRarSaL OF PROJECT HAZABDS

The proposed progect d%9. operate on a continuous 2bhour basis and

there will be personnel at work i n the control tunnel. at a l l times. There

wfll be expensive delicate equipment and rather heavy machinery located i n

the tunnels and target bufldfrigs,

interruption would involve large monetary loss.

Once the accelerator i s i n operation, an

The & m e features require p&i@Uparly s&e tm4s and necessitate

concrete l ining throughout,

possibi l i ty of tunnel eoETqse, or rock elities i n the por t a l areas.

the only natural hazard which could interrupt the operation is m a o r earth-

quake damage.

adequate design measures WfPP insure rsg&.nert the

Thus,

Ea.rthqWe damage may result from severe sh&- or fran f a d t &s-

placemento

on the surface, o r t o equipment within these stmctures,

damage would be direct fault offset across the tunnel, with displacement

greater than tha t which could be counteracted by m u s t i n g the accelerator

mountings. The next greatest hazard would be severe damage frcm toppling

equipment, cracking of tunnelwaUs, PocPLY corPqse, or stncturetf dennage

at the surface.

Damage cauld occur t o the tunnels, t o the txppurbenant bCLdfngs

The worst possible

Regarding the possibil i ty of f a d t &8Splacement, it has been shown tha t

throughout the world there axe only about x) established ewes of $wface

bedrock rupture accoMpany3ng an earthquakeo Moreover, there have been no

knw instances of bedrock rupture except along the trace of recognized

maor active fault zones,

have been dong the Hayward Fault in the I868 earthquake and &Long the

Sari AnaPepzs Fault i n the 1906 earthquake.

In the Bay k e a the only puaowln bedroek q t w e s

This evidence fnaca te s that

there i s but slight chance of a new fault break ever occurring i n &y

given small mea, particularly i f no active faul ts cross the ares.

progect area, m a p p i n g has revealed the presence of one fault crossing the

proposed tunnel l ine.

place on these faults i n his tor ical or geologically recent time.

on t h i s evidence, it m e a m that the hazard of fault displacement across

the tunnels is negligible.

In the

There i s no indication that movements have mer taken

Based

Regarding the possibil i ty of earthquake -age due t o severe shaking,

it has been shown that the danger of damage t o properly designed tunnels i s

l e s s than the danger of damage t o structures on the surface,

t i cu la r ly so -&en the tunnels are not crossed by active faults. ?he most

l ike ly hazard would be frm toppling and shifting of machinery ana equip-

ment within the tunnels, 'chis danger can be minimized by the use of prcrper

mountings.

collagse o r cracking of the tunnel waEls, is quite smal l at the proposed

s i t e because of the presence of coxpetent rock and gentle topogrscphy.

This is par-

The danger frcun rockslides and shifting rock, which could cause

Minimizing the danger of earthquake damage t o surface structures is a

matter of selecting the best possible foundkttions and then designing accord-

ingly.

structures are founded on bedrock.

t o e s t b a t e the horfzontal acceleration that could result frm an earth-

quake of expectable magnitude and establish a seismic factor of s a e t y

that i s commensurate with reasonable risk,

The present planned tunnel afignment is such that alp cr i t ic&

For stmcture design, it is necessary

A,

B.

6,

Do ENGINEERING GEOLOGY OF THE PROPOSED SITE OF PRcaTECT S!FANMIRD,

W OF EARTH&UAKE EPICENTERS IN THE SAN FRANCISCO AREA

EFFECTS OF EAFiTHQUAKES ON TUNNELS, by Do M, Duke and Do J, keds

LIST OF CALIFORNIA WATEI3 “ D E L S

CALIFORNIA, by H, C, L m g e r f e l d t and L. We Vigrass

E, ENGINEERING COMPANY SUMMaRY REPOETS

1. U t a h C o n s t r u c t i o n ccanqpany

2, Bechtel Corporation

3. Kaiser Engineers

F, sEUcTEI>IIEFEI.IENcES

- 25 -

APPENDIX A

APPENDIX B

EFFECTS OF EBRTH&UAKES ON TUNNELS

by C. M. Duke and D. J. Leeas*

(Manuscrfpt d r a f t without i l lustrat ions)

Introduction

effort is made here t o summasize a d generalize the available infomation

on e&hqu&e damage t o tunnels.

sented, lalong wlth supporting and indirect evidence.

anif of the geology are less ccarrplete than i s desirezble, but the fac ts wailable

w e a r t o w a r r a n t several. useful generalizations.

Four reasonably w e l l documented eases are pre-

The details of the failures

The original sources cited may

be consulted by those wishing t o study the data i n detail.

Experience i n California and Japan

Central California, lgO6.

dam@ged tunnels on the netrPar-gage Southern Pacific Railroad between Los Gatos md

Smta Cimz. %he 6200-foot tunnel at W r i g h t Station was crossed by the Setn Andrees

fault and the 5”7O-f00t t m e l directly t o the south w a s a lso damaged, but t o a

In the San Francisco earthquake of 1906 there were two

smmhat lesser degree.

designate& PO on the Rossi-Fore1 scale. Damage t o the tunnels themselves, Table I,

corisisted of the caving i n of rock from the roof and sides, the breaking i n flexure

of upright timbers, ewd the upward heaving of rails and breaking of ties.

Shaking at the surface over the tunnels was very intense,

Both

tunnels were blocked at a number of points.

The tunnel at Wright Statlon suffered a 4.5 foot transverse horizontal offset

where the fault cut it. See Fig. P. This same movement wrecked t h e Morrell house

which stood above the tunnel and on the fault. Tunnel damage w a s greatest wound

the offset and at the several locations where pas&Llel fissures Were in evidence.

-

* Respectively Professor of Engineering and Associate Research Engineer, University of California, Los Angeles,

- 2 -

The rocks i n the WrSght tunnel looked Pike sandstones and Jaspers of

Franciscan age

Other tunnels on the Santa Cruz-Los Catos li.ne were undamaged, except f o r

two eases of broken tfnbers.

Pine, i n southern S m Francisco, were uninjured.

New tunnels mder construction on the Bayshore

Tokyo h a , Japan, 1923. The great 1923 earthquake dgnnagad about 25 tunnels,

Table 11, i n the vicini ty of Tokyo, principally on the Izu eznd BQSO penintpulw

which w e the mainland areas elosest t o the epicenter.

t o shaking, as no case of faults intersecting the tunnels i s k n m .

The damage i s attributed

Most of the

%umePs were concrete o r brick lined, with depth of cover, character of rock,

Length, and other features vzitqctne: over a rather wide range.

tumal damage occurred in the OdizwaJI.a-Atermi-H&one region, which suffered the

highest intensity of shaking.

50% of houses eol lqsed, tunnel damage apparently wa6 insignificant.

PetrticuPwIy heavy

Beyond the isoseima9 corresponding t o approximately

Figures 2 through 6 i l l u s t r a t e the destruction in two selected cases. Damage

varies frm fractured por ta l masonry through cracked linings t o caveins Tram roof

md sides.

Tanula, Jqasn, 1930. The Tanna Tunnel, connecting A t a m i and Mishima, was under

construction during the IZU earthquakes i n 1930.

of the &&in tunnels which extended ahead of the main tunnel heading, causing a

transverse horizontal offset of 7.5 feet at a distance of about two feet beyond

the main tunanel heading.

few era&s i n the wd2. s .

basin 160 meters &me the tunnel, 55% of the dwellings were thrown dam, a d b$

of the houses were destroyed at the nearby villages of Tcmm~. and Rata.

displacements on the fault occurred m e r a distance of 15 killmeters.

The Tanrna fau l t intersected one

See Figs. 7 euld 8.

But i n the viPlage of Karuisme, Bituated on the Tanna

The on ly damage t o the t m e l wet8 et

SuPface

- 3 -

The Tanna basin i s a lake deposit of sandy

meters deep? overlying andesite and agglomerate

Kern County, California, 1952. The K e r n County

clay and boulders, about 40

through which the tunnel passes.

earthquake of 1952 severly

damwed four tunnels, Table 111, on the Southern Pacific Rlzilroad near BeKLville,

about 15 miles northwest of Tehachapi. This was the region of largest observed

ground fractures associated with movement on the White Wolf fault. See Figures

9 and PO. In all, there were l 5 tunnels between Bakersfield and Tehachqi, eLnd

those outside of but adjacent t o the area of ground fractures suffered slightly,

t o the extent of opening of construction joints.

b u i l t fn about 1876, with timber l ining i n the tunnels.

l ining 12 t o 24 inches thick was installed later, without removing the timber.

Rock around the four damaged tunnels w a s a fa i r ly easily excavated decomposed

diorite.

The railroad i n t h i s area was

Reinforced concrete

Tunne l No. 3, originally 700 feet long, was heavily damaged at i t s Tehachapi

end, 200 feet of which w a s daylighted after the quake. See Figs, 11 and 12.

A t one place the buckled rail extended under the concrete wall, indicating that

the w a l l had raised sufficiently t o permit this .

found direct ly over No. 3, an active fault crossing the tunnel was found during

daylighting.

While ground cracks wer@ not

Large surface cracks, Fig. 13, were found above No. 4, which was badly

shattered, Fig. 14, and subsequently daylighted fo r i t s full length.

Tunnel No. 5 w a s very heavily damaged, Fig. 15, but was reconstructed without

<1aylightPng.

from these cracks flowed into the tunnel.

Craeks and holes appeared in the ground above, and rock and s o i l

Broken l ining ecnrrprised the damage t o No. 6, Fig. 16, which was daylighteed.

No substantial surface cracking was noted over t h i s tunnel.

- E c -

These tunnels were in the region of heaviest shaking, Modified Mercalli

Intensity 11, but clearly the extensive damwe w a s primarily due t o their

location i n the fault zone.

krkui 1948 and Hokkafdo 1952. A t Kumasaka, north of Kanmu, the porta9 arches

of a brick-lined tunnel were p a r t i d l y fractured in the 1948 Fukuf earthquake.

Apso i n t h i s earthquake, et large concrete culvert was badly cracked at midlength.

In the 1952 Hokkaido earthquake, mfnor cracking w a s induced in the w a l l s of

one concrete-lined and one brick-lined tunnel.

Fault movement at the tunnels w w not involved i n the above cases.

Related Experience

Mines and Caves. k i n g the Sonora earthquake of 1887, an engineer was i n a

mine at Tombstone, Arizona.

but no collapsing, down t o several hundred feet of depth.

timbered,

shifting of engines on the i r foundations.

He f e l t violent shaking and observed ma91 rockfalls,

Most stopes Were w3-

Damage on the surface consisted of fa l l ing plaster and chimneys, and

In another case, i n mines at Butte and Barker, Monteula, the 1925 edhquake

was hmdlly noticed by those underground but was f e l t at the surface.

The August 22, 1952, Kern County aftershock was reported not t o have been

f e l t by a party in Crystal Cave, Sequoia, but t o have been shhuply f e l t by persons

outside the cave.

There appears t o be a possibil i ty that rock bursts at Widwatersrand, South

Africa, may be triggered by releases of energy at points i n the mine ccmplex

away from the bursts.

Experience of California Agencies. Correspondence from W. M. JaekSe, Chief

Engineer, Southern Pacific Campmy, reveals that, except for the 1906 and the 1952

eases, no damage or disturbance t o Southern Pacific tunnels has been caused by

eetl-thquakes.

- 5 -

The Los Angeles Department of Water and Power operates t h e Owens Valley

Aqueduct, wbich includes 14.2 tunnels totaling 43 miles i n length.

was cmpl@ted i n lgll. , and no tunnel damage due t o earthquakes has occurred.

The E l i z a e t h Tunnel, f ive m i l e s long, crosses 3000 feet of the Sm ArndPeas rift

zone at a depth of up t o 1000 feet .

damage has been found t o date.

The Aqueduct

It is inspected annudly; no earthquake

The Pacific G a s and Electric Campmy has experienced no significant eeu%hqu&e

deanage t o tunnels i n i t s b yews of experience with 73 tunnels, unlined and concrete

lined, totriling 3-19 miles i n length.

The above experiences are significant i n view of the fact that California has

experienced severe earthquakes i n 1915 (Inrperid Valley), 1925 (Smta Bwbmaa),

2933 (Long Beach), l9h.O (El Centro), 1952 (Kern Cownty), and 195k (Western Nevada),

in addition t o the great earthquake of 1906.

Effect of Depth below Surface.

earthquake motion at same depth and simultaneously at the ground surface.

(1902) was the first t o make such measurements,

displacements of 14 earthquakes at the surface above Tmna Tunnel and i n the

tunnel at 160 meters depth t o be 4, 2, 1.5, 1.2 f o r periods 0.3, 1, 2, 5 seconds,

respectively,

agglomerate at depth. Saita etnd Suzuki found that the m a x b u m acceleration at

the surface of a 68-foot layer of aXluvium w a s three t o f ive times that at i t s

base contact with dilwfm, Tnouye found that short-period waves (ripples) observed

at the surface were largely absent at a +meter depth.

Severtit Japanese investigators have measured s m d l

Bmori

Nasu determined the rat ios of

The ground w a s lake deposits at the surface and euldesite end

Carder of the U.S. Coast and Geodetic Survey recorded approximately equal

amplitudes of microseisms at the surface and at 5OOO-foot depth in Homestake Mime,

Microseisms were of four or f ive second period.

P-waves of one-second period were recorded at 300-foot depth with twice the

In a l a t e r study, earthquake

- 6 -

amplitude recorded at 5000-foot depth.

Recently, Kan& has made signal progress i n t h i s field. He operated seismo-

g r q h s at depths of 0, 150, 300, 450, and 600 meters i n a copper mine i n Hftachf

and recorded a very Parge number of smell earthquakes. The ground is paleozoic

rock, wfth some weathering near the surface. The r a t i o of surface maximum a s -

placement t o that at 300 meters depth w a s about 6 at the mine a d about BO at a

e;chool 6 PrSPmeters may on allwfum.

earning waves w w d o s e t o the free period of the surface layer caused these

maximum ratios, but many earkhquakes occurred for which the ratios were as maPP

as one-third of the above,

waves ( ripples 1, found on surface seismograms but not underground, corresponds

t o the predominant period of the surface layer; the ripples aminated the surfme

record when the incoming waves contained ccmrpomts w9th period equal t o that of

the rfpples.

formulas of Sezawa and Kma9.

Earthquakes whose average period of 9n-

He also found that the period of the short-period

These findings support quantitatively the theoretical amTpPification

Qualitatively, these researches demonstrate eqerimentalPy the following

effects of depth:

a. A t short periods, surface dfspPacments are larger than wndergrounb a s -

placement s.

The r a t i o of surface t o underground displacement aepends on the type of

ground.

rea& -a v d u e of at least PO.

For wave periods over one Becond, the ra t io becomes cmpwatively smd-1,

approachfng unity as the period increases.

There is a particular average period of incming waves f o r which 8 given

type of ground w i l l provide a maximum r a t i o of surface t o unc9ergromiI

&splacement.

mately equd t o this p&fcuPar period, the ra t io w i l l be m a t e r i d y m&Qer.

b.

It is greater for alluvium than for weathered rock. It may

e.

a.

If the average period of incoming waves i s not approxi-

1.

2.

3.

4,

5.

Generalizations

Severe tunnel damage appems t o be inevitable when the tunnel i s crossed

by a faul t or faul t f issure which slips during the earthquake.

In tunnels may from fault breaks, severe damage may be done by shaking t o

linings and portals and t o the surrounding rock, f o r tunnels in the epicentral

region of strong earthquakes, where construction is of marginal qudi ty ,

SChstmtid reinforced concrete Pining has proved s q e r l o r t o plain eanerete,

masonry, brick, and timber i n t h i s regard.

Tunnels outside the epicentral. region, md well constructed tunnels i n th i s

region but away fram fault breaks, em be expected t o suffer l i t t l e or no

damwe i n strong earthquakes,

While it would seem reasonable that competence of the surrounding rock would

reduce the likelihood of damage due t o shaking, inajdequate camparative

evidence i s avai1ahJ.e on t h i s point.

Within the usual range of destructive earthquake periods, intensity of

shakiw below ground i s l e s s severe than on the suP1Face.

References

Cdifornia Earthquake 1906

Gilbert, G. KO; EharrphPey, Re L.; Sewell, J. S.; Soule, F, The San Francisco

E&hqua&e and Fire of April 18, 196 axid the i r affects on Structures and

Structural Materids. Bull. 324, U. S. GeoP. Survey, 170 pg., 54 @Lo (1907>.

Specid. Committee, MCE. The Effects of the San Francisco Earthquake of

A p r i l l8th, 196, on Engineering Constructions. Trans. ASCE, - 59~208 (I907).

State EaPthqudcs Investigation Commission. The California Earthquake of

& r i p 1.8, 1906, Gamegie Inst. of Wash., Publ. 87 (3-908).

- 8 - Tokyo &ea 1923

Okmura, Mataichi (Edi tor) , Report on the Damage Caused by the Kanto

Earthquake of 1923.

volumes (1926) I)

(Japanese, ) Jagan SOC. Civ. Engr,, Tokyo, three

Pmperial Earthquake Investigation Cammfttee. The G r e a t Kwanto Earthquake of

Sept, 1, 1923. (Japanese. 1 Reports 100 and 100D, pp. 215-233 (1926)~

Izu Earthquake 1930

Otuket, Y. The geomorphology and geology of northern Idu Penbsula, the

earthquake fissures of Nm. 26, 1930, and the pre- and post-seismic crust

deformationso BuPT. ERI - 11 :53O-$'j'k (1933)

Masu, No Kfshinouye, F., and Koda;fra, T. Recent seismic ac t iv i t ies i n the

1611 Peninsula. Part 1, ERI - 9:22-35 (1931).

Richter, C. F. Elementary Seismology. Freeman, San Francisco, ppo 57842(1-958Q.

Yamaguti, S. Deformation of the eapth8s crust i n Pdu Peninsula i n connection

Bull.. ERI - l5:899-934 with the destructive Idu earthquake of Nov. 26, 1930.

(1937d.

Otvka, Ye The geomorphology of the Kmo-aawa aU.uvial plain, the e&hquake

fissures of NOIT. 26, 1930, and the pre- and post-seismic crust deformations.

BrxLT,,, ERI _I lO:235-2k6 (1932).

Tsuya, H, Om the geological structure of I t o d is t r ic t . Bull. ERI - 8~409-426'

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T&&-mi, R e Results of the precise levellings executed i n the T m a railway

tunnel and the mavement along the slickenside that appeared i n the tmmel.

B U o EBI - 9~435-453 (1931)

- 9 -

Kern County Earthquake 1952

Southern Pacific Company. Earthquake Damage t o Railroads i n Tehachapi Pass,

Part 111, Paper No. 6, Calif, Dfvo Mines BuEP, - ln:243.-248 (3.955)

Kupfer, Dondd H , ; Muessig, Siegfried; Smith, George Lo; White, George Ne

8min-Tehachqi Ewthqwike Damage Along the Southern Pacific Ra i I rod

M e a BeaSLviUe, Cd..ifomia. Past I, Paper No. 7, C a l i f , Div. MAnes BeiEP.

- In. :69-74 (1955 0

Buwddtt, John P. and Pierre St. h a n d , Geological Effects of the h i n -

Tehachapi Earthquake. Part I-V, C a l i f . Dive Mines Bull. - I7l:41-56 (3.955).

Steinbmgge, Karl, V, ana DonaJld F. Morm. An Mineer ing Study of the Southern

California Easthquake of July a, l952, eula Its ZSStershocks. Bull. SSA

- 44~201-lc62 (1954).

m u i 1948 ma Hoaaiao 1952,

Special Investigation Camittee of Tokachi-oki Earthquake, Report on t h e

Tokmhi Olci Earthquake, Hokkaido Japan, Marc91 4, 1952.

Published by the Speeid Cammittee for the Investigation of the Tokaehi-lOki

Earthquake, Sappore, pp. 6-29 (1954),

(Jqa’ese.)

Far E a s t Cammad, General Hedquaz-ters, Office of the Engineer. “he Fuka

Earthqudce, Hokwiku Region, Japan 28 June 1948. VoP. 11: Engineering, p.30.

Pardee, J, To The Montana Emthqwke of June 27, 1925, U. So Geo3.ogfeaz;k

Survey Professional Paper 14q-B, pp. 7-23 (1926),

Effect of Depth on &qilitude

Inouye, Win. Cccmrpetrison of E&h Shakings above Ground md Un:dergromd,

BifkP. ERI, - X?:n2-7kL (193k).

Safta, Tokitaro and Masasi Suzuki. On the m e r Surface and ’Underground

Seismic Distwbmces at the D m Town in Tokyo. (Jaganese.) B u l l . ERI

_I 12 :517-526 (1934)

Nasu, N. Comparative studies of earthquake motion above ground ewld i n a tunnel.

P& I, Bulle ERI - 9:Ec54-442 (3-933.).

Capaer, Do S. Seismic investigations on the 5000 foot level, Hmes%&e Mine.

L e d , So D. Ea3tthquake Notes, Vol. a, pp. 13-14 (3.950).

Kanai, K. anti. T o Tanaka, Observations of the earthquake-motion at the different

depths of the e&he BuPL ERI _r/ 29:107-13 (1951).

K n a a i , KO ; O s d a , KO ; Yoshiziawa, S.

i n the Depth o f the Gromd,

Surface arid the Period. )

Observational. Study of Earthquake Motlon

(Relation between the hp1itu&2 at Ground

BaaEP. ERI 31:228-234 (1953).

Kand, KO; Osda, KO; Yoshizawa, So

i n the Depth of the Ground, V.

Motion. 1

Observational Study of Earthquake Notion

(me P-PobPm of the R i p p l e of Earthquake

BdP, ERI - 32:362-370 (1954),

The TolPcwtng l i s t of Cdiformia S - a k L s was obt&i-ned from the State Divisfon of Water Resources, not e q 1 e t e . nels i n existence over 1,000 feet i n length.

It is 8 par%i&L P i s t of water tunnels only, and the data is It is estimated there are approximately 50 highway and railroad tun-

N M

G L b r d t a Reservoir June& Reservoir Mono Crater Tecolote K € T e w l W Pit No, x Pit No, 3 Pi t 5 No. 5 Pi t 5 No, 2 Pit No. 4 Bdeh Bucks Creek No. B Bucks Diversion Melories Drum C a n a l Noo 1 Tiger Conduit Stanislaus CoPgate Oleum Dutch Flat NarPOWS T abe aud. West Point EYectrez Crests Ro& Creek Be= River Dm B e a r River H€?X?ihriellrS Wf shon Poe Butte V%PEey Cwi'b0u No. 2 Has8 Contra Costa No, Y Lake Mereed Seuv P&lo Clmemont WKLnUt Creek Feather River

LOCaTION

rm Seunta Barbma TYP S m t a Barbma rn Leviruerlg m Smta Barbara fiesno comty Shwta Comty

I1 I?

I? If

at t?

f l 11

Fresno County psmw county Pkumas county

0 1 Nevada County BLaadOP comty Tuol~nme County Yuba County Contra Costa macer County Nevda County

( 7 ) AmEdor County hador counuty Butte County P3-mm Comty hador county Placer eouzlty in sierra M~S. ( 7 1 Mdera County Butte County Lmsen ciomty mumas county Fresngs County Contra. Costa County

Contra Costa County I1 !I 11

I! I ? 1Y

mumm couplty

LENGTH

6 miles 4 miles 59,8r3 f t 4

33,557 8,350 YO, 000 20,900 5,837 23,161 21,434 19,000 99 330 5,750 4,960 3,350 3-49 350 59,308 24,674 2,578 299 755 1,056 2,869 1% 333 43,062 20,903 34,019 1,095 13,249 4,620 =,038 3 2 , w 10,899 8, no 32,854 1 9 360 2,700 3 miles 5 miles 2,500 f t , '7 mfles

NAME L O C M I O N

CoPorado River Aqueduct System

CO%O~&Q River various CooJarn Basin Whipple M t . Iron &E, E a s t & West(2) cocks Cmb E s t Eagle System (3) Hayffeld No, S. & 2(2) cottonwooa Mesa Pass m d CochePla

Uvetsiie sarn Jlzcinto

11

I t

I1

11

I1

11

system (no) ( 1 11

I t

S m Diego Aqueiiuet System

Ranibm vEwious Red Momtain O a k H f U B W Y Five H i P l Sarn Vieente

I t

11

11

11

I 1

Hetch Hetehy Aqueduct System

Sierra Divisforn vmious (essent idny one tunnel %&Lh short gaps)

( e s sen t id ly one t m e n -with short gaps)

Coast Division 11

l4mmoth Pool. Aqueduct System

Florence various FEoPence Lake No. 2 Big Creek lhI t I lO. t 'n I 1

I 1

I t

Owens Valley Aqueduct System

3 tunnels 0)

DATE

1939 11

11

I1

11

I t

11

11

194.6 1949 1947 1947 1946 1946

various

11

BOlSE

19 11

11

I t

11

11

11

11

11

I1

I t

140 x 14g

14O x

ry x 15* 21 24 9'

12

LENGTH

1 mile 1 7 8 3 7 3 4

20 8 3-3

k,700 ft. 3,078 3,590 3,180 5,700 27455

99,264 ft.

1507480

55,984 ft.

c-2

under supervision of

Dr. B q M. Page, S%&opd uinivelpsity

December, 2.956

CONTENTS

Page Swmmarya.nd.~ecammendations e e e e . . e D-f

Introduction &nd puspose . . e e D-2

Presentation of" data and interpretations . e e e . e D-3

Los Trezneos formation a e . . . e . . . D-4

Engineering propePties of the rocks e . - e . . . . . D-6

Excavation e e e . e e * . e ., . D-6

ENGINEERING GEOZOGY OF THE PROPOSED SITE OF PROJECT "M"

STAlXE'BRD, C B L I F O R N U

SUMMARY AND FG3CBMMENDATIONS

In the &rea proposed as a site f o r Project "M", Eocene sandstone, mudstone and ehee'le dip steeply southwesterly and acre bounded t o the west, gsouth and east by more gently dipping miocene basalt, fragmental. volemic rock, limestone, sandstone and minor shale. Several faults, showing no evidence of recent movement, cut across t h i s semi-damaf estmcttere

From et, @o[Ecgic viewpoint, the site ha8 no serious engineering problems. T u n n e l support -11 be required, but running ground is not anticipated i n the tunnel section. dip of the beds into the slope. but no serious flooding problem is expected.

Indications &re that blslerting costs will not be excesnsive.

Danger of landslides is minimized by the general. Groundwater may be a problem locafpy

Since the geologic data presently available is inadequate f o r a report which is i n any way complete, it is recommended tha t an explora- t ion program designed t o tes t the engineering properties of the rocks t o be cut or tunnelled be undertaken before construction plans ere finalized. It is further recormended that the areas selected f o r use

fin materid be test driUed prior t o final location of the borrow p i t s .

D-P

INTRODUCTION AND PURPOSE

This report; covers the pology of an area o f t h e foothi l ls west of S%anford. University c a m p which has been tentatively selected as the s i t e fo r the proposed two-mile l inear aecelerator, referred t o as Project "M". This report is part of a study of the & n e r d feas ib i l i ty of the s i t e and its threefold purpose is: (1) t o study the geological suftabfli ty of th i s area fo r the project; (2) t o a id the engineers i n est-ting the cost of excavations; and ( 3 ) t o direct attention t o special problems which lllrrhy result %ram geoPogfc conditions at the site.

WCBTION

The area investigated Pfes i n Santa, @lam and S m Mateo counties and has the form of a northwest trending strip, one-half m i l e wfde by three miles long. Junipero &ma Boulevard, t o the west by A3lpfie Road, t o the southwest by the erest of the eas3temmWrange of h i l l s , and t o the east by Fremont Avenue

It is approximately bounded t o the northeast by

The area is on the noPthe@stern slope of low foothi l ls of the California Coast Ranges which border Sm Frmcisco Bay t o the west. This range of" h i l l s fr the mapped m a reaches maximum elevations of aboub 500 f ee t along the rid@ l ine bounding the area t o the southwest. The terrain @;rad- descend8 northeasterly t o the aXluvial plain of the S&n Francisco Bay law1ernd at elevations of 150 t o 200 feet.

Two streams flowing noPtheas;tward t o S a Francisco Bay provide the

Matadem Creek wfth one import- miin drainage. near the western boundary of the m a . ant tr ibutary m&etrs across euz aE?LuviaI pPdn of l o w relief i n the southeastern part of the area. intennittent streams have dissected the range into rounded hillas.

San Frhuaeisqufto Creek flows i n a s t e e p - W e d valley

Between these two m a i n drain&ge-wa;ys,

Soi l cover on the hfUtops and slopes probably averages less than So i l and al_ftnium fi. the upper portions of the gullies one foot .

probably averagr? three or four feet, thickening dawnstretun t o about ten fee t near the break i n slope between the him and the a9Ewial flat.

These h i l l s are generaUy g;pma-cavered wfth a f e w oak trees. Same of the steeper ~ e t v h e s are f i l led wfth brush.

REGIONAL CONS IDIBATIONS

The proposed site of Project "M" l ies in an m a of" faulted and The folded late Mesozoic and T e r t i a r y sediments arad volcanic rocks.

recentv wtfve northwesterly trending Scbn Andreas rift zone lies about three miles t o the southwest of the site. reeenMy active fault zone, p m U e l s the San Andreas approximately 20

The H a y w a r d fault, another

D-2

miles t o the northeast of the site, d t h which no recent movement hm been definitely linked, &o o c e u i n the area.

Mumerow major and minor faults,

It i s apparent t ha t the proposed site is located i n a region of tectonic instabi l i ty . However, it is impossible t o predict when severe earthquakes w ' i l l occur and what effect they WjlS have on the proposed stmcLUpe, The tectonic instabi%ity of the entire Pacific Coast region should be c&m&MLly consfdered in the selection of a site f o r t h i s project *

SOURCES OF GEOLOGIC IWCBRMBTCION

Probably less than one percent 0% the area is outcrop. These

Shales and exposurer%, generally of the more resistant sandstones, Pimes-tones and volcanic rock, occur on top of" rid@$ and i n creek beds. sof t sandstones, which e known t o be present from excavations, rarely outcrop 0

Rocks of %he area, w e exposed i n numerous road cubs and severaJ. Severd excavations no longer accessible have been basalt quarrieso

described by previous writers.

Information fram six holes dril led through the basalt in the southern part of the area was util ized in t h i s r e p ~ r t .

Several earlier reports and descriptive notes uti l ized i n th i s work are l isted in the bibliogrqhy. prepared %y AtchPey and Grose (1954) m e incornorated directly fi t h i s report, *

The m p and several cross-sections

The m p accompanying t h i s report shows exposures of different rock ty-pes by bI.ack-@-white spbo%s. Distribution of variow rock units as interpreted from these observations end from topography is shown by color. The lack of outcrops, cmp8fcated Ycbcal structure and scarcity of continuow m k e s beds, W e the fn teqre ta t ion of the eofogy highly speeu.latfve, especierJ_r;y i n rocks older thean the Los Traneos vsPeanfes. The rock units mapped i n the SemsviUe formation indicate only the genera characteristics of the rocks eenie not the exact poaitfon of hard and sox?% sandstones and shales, SemsvilBe formation ace: (1) relatively hard rocks resistant t o erosion: stone and shde m$y be included; (2) rocks of medium hardness: Cbamfie%rtKly medium hard sandstone, or interbeds of hard sandstone wSth

me units selected f o r mapping i n the

mostly hard, we= consolidated sandstone but some soft sand-

SOB sandstone and. shale; and (3 ) resfstme@ t o erosion:

relatively soft rocks with littXe soft sandstones and/or shales.

Genera

The oldest beds exposed i n the mamapped are sandstones and mudstones of Eocene (and Pdfocene?) age. SemsviLSe formation by Thomas (lglbg) angular discordance are sandstones, volcanic rocks and sandy Ifme- stones assi@ed t o the Miocene Los Trancos formation by Thomas. In topographically low areas, the Searsville formation and the Los Trancos f o m t i o n m e overlapped by unconsolidated gravels, sands and clays of the Plio-Pleistocene Smta Clma formation and by Recent alluvium. These youngest deposits have no direct bewing on Project "M" and therefore they have not been mapped or described.

These are included i n the Overlying these beds with

SearsviEEe Fornation

The SewsviUe f o m t i o n consists of interbedded sandstones, mudstones and shales. accelerator the fomation is about 3000 fee t thick. that the r a t io of sandstone/mudstone is about 4:3. SneraE4ly feldspathic, thick bedded t o massive ewla medium t o coarse grained with a kaolin matrix. cation from relatively loose, friable aund we& t o well-cemented with cwbonate, hence extremely hard and strong. The argillaceous rocks &se cammOnly yellowish buff, massive mudstone, but some grade t o grey- ish and brownish f i s s i l e shales.

In that part of the area traversed by the l inear It is estimated

The sandstones are

They vary in the i r degree of consolid-

Thickness of the interlayers of sand and argillaceous rocks varies from several. tens of feet t o less than one foot. &tho@ definite evidence is lacking, the diff icul ty of correlating bed fo r bed over short distances and the diff icul ty in tracing marker beds fo r any distance along strike indicates that lateral variations i n lithology within the SemsviSPe formation are ecnmnon.

b e Trmcos Formation

The Los Traneos formation c m be conveniently divided into four members frm the base upward. Member A: Member B: canic material; Member C: coarse fragmental sandy limestone; Member D: s o n friable sandstone with rare mudstone layers.

loose t o poorly cemented sand; volcanic rock including basalt ic f l o w and fragmental vol-

Member A ( T U ) overlies the SewsviPPe formation with angular unconformity and underlies the Los Trancos volcanfes. only on Alpine Road and d o n g S a Francisquito Creek where i ts thickness I s estimated at 75 t o 100 feet . It consists dominantly of loose t o weU-cemented medium grained arkosic sand, but may inelude some coarse bioelastic Sfnestone simflar t o Member C. It is not known t o be present east of the veilley of San Francisquito Creek.

It is exposed

D-lb

Member B (TeB) conrsists dmj-nmtly of basal t ic volcanic rocks which vary i n thickness from about 65 fee t on Alpine Road t o a reported 600 feet along Page M i l l Road Atchley md Grose, 195k). ern part of the area, the volcanic rock is dominantly aphanitic olivine basal t vesicular basalt, very strong, hard, and dense where unweathered. flow rocks ( T D B ) form only slightly more than half of the to ta l thickness of volcanic rock. IppeguTarly interlayered with these flows are bands of f rawenta l vofcanics ( T B f ) which have been varioudy described as tuff, breecfa and agglomerate, but much of which appears t o be con&meratico Possibly it was deposited as mud flows and land slides from the flanks of active vo$car&c cones and lava tongues. It consists dominantly of angular t o subrounded frappents of volcanic rock, 1argel.y basalt, which range i n size fram l ess than one inch t o several inches in diameter. been weathered prior t o induration of the rock masi. is not abundant, and although it may be largely altered ash and fine volcanic debris, same fine qua;rtz and feldspathic sand is also present. This fragmental voPcanic rock is structurally weak,and near the surface, at least , is badly weathered.

In the west-

In the basalt quemsPies along Page M i l l Road, these

Many of these f r a o e n t s appear t o have The f ine matrix

Member C (TIC) is probably less than 50 feet thick. It consists of well-cemented coarse she l l framents ("Bmaele Beds"), with interbedded hard eaPcweous sandstone. It is h&.rd and relativePy strong.

An unknown thickness of soft , buff, fine-grained wkosic sandstone with interbedded sof% mudstones and shales directly overlying Member C exposed east of Page Mi%% Road is assigned t o Member D of the Los Trmcos formation (T lD) . but poorly cemented and friable. Traneos formation, it may be Pliocene i n a&?.

The sandstones of" t h i s member are indurated Although assigned t o the Miocene Lo8

STRUCTURE

Beds assigned t o the Eocene SeapsviPle formation @?nerUy strfke The central core northwest and dip 40 t o 70 degrees t o the southwest.

of Eocene rocks is bounded on three sidea by the Miocene Los Trancos formation which dips away from it at about 10 degrees dong the western boundary, and at 30 to k5 degrees dong the southern and eastern bound- aries

Faulting cumplicates t h i s semi-do& structure. A north-south trending fault with upthrown side t o the ewt crosses Juniper0 Serra new the Matdero Creek bridge and results i n the repetition of the Loa Trancos volcanfcs (TU) and overlying beds. fault having i t s upthrown side t o the northeast passes between the two basalt quarries on P a s M i l l Rod but apparently dies out before enter- i n g t h e area of Eocene rocks t o the Norbhwest. A t h i r d f ~ u l t is post- d a t e d passing between San Francisquito Creek and the old basal t quarry and trending northeasterly t o the junction of AEturas Drive and Jmipero Sema Boulevard. This

A northwesterly trending

fault is based on these l ines of

D-5

inconclmivs evidence: (3.) offse t of bands of resistant beds &s expressed by the topography; (2) discordant attitudes of beds of the SeajrsviPSe f o m t i o n near the trace 0% the postulated fault; (3 ) considerable differ- ence i n the general strike of the beds on opposi%e sides of the postulated fault; eend (4) determination of a Paleocene or Ear@ Eocene age f o r foraninifertiL sh&Les outcropping near the entrance t o the S t a n f o r d Go= Course whereas forminiFeraP shales outcropping on Jmipero Serra Boulevard U O O feet southeast of Asturm Drive have been determined as Late Eocene (E De= Milou, P@r60I-d= COIUIIIYGI~CE&~O~) e

In addition t o these three main faults, numerous d E e r faults are doubtlees present wfthin the area. mudstones asld shales show evidence of much shearing and slippage, which however, m y hwe resulted from downhill movement of the rocks or adjust- ments dong bedding planes as a result of folding rather than movement &Lon$ deep-seated faults.

Where wen exposed i n excavations,

ENGINEEJiiING PROPERTIES OF THE ROCKS

Rock bre&sr~. - An attern has been made on the map and sections t o indicate the mount of blasting required fo r excavation. It should be emphasized %hat t h i s is intended t o serve ete; only a roum guide of harhess of the rock units relative t o each other, and experience wil l indicate whether more or less blasting is required.

In construction of the Stanford Tunnel of the Ketch-Hetchy quaduct, the mudstone and s3haLes were mucked out with pneumatic spades and the sendstones were blasted (huenstein, l 9 5 l ) + fe l t t ha t most OF all of the mudstones and shales can be removed d t h o u t blasting in both the open cu% and tunnel. the sofier sandstones of the SearsvfEle formtion can also be removed with shovels, at least in the open cuts. Many of the hecrd sandstones of the SemsviXLe formation WSU require blasting. of the poorly consolidated and fractured fra@ent& volcanic rock (TUf") probably need not be bPmted. w5.U be mostly blasting rock, cdb; w5.l . I the overlying TIC. The soft sandstones and shales of T U should be easily moved with a shovel.

Hence, it is

Probably many of

Much

The solid basalt flm ( T U P )

Tunnel support. - During construction of the Stanford Tunnel of relatively smU diameter (to accommodate 93. inch pipe), continuous i n s t d b t i o n of suppopts at four t o f ive foot centers was required t o combat swelXing and plowage of the shales and mudstones of the SeelssviUe f o m t i o n . S f m l l ~ T y , the poorly consoXidated fra@qnentaP volcani-cs (TDf) and the fractured hvas (TUX) will require at leas t some support during driving of the proposed tunnels.

Slopes of open-cuts. - Assuming adequate drainage, it is considered that permanent %:l sPopeea can be maintained in unweathered rock with the possible exception of the loose framenteil volcanic mterido With the s e exception, most of the other rocks win

D-6

probably stand up fo r a short period of time with a slope as steep as &:lo side s lope, is anticipated where shale beds dip toward rather than away from the excavation.

The greatest diff icul ty in keeping cuts open with these

Lands l ide s

Shearing and % o c a contortions in mudstones and shdes of the SemsviEPe formation indicate that they flow easily. Landslides and slips on hiSbPsides underlain by rocks similar t o the Searsville forma,- t ion fes a, serious problem where the beds dip in the direction of the slope. formation has a dominant southwest dip whereas the slopes are mainly northeasterly. of s l i p p a s dong argiP9aeeous strata.

Fortmately, in the area of the proposed site, the Searsville

Good drainszg is reeonmended t o minimize the dane r

The soia derived fromthe SewsviUe formation is clayey and probably highly p l w t i c when w e t . It is recommended that th i s materia be stripped pr ior t o paabeing f i l l , and t ha t it not be uti l ized as f i l l material.

Groundwater

The writers w e not aware of good aquifers within the Searsville formation, although some of the hard $&stones, if f rmtued, may bear large quantities of water. The Jointed barsalts and fractured fragnental volcanic rocks are known t o be excelC%ent aquifers i n the area and WEU probably be local ly water-bearing where encountered only by the proposed Pine of the accelerator. tions, water control measures were required in hard sandstones overlying the volcanic rocks, but these beds w5U probably not be enemtered i n excavations f o r the accelerator

In the Hetch-Hetchy excava-

Fill Matarid

The L a r g e volume of fill needed near the southeast end of the wce%erator can probably be obtained fran the elongated h i l l about one-haSfY mile due south of the intersection of Page MiLP Road and Japnisro Sema Bo~.~l.evetPd. Although outcrops are lacking, the h i l l is believed t o be composed of s o f t sandstone and shalle of TD. It should be test-driUed before definite plans are made t o use it f o r fin m t e r i d .

The location of adeqmte f i l l . mterid. for the western portion of the project requires further study.

Conclusions

Regarding the geologic sui tabi l i ty of the site, it i s concluded tha t :

Coast region and is about three miles from the recently active San The site is located i n the tectonie&L%y unstable Pacific

D-7

Andreas fault zone. The locatlon of the project pasallel rather than at a high angle t o the trend of the San Andreas zone probably reduces the chance of offsett ing the l ine of the accelerator during a major earthquake

2. Sever& faults cut througb the area of the proposed s i t e . There is no evidence of recent movement dong them.

3. There is no indication that costs of excavation of pock cuts htna tunnels w i l l be excessively hfgb. Rock breakas costs should be ccmpwa.t;ively- lm. are no indications of extrem3.y loose, running ground. of cuts should stand up well.

Tunnel support will doubtless be required but there Side slopes

4. Landslide danger dong the argillaceous beds is minimized by the general dip of the Sewsville beds into the slope.

5 . Groundwater may be a problem locally but no serious flooding of workings is expected.

This paper is t o be regarded as a pre l imfnw report since the availablbe geo2ogic Information is far from adequate for a cmplete study of the site. ing program should be undertaken t o explore the portions of the l ine which are t o be cut or tunnePled and engineering tests made on the materials which wilp be encountered.

Before construction plans are finalized, a d r i l l -

D-8

BIBLIOGRAEE

Atchley, F. W., and Grose, L. T., 1954, Geology of the Page M i l l Quarry area, Stanford, California: unpublished report prepared f o r Utah Construction Coo

Forbes, H., 1951, Geological data and grouting record, Stanford tunnel: unpublished drawing, San Francisco Water Department

Uuenstein, C . A., 1951, F’ressure tunnel links Hetch-Hetchy a,quaduct sections: Western Construction New, v. 26, no. II, p. 85-86.

Pam, B o M., 1947, Geology along the P. G. and E. pipeline, Page M i l l Road and Juniper0 Serra Boulevard: unpublished notes.

Silberling, N. J., and WaMron, J. F., 1951, The geology along the Bay Division Pipeline No. 3: unpublished manuscript, prepared f o r the Cdifornfa Division of Mines.

Thomas, R. G., 1949, Geology of the northwest part of the Palo Alto quadrangle, California: Sciences e

unpublished map, Stanford School of Mineral

D-9

APPENDIX E-1

C O N T R A C T O R * L N O l N L E R 6

UTAH C O N S T R U C T I O N C O M P A N Y O N E H U N D R E D B U S H S T R E E T 0 B A N F R A N C I S C O 4 . C A L I F O R N I A

C A e L I Z A D D R E S S 8 U T A H C O N C O

July 20, 1959

Mr. F. V. L. Pindar W. W. Hansen Laboratories of Physics Stanford University Stanford, California

Dear Sir:

F o r severa l years we have been developing cer ta in information in connection with the proposed construction of the Linear Accelerator. During this period, through discussions and correspondence, we have presented our recommendations on the design and construction of the complete facility. sive studies and analyses accomplished by our company, as well as information available on the proposed s i te prepared by others.

These recommendations, in turn, were based on exten-

While we understand that construction work on the project will be preceded by the normal exploration, geological and related surveys, it is our opinion that the general proposed area will be feasible for construction and presents no abnormal problems in relation to earthquake hazards.

In that connection we have attached a repor t prepared by Mr. Clark E. McHuron, our Consulting Engineering Geologist, who has studied this problem and fur ther expresses our views in this matter.

We appreciate the opportunity to present this information.

Very truly yours, f --

CSD:mf Attach.

C. S. Davis General Vice Pres ident

APPENDIX E-1

CLARK E. McHURON CONSULTING ENGINEERING GEOLOGIST

l S P 8 S O L A N A D R I V E

B L L M 0 N T . C A L I C O R N I A - TELEPHONE LYTELL 1-1oe8

J u l y 20, 1959

Utah Construction Company Cne kiunclred Lush Street San Francisco 4 , Cal i forn ia

Attention: hr. C, S , Davis, General Vice President

Subject : Stanford. Two-hiile Linear Accelerator

Dear Lro Davis:

After ca re fu l ly reviewing the diamond d r i l l core data of t he Ctah Construction Sompany together with the accompanying geologic clata for t he proposed s i t e area f o r t h e Stanford Accelerator immediately South of Stanford. University, walking out t he e n t i r e area on t w o d i f f e r e n t occssions, as wel l as subsequently making an a e r i a l s i t e inspect ion and s tereoscopic exanination of t h e a e r i a l photographs, the wr i t e r makes the followin,: statement:

It is understood t h a t a s u i t a b l e subsurface inves t iya t ion study w i l l be made. Providing the above is s a t i s f a c t o r i l y completed, it is the consic?ered opinion of t h e wr i te r t h a t f i n a l tunnel a l i g m e n t s can be located wi th in the qeneral proposed area which are e n t i r e l y f eas ib l e f o r construct ion and which appear i n a l l reasonable p robab l l i t y t o be within design and oTerationa1 tolerances as regards possible e a r t h movements.

Respectful ly submitted.,

Clark E. N IC P ruron

In dupl ica te C3d: j j

B E C H T E L E N G I N E E R S - C O N S T R U C T O R S

T W O T W E N T Y 6 U S H S T R E E T . . . S A N F R A N C I S C O 4 , C A L I F O R N I A

July 17, 1959

Dr. Edward Ginzton Mi c r ow ave Labor at or y Stanford University Palo Alto, California

Dear Dr. Ginzton:

Enclosed is the report of our Chief Consulting Geologist - Roger Rhoades - concerning the site geology for the proposed Stanford Linear Accelerator.

Mr. Rhoades is a consultant for major hydro-electric and hydraulic studies and engineering with Bechtel Corporation as well as other clients in the United States, Australia, Pakistan, Canada and the South American countries. private practice, Mr. Rhoades was a geologist for the Tennessee Valley Authority and Chief Geologist for the Bureau of Reclamation

Before entering

In transmitting Mr. Rhoades' report , I should like to point out that the Hetch Hetchy Aquaduct, supplying water to San Francisco and other communities in the Bay Area, was recently constructed very close to and generally parallel to the si te of the proposed accelerator.

If there a r e any other questions or problems with which we may be of service, please call on us.

Sincerely, o/li 9 kinson

W D f v s Enclosure

APPENDIX E-2

R O G E R R H O A D E S CONSULTING GEOLOGIST

July 17, 1959

1 0 1 C A L I F O R N I A S T R E E T

SAN FRANClSCO I I .CALIFORNIA

TELEPHONE. DOUGLAS 2-4032

C A B L E A R O D E S

Mr. B. W. 0. Dickinson Bechtel Corporation 220 Bush Street San Francisco, California

Dear Mr . Dickinson:

I have again reviewed the available geologic data, maps, c r o s s sections, and report relevant to the seismic potential of the a r e a in which it i s proposed to e rec t the Stanford accelerator.

A tunnel o r equivalent cut-and-cgver system some two mi les in length is proposed. This line is crossed by two faults and possibly by a third. There may also be other zones of shear o r fault-like displacements of smaller magnitude which cannot be discerned on the ground surface. These are a l l old faults vithout any evidence of movement in the historic t imes. to be inactive faults, and that the chances of their resuming activity a r e negligible. For this reason, I can foresee no danger that the s t ructure would be physically broken o r offset, o r i t s alignment distorted.

I consider them

The San Andreas fault zone l ies a few mi les to the west. Stanford University has experienced earthquake vibrations emanating f rom this fault zone, notably in 1906. experience similar effects from time to time but probably not frequently.

The accelerator installation in question would probably

I wish to make it c lear that I am talking of two different things. First, the faults which actually c r o s s the line of the proposed tunnel o r cut- and-cover s t ructure are old and inactive, and would not, in m y opinion, jeopardize the structure. Second, a known active fault l i es a few mi le s to the west of this a rea , and from it there will emanate earthquake effects in the future as in the past.

Naturally, the design and construction of the s t ructure would incorporate the usual features for earthquake resistance; but this is standard engineering practice in regions where earthquakes a r e expectable.

Sincerely your

Roger Rhoade s Consulting Geologist

RR:dk

APPENDIX E - 3

K A I S E R E N G I N E E R S DIVISION OF H E N R Y J K A I S E R COMPANY

K A I S E R B U I L D I N G * O A K L A N D 12, C A L I F O R N I A

July 16, 1959

Dr. F. V. L. Pindar Associate Director Hansen Laboratories of Physics Stanford University Palo Alto, California

Dear a. Pindax:

In reply to your inquiry with respect t o the feasibi l i ty of tunneling in the proposed location for the Stanford Linear Accelerator, the fo l lo t ihg i s the comment of our geobgist, Mr. D. J. Frost.

Based upon a f i e ld reconnaissance of the proposed s i t e and adjacent area, it is his opinion that:

1. The proposed tunnels w i l l pass through and be constructed i n rocks which dl1 afford better general tunnel driving conditions than are average for the general Central Coast Range area of California.

2. The two minor fault fracbme areas which cross the tunnel s i t e are thrust type, are of probable Pleistocene age, and are now inactive. Andreas System complex, no significant movement i s expected along these fracture zones.

Since they are unrelated to the San

3 . Sarring general catastrophic wide spread West Coast earth movements, the long range physical s tab i l i ty of the constructed tunnels would be expected.

These opinions are based on an insgection of the surface, and on general knowledge and experience i n t h i s area. program of investigation of the proposed si te by core dr i l l ing be undertaken.

We recommend, of course, that a

Very truly yours,

KAISER EXGDEEFE Division of Henry J. Kaiser Company

DFS: hs

David F. Shaw Vice President

KNS@ \\- _ZNQIN.€ERS

E N G I N E E R I N G - C O N S T R U C T l O N C O N T R A C T I N G S I N C E 1 9 1 4

APPENDIX F

SELECTED REFERENCES

The following references were extensively consulted duringthe preparation of t h i s report. a complete bibliography is being campi1ed. l i s ted w e those which m e most pertinent t o the present investigr3tion.

Many other sowces have been examined, and Howver, publications

1.

2.

30

4.

50

6 0

7.

8..

9 .

Branner, J. G.; Newsme, J. F.; Arnold, R e Geology of the Santa,

C m Qur3dran6fPE?, California. Folio 163, Uo S. Geol. Survey (1909).

ByerBy, Perry. Seismology. Pmntice Hdl, New York (1942).

Freeman, J. R . Earthquake Dlsmaae and Earthquake Insurance. McGraw H i l l , New York (1932) earthquake effects )

Gilbert, Go K. e t &Lo

April 18, 1906.

Gutenberg, B. and Richter, C. F. Seismicity of the Earth. Princeton University Press, Princeton, N. J.

Jenkins, 0. P ,

B U e 15k, Cd i fomia Division of Mines (1951) of regional geology and an arbicle by D r . Byerly on the earthquake history of the area. )

m i n e , D. I). and Jufdd, W, R.

McGraw H i l l , New York (1957) .,

Lawson, A. C., ed. Pub. 87, Volb. 1, Cmegfe lnstiturte, Washington, D. C. (1908). (Exhaustive description of eehquake effects i n the San Francisco Area. )

(An exbensive compilation of data on

Seul F r ~ c i s c o Earthquake and Fire of" Bu31E. 324, U. S. Geol. S m e y (1907).

Revo Ed. (1954).

Geologic Guidebook of" the San Francisco Bay Counties. (Contains a review

Prficiples of Engineerfig Geology.

The California Earthquake of April 18, 1906.

Manning, John. Groundwater and HydlpoPogy of the Pdo Alto Foothills. Unpublished pepor%, City of Palo AEto Water Dept (3.959).

F-%

Oakshott, G* Be, ed Earthquakes in Kern County, California

during: 1952. B u l l . In, California Division of Mines (1955) e

(A comprehensive modern account of a major earthquake.)

R e i d , H. F.

Mechanics of the Earthquake. Washington, D. C (1910) e

rebound theory" . )

The California Earthquake of April 18, 1906; the Pub. 87, Vol. 2, Carnegie Inst i tute ,

(The original statement of the "elastic

Richter, C. F. Elementary Seismology. Freeman Co., San Francisco

(1958). (The most up-to-date textbook on thisl subject e )

Ternsaghi, Karl. Geology in Relation t o Tunnelinq. Chap. 1-5 in: F'roctor and White; Rock Tunneling with Steel Supports; Commercial Shearing and Stamping Co

Thomas, R . G.

California.

YounGtown, Ohio (1946).

Geology of the Northwest Palo Alto Quadrangle, Unpublished map, Stanford University (1949).

Whitten, C . A.

Vole 37, T r a n s

C r u s t a l Movements i n California and Nevada. Americw Geophysical Union (1956).

Whitten, C . A. Horizonttal Earth Movements i n California. U. S. Coast and Geodetic Survey (April 1949).

Jour.

W i p l i s , Bailey. Earthquake Ri5k i n CaPffornia. S t d o r d Univ.

(1925). BuUetin of the Seismological Societies of America.)

(A series of artic9es o r i g i w published In the

- - - - - - - - Santa Clara Valley Investigation. Bull. 7, Calfformfa State Water Resources Boaxd (1955)

F-2

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