'~® M.' ·ABIG~IL STEEL.

~ ~~TJ:ON

^OF-

SPiu.~':'IClr

^{AND A}

sEiz~o~ ~F

^ITS

CONSnToTIVE PROPERnES WITH COMPARISONS'l'OICE ANDSNOW.:.~ '::-.'

"

.~. "

'Ne wf ound land

'~® M.' ·ABIG~IL STEEL.

^{B.SC .(ENG)}

!"arch,..1989

A

th e s is-sub.ii h dto

'the

school.of Gradu a te..

.st udi es"in

~art'i:i'fU-¥.illlD~nt

^et:

~e

requirements forthe"deqreeof.

/ ''-. .-

. .

M'.~.ro

^of

E~!n. -. .; .

Facur tyot Engine e r ing andAPp.l !!.~~~e Me~or1alUniv e r s i ty ot NeWfo~ndland

,

^,

:~.>~

.

.-.~".

' ...:

,::>.

.

~'

..

....s:

I ..

L'auleUf IIaccordeunalicence-Irrevocableat non excruslveperinettiml8la'B1bllolMque na-

1.lonaIedu Canadadere:Pl'odUiie;prAter;,,dlS-'" .

· =:~:~~;~:d:U~~:I:nt:~:~.~:..:\:

JSBN.0- 31S-5 0 4? O- 6

· ^.

\

"u

,"::

SO~id

-

~~e,g=a:riU:fa'~

'ic e; andlano....

' an~

.a',brief'. presaurellleter,,the ex~e_~~~en~~l .r~,su).ta' 'are

:I::: ::a:w~::v~rp:~:~:::'~m.:: tut~ .w~r.

wa s evaluated'thr ough', 'a"large-scale

~~to~ s.i~ulation:

^'F'.

l~,"~~_._:~~",·i.'·"'-'S>t~~r:1.,W::l;j;esI'''-c'-:'''':-''-'-',fi

we~eperfonned on 'the laboratorY

This th~sis^{.exami ne s}"~e prod~~tion ^of th~. spray- ice~ and·s eve r al of -....u•.,const itutivepropertl~9with

comparis~ns

^{drawn to}

~xisting spraY:"lc~ dat~

^{. ,}

~w~'~l ~s·

^>

~ S:hOW,

_.

ice-~ ~nd

_' ^soil. Consideration'

' . w~~ giv~n

^{.' as}

t~ 'h~W

^'.

.

spray-icewas best 're pr e s e nt ed'

as

an engineering'mater!al arid what factors ef f ec t it s behavior.

I~ W~$' al~~ : iJport~nt

~eview

^{theme thods'}

·~i·-

producti9n..

'" ' ,

From these,,eXperi~ents it was found that spi"a~-ice,

\ ..J 'behaved

,i~ ~ ~arm'er simi1~'r to"granUl~:t:_ i~e

^or

. l~ose'

^{sa nd."}

;...,H?WeVe~~ ,,it s failure'.anveLc pe-has a·Sh~e thatagrees with solid,.ic~'' ^or\ ^snow.,"~h~, ,'.COh'es.ive^-'.,'propert;!es- - ..",-,Of'"sp~ay-ic~

' .

^.

Pl~:SanimRortantrQ~i.n.d.E§term.ini~gits.'~~~~iour~It,wa s found that.spray-.is¢'st r e nqth.and:fa il)1r e typ e,was

":,.depenaent o~ the con:f!ninq,''pr es s ur e 'a ndc'onsolidat1'o~'

~... . " , - . , •. " ..$ .

. a,s'we'll .being"af f ec t ed ~)',the.,~est temperat.ur~~

r..

i,

"

J

/ ,"'~

,..

/.

.",

. ^. :

^..,:...

.

^{/ :} .~

. ^;'

rate and sampledensity. The strenqth foundinthi s study do not

e~·t i.rtiy

agree 6 ti t h the

resu1t~

^of

'o~e~s

^on'

~pra:Y-ice.

^but'

~.;

^strenqtli

valU~

^and stress-straincur:.es ere sWler. The'b.heviour_i.

_r

we.'

_- ~o.~ _...

ⁱⁿ

_... so.e~~se·s _.. t :

that of' solid,.qran.u~ar·ice·a nd/s,:ow•.The press?remetar te ats'perfoned·on"sprily-ice di d not'c omp a r e well with

~al~~{

^·in.

^tn. l1t~~a~ure

^{but, in general, aqreed.,}lth'}

th~

derived:'

tri~Xial . res~lts~.

,Ge n e r a lly , .

thes~

^{te s t s}

. wer~·

^/,

~;

ettectiv8 ,1n eVal~atin9' spra~- ice but additional work is re'quired'-eei 'und ers t and this' in~erestinq ^and importan~

/

. ' .

.material .. ,.I.

-

,/

I'W~uld like to offer my.~ incere Morin And Dr}.Jack Clark f~r their without Which'this "iiork

w~uld

^{not have}

r~a~hEld

amalso";nde bt e d,'t o'my.supElrvis?rs~ 'Memori~ li'ni[v. ·••

,.v:

...C-'COREfortheir,~en~rous'fundinq'providedforth iS

\. I w6u~d^like~o'^thapk~y',huSba~d.

endihqsupp~~'a ndencouraqem~ntthouqJ;0u't this 'I..".,':

Finally/.1:dedicate th)swork tomy father;,John

who/pas~~a ~way ~,~ .O~~ffa .

^'

/

.)

.

^'

,.2

14.

11:4

102

II

1O~

~" " """ '\::":''';''''T'''':' 'C\:< " ,''t'" , :"

^{s, ,",'"}

.~"'"

^{'," ,';}<\ "" ',

~:' "' ''''' ~

^;"'""

rv,

~

^,/

l~ary spray~Ica EXP.rim.nt : ";\]11 / -;:;'~\

IV. lo', 40JllPa_r~~~!.1..or_~esults/ "

.IV.'2FieldProduction of,Spray-rce 1V~2.1"i nt r oduc tion " . IV. 2;2~tojectoutlinean~ Equipment~ IV.2~3ReSUlts and Observations '

. II,

IV.3 Method of,.,MakingLaboratory Spray-Ice .IV -.3.1,~n~roduct~onand, Equip,mant·

i~:; :;· ~~~~i;;C~~~~~:~:~~: P'r~duction

_{j \ . -/}

IV.4·Triaxicll Tests on spray-Ice' • XV.4•1/Introduction,and Purpose

'I V •.4.2 prepp.ratlon.o tTest speci1llens .

" IV. 4.3 Te s t p~ocedureand Equipment . .

IV.4.4 Triaxial,Te s t Result.-a nd tnterpr,etation

'. ' I \ . : , :

IV.S i~~~~l~~i~~~~~l~nIce .fore: and.Sa~p;Les

IV"

~I ~hi~ .sec~ion

^{Result:: "}

V DIS~.s'SION.OF""RE~ULTS"".: ..,"-' 151

V,l

Intr;,duc,ion \ ' . :,: ~51

V.:!

'~~~r~tory

^{andFi e l d'}productlo':a"of

'sp"r~~jc~ _ _

;1.52, )

. V.3

pressJreme~er T~~t \~esults

^..

~.

^{'- , ;'" ..'' . . 1S'l}

.V' ~'ll:tntrodUCtiOn \ . ,/

• V.3.2Comparison with Resolute and'Ll MEXResults , V.3.3Icomparison'wi th,Soils ' .",1' . . ..

\ "V.3.4i~omp~rison,with\'IceandSp;:ay-I

7

^,e•

V.4.:

~~~~It~i~~~~c~~~~~

^ts\

V.4.2 Comp,arison'with Soils . ~ V.4.Ucomparis.onWit.h..SOlid, G.ranularrceand~now'

.,V.4:.!Comparison.withsp~.aY-Ic\ .

v.s 'Ob s e ations and Fut ure"Work .... 1S1 \

VI!".:

CON~LJSIONS

^.

~S: . .,.;:~~

j::~::E: I

^{J : : : ...•••}

_~

jpP~NOIX

^{B ) 209 _',I}

.'<...• ••

! : ' J, , _: i";"'~~.~"" ,.,; ^{.. 6 : . 1 ." ;} i

18 18

21 23 2S 28 ,29 36

3.

3.

./),

41

42

43

43

47

48

-

4.

52

vii

Ic e island density and s~linityprofile Simpl~tied str~ss-strain;cU,rve

'IceeIu8lity tests on spray and flooded ice

.C_onstructionSchedUle

I .

I :

F~ilure m,~desof.gr~Undrd.lC~,i~land,s"

~~~rlmenta~ 'set-u~fori.fracturt toughnes~

.'.

'~~eep

^curve'for a constant

~ess

^test

~n

:ice "'_'_" .. - _' ..

Str~ss/straincurvefor a constant strain test'(moderate rate)

'stress/strai~curves for'snow ice 'and iceberg'

ice at differentlit r ai nrate~'y' Str.atrrrate -dependence for strength forTl, granular encv ice

. " ,I ,

stress""strain curves for ploycrystalline ice forva r i ous confiningpres-sures

: . ,_ I _? -v'

kaxium stress VS. confining pressure at differ_~ntstrain rates .- Mohr C;'9.10mb,~nJelOl'etor broken ice' oedometer. ,test-cn.eecken ice T~iaxialcompres sionte s t

on

broken ice Ram hardness vs , age'for processed snow

2.1.1 Loc,-pon of Arctic Activities

2~2 spray-iceFormation 2.1. 3 •Typical's p r a y - i c e'eere pt'ptile 2.1.4

Typi~al ~raY-ic~

^core

pr~fil~

2.2.1 2.1.8 2.1.6 ,) 2.1.7

2."1.9 . 2.1.5

2.2.4

2.2 .5

2.2.6

2.2.9 2.2.8'

2.2.10 2.2 .11.

2.2.15 Torslonalshea r VB: density

2.'J.1 The.Roc t es t pres s ureDeter

7' ••

••

57" "_

.2 .7

100

10 5. 10.

10 9·

112 11.

11.

12.

12.

12.

12 7

12 . / :95

viii. Triaxialtest arrangement corre,ctedpresB~remetar; cu..:"~·

Relaxation test.ontr e s h water ice cylinder Pa t hot"CSS(Ba l tindur i n; Ll KEX • Exampleot LIMEXcor r ec tedpressuremet er curve-

Locat.ic:notRe s ol u -eeexp~riment

.4 hour consolidationphase,

pressur~

19hourc~nsolidationpha;ie. atvarious~ll

pressu res ~

Stres s-gtrain.curve s at thre llcellpre ssures'-- (4hourconsoli~ation)

4.2.1 2."3.2

-,

2. 3.3

4.l,..3 .4.1.2

..

,..

4

:1.

⁴ ,~~~~;e~^{ot Re s olute}co.r~~ct8d~r'ess~re'Jlleter^.:' .. ..1.5 ,.

Exa~le'

^{ot'calga ry}

~;~aY-i'~e ~orre~~ed '

^...

pressu reme te r curve . -, .

s/raY- ic8 te st sita ,

Turn~r~ ~~l ley,

^ALT

./

.

^{. "}

, 4.2.2 /spraY~ iO\t~rm~tion ,.Turner ~~ ile~ ,.^AL'T•

4. 3:1 spray-icenozzle contigur a tion ".

. . 4.3.2

_I

1

Grain size

ana~ysi"s

_. ^{on spray-lee}_{. ..}

4.4.1 Tri ax,ial sample'prepa ratil,n 4.4.I2

4.4 .3I at variou&'f'cel l

,·;·:/·

^.

· · · :: : .~--.="

⁽¹⁹hour oonso lida t io n)cu ev•• " - -,

~"

^resauz-es

t:":~.

....

4.7 s~ress-,:st"raincurves, attvo st rain rates

'. " " /

: - '.

4~4,.16 •strenqt11 ve:z:sus consolidation ti me (172kP~) 4".4.17 stren~J:lvaeeusc'ell~essure ⁽⁴ hour

i consolidation) ~

4.4 .1 9

·s/t~ng.th· v~rsus_cell

^{pressure'(:1.9hour}

,, ' lCO~SOl~da.t.iPn.~. .

4.4.19~· stress-path r,ep res e nt at i am of complete , . test hi;atory.'.4hour ,co,nsolidation)_ . 4.4.20 Stress-pathrepre s entat i ~nof complete

te s t:ht s t ory (19hourconsolidatiC!n~

4.4.21 stress-path repre s e nt a t i o n, test s~renqth values (4 hou rconsolidation)

I .

4.4.22 Stress':"pathrepresentation, te s t.strength va~ues (:9hour ...conso lidation)\- , 4..4. 2 3 Mohrcircle represontation,te s't strength

values (4 hour consolidation) ,__~--_..

4.4.9

4.4.10

4.4 .11

4.4.12. 4.4.13.

4. 4 . 14 4.4.15

4.4.24

stress-stt'~incurves, at two test temperatures st~ess-straj:ncurves,

at

tw~consoll-idation times'fcell pressureA4 ~kPa)

.Stre~s:strain'c u rves'"at,..,~wo cons~olidation

tiJtl~S(cellpr~ssure86 kPa).

Stress-strain cu rves, at't wo consolidation ti me s ..ecell pressur e17 2kPa) . strengthver~ustempe r a t u r e Strength versusstraiJ.'l rate

Strengthversus con~~lidationtime (45kPa) st r e n gt h versus consolidationtime (86-~pa)

Mohr'-circle

represe~tation,

^{te s t}

stren~h

values(19hour.cons oli da t i on ) ), 129 13.

131

132

135 135 136 136 137 137

138

041;

139

139

141

142

14 3

143

;)r, ',

,.

4.1.1 'Summary of LlMEXpr~ssuumQtertes t ;esults 88 2.3.1 suinmary·ofhi gh-speed pree eureaeeez-test results. 74 .2.3.2,Short-termpreesureaeeertes t,r esu l t s in"i c e ·76 78 24 24

89

.1~

120, /. '

122'

14Q·, i4<4

~54' 171 175 /"

I

Long-termc're ep parametersfrompressureme t e r

testsonice ", ' .

sp ra y-ic e properties

Comparison ofpre s s ure meterresults

~t'ilt'Xial ~nd'(uniaxial

^"test

r~sults

salinityprofile (c ore'9 )'.

s~afy

of

'Res'~lute pres~u:remeter

resul; s 's"umm'ary

o ' t ca~~ary

^spray-lce

'pressuremet~ ~est

~~~ ^'

. .

, ' . '~ ,

2.3.3

2.1.2 spray-ie.eproperties I 2.1.i S,pr~y-leeprop e.rties'1,1

'(

.

4.1.3 a.1.4

4. 4 . 4

5.4.2'Acompa riso n oft~ston spray-i~e

·~Q TrTU ' .

,4.3.;~ SpraY-ie~nozzI..~"di mens i ons"

4.4 ;1 Tabl.e Of.:t.~i.~d.~~..test_~5!"p:t'ogram...: '.4.4 .~;2. Tableof triaxial test initial re'sults

4.4.3. Summa~of.faH~rscriter.ion ,;-s sui t s

I INTBQmlCTION

With

the

advancementot ice technology in North America in the past decade and the increasinq-c o s t s of"const~ct i..on

"'" . iri

the~rc~ic,'manyoil producers,are lOOking at:'~heuseot'

"spray-lee a.sa 'vi abl e <ionstructionmaterial. Spray-iceisa -.".;

fine granular material formed throuqh the high pressure spraying of water\i~t~acol~oenvironme nt..

As spr~y:," ice is a relatively new material onl y a lilDited

amo~nt'

'Of tests'beve been-completedto

determin~

it s

ba~ic ;~s~r~ngth ·Characterist·ic~.~

^{In order to}

~~

^{able to}

increase its ~~~uction ,while main'ta,ininq e",c o mpe t e nt

: ma:t~rial

^,'.add i t i o nal research work was

thoug~t ~ece~sary

^•.

'!7h~

objectiyes"

of~ 'th~

"

fOllo~ing ~~po1

are:' (1) ee he,lp' understand·what affects spray-ice_bej.'-avi6~randto-cons ~dBr .how it~s-~~eat r.epr~sented.a s an engineering materlal ; (2) to.'add to.th&eXistin9"ctat.abase'o f s~rengt:h information on spray-feewhile asses s -ing-a mea':!s~:O f.performing Ins ituand' laboratory tests on.'the' ice end".(3) to evaluate the

"produc;::~ton ~f~pray- tcein thelaboratoryas weU as .through a rul:l-scel.eexperiml:'nt.

~npreparl,n,gthe test program..it was important.that the res~ltscoUld";b~correlated top~e:-'ioUSlYattain'edfi~ldand laboratory'data, while provtding the greatest\amount ot i.n~ormationpossible. It was 'therefore de'cidedto look at epray-dce ,U~der of}.eld andv •laboratory conditiona. The pressuremeterwas's.el ectEid~o^{eve fue ees}p ra y- i ce insitu and'

.;

t riaxial te~t8 ,were employed to'test spray-I ce.

To

a~01llP118h'

^the'above

d~cr1bed

^objectives

~e

^work

will proc:':eed according to'the.to11 O\11' lng schedule;. (1 ) A l it erature review,I s pr e senua-on spray-ice , oth~r_typersot. ice and the'pre~8urellleter, (2)'the sp r a y - i ce

is

assessed in detail wIth conBid~rat lon given to the material , "its forma t i o nand,.i tsuses ; (3) the strengthpropertiesot'soHd ice, granular Ice an d snow"a r e ,s umma r i ied and finally (4)

the.p ; e s s ureme ter equ i pment .i s.

de8cri~ed

^lh'

~etail

^along

- /. . ,;'

.

wi t h the testin:e rpr e t a t ion and itsapP~lcationtoIc e•. In

~be·. experi~~~~al

·s e c tio n·

the~

^t'ieid'

81)9.:

laboratory.

te~.ts are coniilde~ed, the;~roductlon of bpray-lce' is as sess e d and the i,?8crystallography.isexamI n ed . ,A~.e~ieB· \ of field

p " ;: e•• u~e1Deter tes "ts

9" spray-ice·

a"~ · o~her

^:

•.7 first-y ea r·ic e is·

p~esent~.· "

^The

pr~uc:.tion o~·

BP; ay-ic eis. evalua ted through'. con sidering a lar qe -scale exper i ment performe dby ERc.L(£ S8 0Research~~<;o.··Lter.) a~by lOOki~at"

~ thelabOr atoryprod:uctJ,on of spray-ice.· Triaxial.te,tahave

;be en

~ormed

^ort

~aborato~

^{iliad. spray-ice-e nd the. ice":-}

cry s talloqrAph y was'de:e~ined·fo~samples trom the't(eld.~

well as sampl esp~epar~d inthe laboratoryand subjected·to,

.triaxial tests·. . . \ •

In' the.dis'cussion of the

I

re sults

th~ success

^{o'f·the,·, '}

spray~lce pr~uction~ experim~nts

^{·isas sesse d}

alo~g

^with\l'he

in&ita and lab?~atory tests.. Also, the findings from the. I "."

field and IAl5orAtory tests are compared with results fr om

,

-

the l i teratur, o~ soi l , soli~ ice, gr~nUla~iC8:snow ,and spray -1Ce-"tiElr e thedata are ava i.~ able. Thes e compa r ison s

~ssi s t in: providing j.nform a tio~, on the behavior of spr a y-i c e•

. .• • ... .. :: ~ ,

.>

.>.

~.

,I;r. pTERATYRE'Rt yU;W, r,

II.1~

II.1.1 Int r od uc t ionI'

Fromthe'c o nstructi on all;ea~ycompleted',in'the Arcti c,

it' seems that sp ray-ice islands ~CO~ld :cu t ...~XPIoratiOn.' drilli~g C;;:osts'by a~ leas t' tifty percent in'sha llOW';to jOdera~ewate r depths (w1"!.¥ams , ~9 851Juvkam-Wold, 19~~);' .: Rec enth , spray-ice haa also been1:1S~d inthe constructio,n.

o~ barriers around ottshore structure s and.t1o~ti'neJ ic~~

, ' , j

islanda. Tha apray-ice,~arri.r protacta·a _trueturaf rc,,),...

the tor c e s otthea'rct icde e~heetand.cr8ates'a~ ~ce_rubble moundtha t in,itselt'dete n ds

the

.tructur~^•. ~pr~y,:,icB._has ^' been

emPl.~fed

^to

~'~iticial.l~ ~.ic~e .

^{n.. , ice}

sh~et'

^{-.i.n',th.e.:',.. '}

, dee p wate r s ot the highArctic and.i t hasbeenuse'din'the, .

<,

)'const~ctibn

^{at a}

gro~ed 'isla~' i~'

^the.

BeaU:to~:

^{see .}

(Masters~~

^et

.~l ' 1.986(b~

^I.'

~o;i :~ " :

,1.9 8 7 ):

'.,Th:~ '~~~~al

^'.

loc a tio n of ~e ^Arctic exp,lorati on activities is ShO~ⁱⁿ the lIlap on Fi gure 2.1. 1.

Spra y-ice is l ands.ae e no't-onl y ec on omi ca l'in term s ot. the act u a l-island'c ons truc t ion , but there isal s ,? a.s avi~.g

d~e^{totheshort er}c~nstruction^{perlod, A spr ay-ice}i,sl~nd requires. 30 tei 45 days const~ct~on' time'while'a grav,,:(,- island needs 60'to 90'da y s

(Wllli~ma,

^{198 5),}

I~

^{mddi tTo),}

f~r. grav el island constructio n·there is a n~ed" f~r

.

'.

.

':'~.--...

" -

",'

'c 6 ns t ru c tion permits , dredging and,transporti.p9...Qravel..:a~'

well as havingthe'drillrig ready

W~ll'

ⁱⁿ

advance" becau~ef

_{r \}

'''''

_.

I" "

'.

\

'r:

" .

19 7 8- 7 9 .

.-.Fi gure2.1".1

Location ofArc~ic,ExplorationActivt'ties E?CAl'fPf:.ESOFSPRAY- :tCE CONSTRUcrIO N 1 Mars; ,AIIloco,.~~ S 6 .I_ c, 2Ice IslandExperim e nt , Jo i nt Venture . 3Exp e rimenta l llti a nd, Exxon', 19 78-79 . 4 IS SUi'lg n'ak , Es s o, 199 0.

5Alerk~'ESSO, 198 2.

6 Anqaflak L-03. Esso~Exxon,1986-87.

7Cape Allison C- 47 ,·Panar c ti c, 1984 - 8 5.

8co rnwall , 1985-8 6. .

'9Buckin~ham_0.68 , 19 8 5- 8 6.

/, :-

'/

of the neces sari l y'br ief

'~-'-_, ' ,',:, " , ','J envir~lnmental poipt ofvi ~w,th!!Spr~!-ice i'slafid"als o ha,~"

the advantage that , once thedrilliri g: .is'c otlple t edin,'t he springor summer, the1slan~wi ll,melt:'\ 'l'hls,me ansthe re willbe~ewor no ionq'te~'eff e cts,onthesu;r~undin? are~.

,The purp oseof this sectionis to reviewthe cur rent litel~ture'onspray- i ce. spray-icewill 'firstbedescribed a. •.aterk, and .".pI es of

ho~

^ithas'bee n used.in construction'will be illustrated~ The physical

ana Illechani~al lproperties ^{w+: ,1 ,}

^e.,S,""",'arlzed froin,'existing field and labdratory t s'a,s foun d'in the_'literature'~

/ ', ,

Cesign aspects ,t or spray-ice,constructi~n,Willbep~min~.' Theadvantag~an4'd i s!ldy a ntag8 s of's p,ray- ice,'will,then,:',be "- 'reviewed and conside"ratio n,'gi ve n to the fut ure.of sp ray-

lee.

II. l.2 Spray-IceProductio n\

t e

^{has been'}

us'e~

^{as a structu ral}material for many yea rsinth~.Arctic". The·lIHitai-ydeveloped its use in the ,: 950'.ef o,rJh e

"pst~ction ~f~~ads. brid9". jn~ ~nw.y"

^;/.

(Duthweiller et ai, 1985 ). Morl recllnt l y ,

f~oatin9 ',iclI

'l !11 ands have

bee~'/ con~tructed .

^for 8Xplorato& :drilling puiposes bY"

f1o~ing:

^sheet,ice

~ith

^{water to/b Uild'up a'}

frozen aaes

(~~sterso~

^{et et,}

~98,6.(an . The "mi~r ~,r6b~~S

... assoc.l,ated'withflooding'an ice sheet wer,e thellotibuild-up.

t, .. - " -

^Lee

~.

" " : - - '

' L ' :-"'C _~--~ .:

t> : ; ;:/ - 7 • / ~L . .

^<2

1/ l~., ,~^...,,~... . ',~ J,~, {~'.~~z.~,,,,,,, ~J^...I>-..\ 1,,.;....: ~ti~l>."t:~'tJ *'.ii~\t""-:I.

impo s e d mont hs.' and \he dep endency of 's tren g t h th.e

con d ition s duri n gcons truc tion.

discov ;ry of

spr~''':~~el

^{.as i t app lies to the}

"",/' o"atOry ddl~lngoperation, has 7"ene wedthe use...of, ice ,i\

stryct~ral : "ma~erial.

^{spray- fJe .}

h~g signi~l~-~ntly

• / ' : r ' :.

:h igher buiicl7'up rate s-th anflo oded~cer,:with"ratesof-up to '60":' / day

ha~g bee~'

achi!"ve d

i~

^the

exp~rimental isla~d

con struct ed by.scnae an d Par.tne rs in 19 85 (Go !! e t al , / 19 86)..· _

-"·..Spray";'!ce-!s f ormed bY.highp,ressure spt:ay1nQOf salt

wa t ;

t.l!roU~h

^tha

OOl~ -A'rct;~

^{.aiF.' Laten t heat}

:'i~'

^.

rapid~y

^,

tr.ansm,i.~ted ~o : the_' llii

^.from"

the ' travellin~"water

drOP let,s-1'

cr,e'~~~ng

^__ice

c~t;;li.s

^beforethe'dro plets."

r~aC:h .

^the:

qr~~d ~\

'.Th (,.

m~t~r~~l'

_,--,

...

^{' .}

consist~'n,cir

^{.', "}

de~ElndS '

^on

,th~

^_

~ir ~emper~

^1;ure,\'

~.ein i. tial,":rlOW::~ate^{an d} Pte~," "di.stanc e " t ra vel , .:

,a nd the..sali~ity·of the.wa~er ; ^LOnc e,on the grou ":d,'it' va rie s,from'~ "snow '" of ice cxystals, to a ~flu ffys1eet",.•

toasoft;slush. ~ . . .... , . ,

From observa t ions on'tes t and exPl oratory spray-ice

. .' , /

~zjlandB ,. o~timumc;:.on~itions_~for ,akin g.la ~e ~antities

of

sp ray- ice

.

in .ll sho rt^"ti me'"span'ha ve^. be en ascertained.^{'.'" '}

^.

.

Ge n.

e~~.l~Y

^{.•·the 1.ow.er .th.e.}

t~p~er~tu:~e"j

^{.th.8.high er..}

1 .

^{e .}

~~

content of -E:he spra y- i ce. Air te mp e r atures .shOUld, at

le~~t

^{...,J.5deg re es Cand·}

~refe~ablY ~20

^to'

~tl0 ~e;i

^s.C•.

The8P~~Y lO~;zle l s g'et a:t'an

, .

,ii,.nql.6 'o f be twe en 4; and 60

estilll';'ted volWlledue to-·br i ne·drainage

:and

vind·d.is~ision

(~, ,198~). ~

^.

R

_:In order,t o producethe very larqe.vOl.u:'esof spr!Y-,lc:e nece s s a ry f~rislande~~n.truction . usu.i~ytwo to'four -pumps ope"ra te,s iJDult.neo~SlY to co v er thear e a'o f the.ice pa~."

The Pumfls-...are hoo~ed upt~a'~oveable ,s ki d or st'ationary

.: .v-, I ,.. '

swivel ,~rrang~m.en~

f a

.Wh~,ch. a~'f i r e nOZZI.e.l s,conMcte~. T_~e set,u p

is:

^'siJiila r t o.that.~h~wnin,Fl <JUre 2. 1.2.",The.pumps typical,lYoperate at a capacl~.y'of be t we en 1.50Q:and18000

..-'f l/m!n-,

~~.

^800'to

' 15~~ kPa~ depen(unq C?~.

^the'

tn,,'

'arid

'~~e~~ :

Duri!:'-g the

'c:onstructi~n 'o~; .~e

^:

~IDS. -,(~~~c~ete ·Isl~~,

^.

.,0;il l1ng'

- s)"stell ' o~ed ,by GI~baL·.·'Madne·)\ spra;~ice

the pumps:"'Were .

s~tion~

^on'

~~d

^{:an ,.,}

----.-~~ --'_.-. ~ ~ - '-~--.--~-_._--- - '~ -~._----"!

allowed for .gr eater lDobil1ty,and larger-

; de9ree"•.

t~. ~

^{" '}

between 60'and'90.e t r e sand;'~dea:llY, no'vlnd.~

11.'1.3Free'zingand'Sint e r!:ng'Proce s sesof

Sp~aY-Ici'e ~

, Abetter'

u~derstandinq

^of

spra"-ic~';~~n 'be

at t a i ned':,hy' "

reviewinq -1 n

lIlo~e ~et~~l\a

^{few'aspects"Of'its}

: f6~a~i~n'"

inclu d ing th e tonatien'ef 'the ice granule.s'a~d their' sin~eri~g.

:In the re port by Zarling (1980) the heat and.mas s"

transfe,r/fro~

^tt!:'Q

w~ter

^:'oPle'tsis'

e~~mi~~ .,~~ de~c:r·ib~d.·

(J ahnse~/aI,1986 ).

tr

-;

.

Fiqure2.1 ~2 spray-IceFormation (Jahns at,aI,1986)

bea.cv, eee water hasn~tbeen conSide"red.Lnthis'

e~lanati~n,

i t"'W!!lbe

de'a~t'

^wlt,hiater.

- ~s'^{ecen as'}the waterleavesthe'no~zle^the"j~t breaks' up in~,o dro~s .. ^':he.~~^..~tessure^{-and the} ~n!ti.a.l vel.oc~ty of the jet are known and

. the

"i n i tia l water'temperatur~'is

.. .

,

\ ^.

. .

'),

.. ~~~;';:~;~~ :~~:::~ = :: f ~

• 'i~

surface tension forces a larg~ sU,rface area versus volume ;,.~>

ra tio rej Ults .~catises ~ighheat transferratesanrthe ./~

superCoo~inq

^{of drops. Depending on the.l}oc a t i on

oj

the

:;:~

water, d~oPlets i~_the etream, the._air temp,e.rat~re,~nd ,::~

Character1istics of the trajectory th-e wa t er may nucleate before it^lhits the ground .

Thelana l Ys is.of -t;he"" problem can be looked at -d.n three

,I' .' .- . '

ways; th~velocity

bt

thedrop~

:1n'

the stream, th e'-h e a t an4 '.:.:~

llI.a~~ tra~Sfer

^{of a si ngle drop 'i n}

compa~i'B~nP': to,. ~e t'

eVAPoratiJn rate_sand

the h~at a~d

^Jll1lSS

trans'~'er

^{of a}

s;stem ~;'k

ot

~rop;',

^{\ . · C . . . .}

i

^{,.>". ' . '. ' ,}

. , /;1,;

break~:nla::o~~ e~::::tz~on::i ~ sp::~·::t:_ ::::~::~J:aB ':: .

"','!."._:.'.',:-,'_.»..

".".> '~ ,:l>;,.::':'

With'distabcefromthe'nozzl e

a~:~ the 'ver~ical

^{speed-Of,th e}

. ~,

d~OP _, .decr~~ses, _I.

^to

_' ze~o a~ _.{ i~ _... ' re~t:hes _,

^the

_" to~ ot: '~e

tr a j ecto ry\the n increases again. It is important -In.th'is

~ro~lem

^to

'~ow .

^the'

.dr~p C1~am~ter th:roUg~OU~he

d,lst'apce' . This diameter is not..nece s s a r ily the grain si ze of the

ma t eri al'oJ-t he'

qr~und .

^{.: , ;}

\ ' , .

" .

The heat'and mass transfer of a -s ingl e drop can be

I . . . ^{> •• • •}

.) l oOked. at

] 1 0.

^{two ways.} .~irst it can be aSS:UlDed tha:t. ,

,~QmPlet~'~iiingoceuts.,wi~in,~edr op; and'th~~al'and~ass tr a;"s f e r occurs only at the dropsur f ace..,or no mixing' ca n' be

l'SS~ed ~nd

^{the equationreduces} to a tran.sient

hea~:'

^flow'

~ ' ' . \

.c lQ

-;.5a c ki ng e r 'e t,a1 (1978) inv~stigatedthe'e f f e c t of the the drop cross batenee across the volume -.

used to step through the water.trajectory detenaind ita Properties.

Th~~El; types oJ.,C:alcul~tionshave curves'for a syst.em ot water dr?Plets heights: The~urves are also used.to

temperature.

diameterfO~isqivfnflowrati~and ''':1

F~O!D this~~ype~t calculat~on'thetollowlng information has been"'adcertained:

-

'~ops' t~llitlS1

^·tro.m'a

'gr~at~r

'di s t a n c e

~ool'~more. ,

',- AS.ci~opsize'~ecreaseS"the:~hermal'eqUlli~'con~ition -

bll1t~e~n d~o~s .

^{and'air is}approached.. It is possible,that .;<

drops tailing tr om

' ditt~rent

'd i s t a n c e s

hav'~::'~e-

saiae/tinal"

. ,

-:Ifequilibriumis reached'be t wee n dropa~dhi r ; no turther cOdling,

~f.

^the

d~O;S

^takes

p\a~e.

.

'\

- . ,

^'

.... - A~flowrat,toinc::r~a~es,cooling of drops decreases~ueto the increase of water in the air column.

Th~

^flow'

r,~~.i~

^,-is

di~~Ct1y

^a,

func~i~n

^of

wa~er d~f

~emperatu~e. water flow rate, air flow rate, chan~e'i n air

st~eam

^enthalpy/ and humiditv ratio. .

' P

lost by convectivehe~t^tra$nsterand evap"c;a·tio:n•.

When:

the front

~ide

^{,o f}

~e

^{waterdrop let re a che s -1.8}

~egr~e~c i~e

I

~

crystalsb~9into form. -.s

Hos t water ~roplet:scontain a pa rt i cle of.. sedimen t ,. Whic'tl aids in-

c~Eltal n~cleation ,

^and

-on~y

^a

l~~ited:·-j!Ullount .

of super cool~.ng is 'P?sslblll. Once't he sU~faee of the droplet !~ ice covered~h,et~a'h:ferof.he at byeva.~,~ration, is less.and flow through the sh~ll-Jncreases; ~' As-t:he droplet fr e e ze s, the:brine ccncerrtrrat.Lon

~~maihln~ .

liquidri s e s,a,';1!=1'.~1ie"freezin9-teuip~rature-de~x:ease~. ^• 'Sf thes\ze

o t"

.t he wa~er"d:a::oplet"!s' !.nc~~a_Bed'_.

tpe:

quantity:'o f ,mat eri al to:freez·e.also-increases .~The'larger' the"wa t e r droplet the'ra~terit will,move,thisimprov~i'the_{. .} loc a l-he~t:. transfer in proportion to the square of t:.!Ui"

radius. Also an Lneeeeee in't he nozzlepressure_d~~S not~ necessarily in.crease~,^th:OW distance due't~^.'increas~d turbulence•

Fr om actual observ;ations of spray-ice, th e mean diameter'of~,thep~rticlesvariesa~-f ol lows: 99_p~rcent"are between 1 and 101lUll, 30' pEn:-c ent _ie~s than 4 1lUll-a~.d0"',1 percen~~esstha n' lmm.

Exper.i,mentation shows'thatto ensure an ice content 83

p~rbent

^the

drOPl~t.sho~ld

^{be less}

~an-~-in

\ 12

applications.(Gof f et a L, 19 8 7 ).-

As previously '~entioned , ice. has'.been 'us~

cons t ry£.t l on ma t e r ial inthe Arctic~^tar many;ye ars . ..-s i nce 1970 the oil indu stry has beenu~ in9 flOoding,,sp r'i n k ling and. finally ~pray ice t.echnLqu ea forva rious cons'tr-uctfon":

The use ofice8San enqineerinq mate r i al is ilmited by

.

..

^.-

the extent of the "t emp e r at u r e.: in d OW".t h rougho u t the··yea~.

In the Arctic, construct!Qn o't a~ isl,and or brea klolata r cannot comme n ceun til thesummer brea.kuphasbeen'co:mp let,ed

'a nd telllperatures are cool enough for ice fonnation and

stabilization . . Thisusually :means Dec ember,in theBeaufort see, and both the cons t ruct H:1I1,and the,e~loratorY,dr i lli ng\

. .

II .1. 4tpray-Ice Construction History

13

_~ith ~8:F'Tmainirigb~in~ata salinity of,'200'ppt. ~pray­

ice often contains entrappedair so that; the densityvaries

~etwee~

^0.7to

O.8~~/cm3.

^{- .}

Once the material h~s 'r ! ac h e d the qround, va rious- p:r:oce8~~80C?_~r. Thebrine in tbe droplets starts to;drain and the droplets ,s i nt e r. Si nt er i n g bonds.the ind i vidual ....grains together thus incr~asing the mat~rial st r e nqt h . Accordinq

t.0.::i~eier e~al

⁽¹⁹⁶⁷⁾ sintaring is\he

pr~es's

.by which i.C8 arid sno w particles ,l?otid together at temperatures below the melt ing po i n t. The qrowthof the bonds is a.result sur fac edif~usion, volumedi ffusion and ev aporationcondensation.

partners, ,_{\ '} in

-

.

14 Ex xon.and

.

^/.

. ' .

(Masters on et aa , 1987).

In i916/ 77,'"Un19n oil and I!'~"rtners const~cted/a'

fl~oded ; grount;le.d.i c e islandIn-!a~clUt.2~.7m,etresof,~~:er i~., Harriso~Bay, A1aska. The islandwa s.s_UC~!1ti:;l;s :~llY.use"fo~, the drillingof artBxplorat~on:'BllJc o x'"et al,1986).

Sho:;ens the_a~.lOWab1eexpl.oratton.:::" e.tor "> , ' , spra~-lce islan?s_~n com.paris~n .t o' tba:.~f conc~e:te.caisson

~ .

. ..

^{\ , .~"}

.

.'islands. Gravel.and ecnc e et e i'Sland~, hcrwever, pave very big?cons t ru ct i o n..cos~s^taronet:r.~.~~Xp~~z.=~t~ry^....W~.l.l.~·-a~d^_... only maX'gi~~l succe~s,has;.been acl1~eve~ .i~".t:t::a~~~~i?9 ~.

"con c r et e

~t:~:tures ,y ) "" : loca~i~~s--!

^':'._

~ia·~a.~_~~-1~i~n~~~

obv!'ously. can"not 'be ;-r e l oc ated but -they) maYi :wi th additi onal

lIl~i~~en~nc~ c~~~s;

^be

.u~eci f~~/a s'eco~~s~a~'dn.

.

pa~~i:c.t~c:

^{9'11S 'Ltd.'has"bee n}

c:nst~~~~'~~ :~lo~_t~ng:.

^ice

isl~nds i~'^the canadi~m.highArcttc

since.

^19;3.'To.tl~te, ³⁸

,-' .

."-

^{~ . ', '}

^....

^."

^{. " . .}

^~

wells have be e n'drilled on'islands.const:.ructed i~.t}1is 'ma n ner

in . ";~ter depth~

^{of up;.to}

50o 'mktr~s. ~o~eV~r; J~ 'th~, : sou1;-~Elrn Arcti~,

^the'

~cs s~eet ,is no~

^solid

'(o;~ st_abl~)

^y;ar.·.

rotind.and it i,9 not possible to drill from...floa:tinqiS~ands

):

gro\lnded ice

Bay in 3.05~etresof ~er: The island was approximately 3'96"me t r e s_. in

di~met.er.

_{.J ,} ^Three

techn~es ~ere

_' ^{us ed :}_" ^free_'

flOoding" SPrink~ing^fromacen~^pivot,an~^{spray ingf,rom} a high volume nozzle. It was found that low density sp J;a y-

" - . I ' ' .

,i c:: e could vaetly improve the build-up rate, and' thus constructiont.imes for ice islands (prodanovlc, 1986).

·The.Tars'lut·and Alerkcais~onretain'edstructuresus~d

t~icke!,ed.lc~pads"for their relief wells . Also, further. 'pro t eeti o n against ice sheet for,ge8",was'pr ov i ded,by us~ng_

spr a r -,i c e to he'ightenth~^ice.rubbl e nonndar o un d'th~^.isiand

a~d .'to , en~a~e

^the pad diameter'(He t h et,:1, 1983';"Kemp,

~ ~ . .

In'198 3/8 4 StandaJ;'d

oil

and. Exxon constructed grounded.'

:~praY-iceislands in relatiVtt¥_sha llo w·wate~.~~dcontirme.d

the rapid build- up rates,of spr!"y-ice'lthat ~ad been anticlpate4. ExXon usedaspr~Y-ice,barrieraroundthe'CIDS"

< <"th<

driiling.un i t in 15 metres of wate·r located at Antares in the Beaufort Sea (Jahns et at , 1986). The sa me y,ear, Stan.dard~il and partner...s con~tructed a 10.6"metr~",dlalneter' sp~ay.-ice islandoff.

pru9hoe

Bayin'theAla~;~anSea. .This

.<experimentai island was used,to evaluate the engineering '--:

propertie,sofspray-ice .

Amoco ....as·the first to use a l!p r a Y,:,i c e isl a nd for e~l.graition,drilling. Mars was,p pnstruc t ed in1985/86:at

cepe

Halket t! west; of·Prudhoe Bay in moderate water depth/

15

..-';;,'. ' .,'"".,'

'.'

(Funeqardet'a l , 1987 )~

Since 1980,. Standard oil Lt'd. has been s'i ,;iyinq m"aki nq

use

of rubble

ice.

Rubb l e le8' forms na.t u r a i lf"-6"l1:

slopes'"o f artifici al isi.~ndS·an~shoals', St&.n'dar~ Oil'has de,siqned andtes~~.~rubble ~en,,!rating an~coll,cting dev ice s . An..ex ample of a full-scale fi e l d ~est is the

• I ' .

p~oposeduse of a

I

^bargemou nte'd s tr;;ctur e as'thei~e-:~b~,e, 'gener ator andthep. us i ng spray-icetechnique s to'add to the' . I · . ' . " .

!sland' s mas s (Pot ter,et ai,' 1984)~'

',..~ .·1U1ot~er i:"s~I -,,~f '~sp~a~-ice

^'was

~,~~~~~d

^in.

-1984~~5,

^.:by.

·Panarctic~oils Ltd.,'o n cape:,Ai:l bc:ltt 6-47. Cape A:U lsori c- .i/

~a~"",a

^floating

'i~e' d~'illinq ~l~ttorm ' co~~truC:;:d ..

^ot

f~rst .'yeai:.'~.ea

^-dee

Wh;Ch"W.~'~-_~hifk~~~~ wi~' spr'a~~i~~'~'_ -~~.:

Ori;:Ji~Il ~""'ic;::e',·thlckness;·was'.apprOXilllatelY'0.8iaetre~'. -a nd.the.. fin~l.total'thickne~s'wa s

6 .9;

m~tres, Cape'Al l iso n was

10~at'ed

ⁱⁿ

t~~ ' c~nadian. ~~tiC.

^{oUshore of}

Ellef~in9n ~S

" " ": in 260

"?"

of

"?" ""

it,.co~ered an<;re~ o~

. :

180 by 10 metres . The islandwas designed~o support'the

Pa~arctic

^Rig.

A .

which

wei9~s,

^1.6thousand

to~es (Ma~terson:

^"

et ,al.• 198 7).

e~e~,ience ^{with spray-ice} dU~i~9' ^the'c~nstructi~n^,of

· .

"Buckingham~_0- 68 platform. and're l ie f platfor,m, offshore

·GrahamIsland:

Oriqi~~l1Y, ,~~t-~~-ic: ' wa~ ~o ' b~

^used

so1~lY

for the~reliefplattonn, but due/toits successfulope~iion . and

~iqh

^{build-Up rates ,}

spraY~ice

^was'

u C i~

^{the la t e r}

~sta9~sof constructio n of the mainpl~tfonn. " , 16

17

Generally, eprey-fce is a fairly

.," ,i ' !'

...-.,

..

: ccntafne soft layers.

c,?mpetent material. It;~is composed of fine, subrounded

,

More rec";ntly, in 1986/87, Esso and ~~r.tners conBtructe~a grounded spray-ice platf0'f!'l'.Anq a s " k.La3 near CapeD,!~o~sl~In the Beaufort Sea, forexploratorydrilling and experimental purpos.es (Weaver atal, ~988).

11.1 .5Physical and Mechanical Properties of spray-ice

• . . >

since its first use as a construction .materia;J.o spray- ice has been tested todete~ineits physical andme~hanical properties both In-situand in the laboratory._The improVed knowl~d9'eof the properties of spray..!ce.wi ll enhance.the

• I"

design.of_{vario~Bstru~tureB'.}

The properties of, spraY,,:,!ce vary' with temperature, IO,cation'of'the water·t~ble! salinity; 'a g e . 8tll! p~o~uction' .conditions. Depending en"its use, the strength, volume",

densi~Y

^or

'dryne~s;

^{of th'e}

spray~ic~

^{may be important. The'}

borehole logs shown in Figure 2.1.3 ,s'h o w the ice

·s t r a t i g r a Ph y on two spray-ice construction~ites.

, " '. , , ~

spray-ice appears'in various forms, and it·is worth noting the layering and variabil~tyof'the material. From the profiles in Figures 2:.1.3 and 2.1.4, the increase in slush andth~ w~~er co~tent^{with depthis}eyident,;'_ spray~

ice above the waterline (a.w.1.) isdrained, cold'a"d quite EJ't:,rong, while spray-ice below,t~e waterline (b:w.1.)' is l;laturated, at

;~·a'

water temperature (-1.8

de~rees

^{C)' and}

1••-

\ "

Fi gu ra 2.1.3 Figure 2.1.4

.

Typ(~al

^Spray-IceCorti" Profiles . (Mastersonet aI, 1987 (left); .Jahnsat ef , 198 6.(r i gh t »

18

Over time' the -be m e drains'fr om the

SOLIlI, '.... U.."IIt HOl.U

:t.O U

Y~:*E::::

_<SI'IltOU "

..

fLl,c.aPSUln 44

l.UlIatAIJl~lLS

IlORIIIa:

..

~II'llUDnun

I.c.u-Jn'LU!lICI:

• . .

• •

'.C.1^{JLU'H ICt}.~,^/""t1I/U.L~ II'S1'Ic:J!

.. .. ..

unttozen brine,'

~.gr~!,ulesof iceWhic~may' be bonded or partiallybonpe.~•.I t

tan~st,o'ci~nsolidate and become'moredense.withinc r e a s i ng C1vet:burden pressur,. Above the water table, spray-ice is d~positedLn.layers , !lea solid granular~aterialincludinq-

I Grain :site s for spray-~cevary.from 0.5 t~~./;

5.0:IIJl.

The qrainsizeat spray-ice depend s 1Ia 1l1l )l onthe type

, /,

of epray nozzl _ us ed and the"cl1.at"~c cond i tion s du;'i nq con stru c t i o n.

\

The spraY~lce is in it i a lly formed·at a tempera t u re of

"

.

about ~1. 8·degrees C. The ice then quickly cools in the- cold a~ctic.air. 1:n th e early life of the island tJ:le ice

.

- .

.' -

te Dll?erature·is quite variab le , bu t as ti me pr ogre s s e s the

. , " . ' .

ice eurf~c~ c:ome s.close to air temperat ure and th e ice' t~mperaturegraduall'9\increaseswith depth untilthe wllte~'

/

19

,

^'

partiallybonded aaterial . Belov the

w~t8r ^table,.

^the'

~~raj­

ice'

~in~~ln8

^'II'

··therm~yn~iC ~quil;~brlUIl Wl~'

^the'saline

pore.tl~id'(Goftet al.•1987 ). ( . .

The pr o pe rtfe llof' spray-ice at~highly dependent on ice"l'"

.t-' .

type and, there'fore, distan ce to,the water level. The s~linityof spray-ic ealsocha~e8 wi~depthandtillle~ The a.w.l . salinity' avera g es lowe r tha.n the b.w.l. salin i ty.'.' qve r ,time, the a.w.L salinity decreee e e:due

tci

bt:~ne. drainage and brine migration." Brine drainage and migration',

ar e

'initia~ed d~e

^to"the,force

~t 9'ra~1ty,

^{,a nd}

tempe~atbr~ i

,

q~adient .

^{acting on th e dense r.}b"rine'over the-

surrou~nq

^\

.:sp r ay-.i c e.

~~~~. ~ffects. ca~Be .~ c~~res~o~ln9 'i~cr~a~~'

^in'"

,the~.~.~. ~lll1n!ty of'" "iC~\._Onaver:a~e:th esa~i~ity.J.e ', o u nd"...7 .4_ppt. \~. w. ~.and 16'ppt: b.w.!. spray-ice \'

(Prodanovic, 1981(II)f. The salinity of" sea w~ter..is \ approximately3~ppt: .

,<

, , '

for b.w.i.

2.

, ', ,"

Sor;.dex tub,es, .ve rti c al and horizontal slope indicators..

s?rvl1ylillJ,equiP~ent. .:

leV~l

water telllperat~lre of 1,86) •

The density of spray-ice not

SpraY-i~~~

"By.'

cor'~ng through "h~~and~.the eXist~nc~'·~t. layering,~t'the.spray.;.ice-:·has be~n e~abiiBhed,.'s~me,· :'ot·

. ' ." . ". . . ;r..•. "

these,layers are,solidic~. oy-dng'i c e.pr.od1:1cti~n:~p~a~iilq. 'isstopped,inte'riDitte'n~lYt~ all~wthe.lIlat~rial :~ s~liC!ity.. At times, when the alr:,tempe r a.t ur e is,r~l~ti~elY .h1g~',ice lenses,fom. 'A'de nsit y and brine"volum.&protll~f,r ? m~e EiSOResources Ltd.'A~erk^{gro\J.nded·spray-ice}~pad^{li s}shown.i~

'Fi gu r e 2.1.5••

S~ve~al types ~ffield'a nd laboratory tests'have been

CO~ducted

^'in'o r ; e r to

.dete~ine . th.e

strenqih,..

a~d deform~tio~

1,.., .. •

prope~iesofspr ay - i ce ." The,s t r e ngth~fspray-ice has been

,e~timat8!l fr'om.;n'~si~U·p~netr0f'eter:'t es t s; f~atj~Ck't,es.ts_·

andpress~relll.e,tertests. vertical and horizontal.settl~ent

~f the spray-ice structures

was

_G~amini:.d through the~se^of .'salinity. temperature and'distance to ~e ~tersurface,

but is also a function'of .t he meteorological,..conditions during

:co~s~ruction'

^{.a nd of} 'the Jroduction,

EiquiP~ent.

^Th.J.i

porous material has a bulk'density on'~verage'Of"O. ?4',g/cin³ which islower'thansolid ice. Bulk densities varJ.between

\

Fi gure 2.1. 5 .

I~e

_(Ke,mp^Island_{·, ~984)}^{De nsity&salin i t y}

~otile

/ ; ' .

t:~ _{I ',} ^{D .} · · . . .. ^{, .} _. ^{. . ,} b= _. .

~. . ' I ·

I .

0100 .

--

too. 100 1000.

^_

•

^.... ..

• t:I

.'I t

-appear~

th a t

.ec~~nlcaI ·prope~·ti.es

of'spra Y- ice

ar~'

-.

:funrl~i~~S ~f

""'t he

. ,~artlcle'- bOndi{l ~ '

^{,loa d ing}

~ate, s'tr~$s

reve t ,"'temperatu~e: , salin~t;, den~itY, and o!Ii~ and \' 01d;- vcauaes, The shea r streng~h is'ge:ne rally C?.?nsidered to be abo ut.half of ' the uniaxial co£pre s si v e- strehgth :'" The' stre~~thof·spr ay ;"iceha;be e n measu redfr omt~iaxial tests

..rp~~f6~ed'~n

_{" iI:} ^{'ice cores ina''h e l dt}_.:^esting_{" _}^facility_{- ':"} ^{as well}

aS froVns~u t.es~~. ·~~.essuremet"e~,and f~at~aC:.k.te sts , p

.

~ovid~

^{an .00t 1••t8 ot Yo ung ' .}

ModU1U~ . ~

^{• r} spraY- i c.e, th"at

~ }suse.tpl~n'predict.~ngthesettl~. .

'. ,Field. ,t:s st. s hav e the ~dvantage of,te sting in-

pia:e

mate:f'l a l: aeveve r-, the s e,te sts,ar e expens i ve and"s~j e~'t7to. .

th'~'

^{,t ime""c}on s t;i-a in ts

impos'~d

^by.

is,;an~. · ~r

^.

~a . i~ier

c~stru9tionanddril.~.ingtimes. aeceueeof this , the r '21

/

spray-leecanbe produc.edin~e'l abor a t ory'i~a manner

·simila r....to thelllethod used. inthe.field . A~oizleis uSed_.

, ~

. . . .

" '.

to spray water.droplets in th~ air, :--here it'.fre8zes into'-,.

ree qranules. 'the n?zzle . ls fed ~ith compresseda~rand.

sal1newater•.E;ui pment usedtoma~e'art~ficialsnow.canbe adapted for use.I n'pr oduc i nqspr ay-ipe .

In the laboratotYI triax ia l tes t s areus ed to c1ete;;irie

, ' -l " " ,'

icep~perties., To simul~t,e.site~~nditions,drained'and undr~ined'testshave"been 'ca rri ed out atdi!!e~nt'6orifininq,

" . , ' ' "", , , ", ' ','.. "" .

~ressur~.s, ,~eJ!lpe7aturesan.d~train,ra~s: ~ese~es~s,.~r~

conducted,on,epr~y-ice'c~e sampies transPorted' to:'the

.' , ,', ' , '.' , ' ' ., i'."

v? .

laboratory, and on' .samples ma~e''''from reconstituted field spray-ice.

'the stress-strain strength.characteristics,of the

',' '

spray-iceas det eninedin controlled'triaxialtests

can

be'.

used 'toestim~~e_,the'deformation modulus_" and,a~ticipated_, , settlement. However" it has been found that ft is dit'ficult to ~xtrapolate ^{laboratory data·t·o lonq} t e1"lll set.tlem~nt deter~inaJdon (Ma~, 1988); More recentiy~ the'·"cre.~p

behaviou~ f~r

^{spray:i·ie ',ha s:}

be~n ' dete~ined thr~\iq~

^,

cor.stitutive -~a"'-

^·and'

num~rical

,mode ll i nq(Man , 1988 )'.:

. '~he~~ ^.

~analvses make use'of thE! +_imited: .f i e ld observatlo nst

example of,a's implified stress-strain,curve.

1 ;

22.

spray-ic;e island·is shown 'i n.Fi qu r e ~.1.6, ^The.str~in hardeningb'ehaviou~ ~tthematerial is'quJte evident.

--

Figure2,,1.6 . Simplified Stress-sttiI'r\.CUrve

(Weaver etaI, 1988)

T;ble2.1,...1~nd 2.1.2s.how'~c:'me~ypicalva:w:;~-t:~the eiastic modulus'and compression.strength of spray-ice from laboratory and tfel~d::,ta.

From th~ te,st datacOllec~edon spray-ice, it appeays .tha t laboratory e.xperimen~son tield~orlabora,tory spray- samples,give rea~oriable esti;aates of the field st~ength.and el~stic modulus yalutllil. The'

tend'to underestimate both the elastic the strength values, although't he y ar~'~ithin Itisdit"ficult 23

to ':'lo mp a r e the results without knowing all the..test cond i tionsand indiVidualspra,y-icepr9pertles.

,.

.

•• U

^{. .}

I.U 11.1

lUI

,n

lUI

'n

lall

".

Il, . lUI

/"

.. U"(" Pol STD.nu.II'"

.ICE PROPERTIES.

COHFINl!O ·ItNCOHFlHED

O~

"""'"

'~¥rt7J~g:1 COMP~ U5 lYl!

.g... .~

'MP,

m;:Dt

SP~E D 5_0 10170 0.5-10',0 MU'U 0-2.I-rciO

~....I-U"C CDHSDUDAUQ110101'0',OIOI$.D MUM

".

^0'&1.._1)"1: 1.

ICE~UBBLE U711_U"C

Table 2.1.1 Spray-IcepropertJes I (Mastersonlit a1, 1986)

Table2.i.2 Spra y-IceProperties II (Kemp, 1984)

z.

h .."n n l" e ,....~..10.1 ..

P .,

nOll..

Do..~ J'c~

....~~l. .'.l .... I,.. Al.1 J...n"ln.p ~. .la.l~~.~

::h:~' \

Allis~nC-47isl~nd,quality tes'ts.were performed to compare flooded'a~d'^spray-iceprOpertie~. As shown in FigUre2.1.7"

the materials are ,~ot' significantly.''dift'e r e nt for the testin~techniques empl ctyed, but't h e rangeof values can be'

p\..ltJacr;.

n.n lIUIl

CON'INU,t,T VNCOIfPUIIDU t·U I·Va t_U l!·I/.

\ ~;.;25

\

Illlll!tIOlI:

~"'Clln'T' COIfI"INI DU t.~II1· lJa

-==::::=:===

i . ..

--V

..

^O,LOQDI!OIC!

. S....taoICI

! ^..

"IUIYAWI

..

r--' ,----'

!

^o-

r ^{."- {Jt--}

\

Figure2.1. 7

Ic eQualityTe st s onspr a yand Flooded Ice (Mas~e~sonetall ~987 )

r

large.

";;

·:(i;-d,:?\~;~;::"'i;,,;,~\_"~'.' !-v".···."\I'i~,.",w~'"~"" p:.

-' ..

~ ;d:~"'. ~I.I,...;~~( '!f~"'l{"" y..j , ~

'. . ': '. " " ' ''-', ' ,.:: . ... :.t:s~:I;!~11

11.1.6 DesignConsiderations using spray-Ice • ~..~

\ As

mentlon~

pr ev iously, sp r ay-icecanbeusedforlIeny ' .,...) construct ion purpos.e s Includln9 barriers, .tloatlnq island. ' :

~\.

and gro un ded. islands. Inor d er toattain apers pecti va on .

s

.the.

~e,lqn conce~a

^of structur es

U8i~ . spray-~ce,~

^..

~~

I '!,

i/Mtuea pert i ne nt to II grounded sp ray-ice bland '0(111 be ":":;;

brieflyout l i ned. •

~

^..

^j

Severa l gr ou nd ed ice islands havebeen ,const ruc t , but

< ~~

':'1 few hav e be en ac t ua l l y used fo r expl o ratory ddl 1n9. .<:.~

Reasons fa:r thi s 'a re: the newn ess of ~pfaY-ic. :?:~

l :' "

te chnology , it~^..somew~.~~,.^{limi t ed",}ap~l~.~~'i?~~,

, rd .

^{',.th,e, 'h.}

d~cIlne

^{inoil pric e •.'}

""ii• •

^::th...

~.~~:.i~ilitY 'stU",i~~ ~l

ca s e s are addre'ssed:'.the( practibai ity",o i~cotisthietin9-__~ ,. ').

,island

W~~in ~e

give'n time

constr~i~_t8

^and

^the" ·~t~ulty ~~

,of

~n

^{ice i.land und e r latera l ioading . .Othe r 'i},;po" ' ;n"

,)~

issues arethe thermal"stabilit y (e spec ially duringsprilnq, ~ br e a kup ) , the,'

eettle.en~

of the Pad,

the_:~

^.tabtIlty"and '':,',:3:;'..

the.~stotconstructingand operattnqthe·islanc:l. ..}

Const ruction can'not' c01lllllence"until th~^{ice sheet' "1_}

stab le so that.upp·l1~sand equI pment.can bebrough.t in on

ic e"roads'. It1&also requi r ed toconstructtheisland.1na ::;1

" rest\-1ctec:t~,t1me

^periodin order tocOlllpl-:t e

~e ~~loratOry ;

^,

< :f

drilling

b~fo~e,

^{the.p rIng}'b r ea kup. A typic al'

c~n.tru;';i~n"

^'J

,:;!~,

~chedUle^is"sh6 wnonFlqure2'.1.e. ~

ThI3:major torcesacting on the iceisland.a r e lateral

'"~:";~

loa~s: impos ed by the ice sh ee t and th eweight

ot.

t"h~

26 .''.t

~'~·~~ci"';"~:c.'i:.;.j;;"",;.

^v.,

. ":.:,.:.:.,~, :',,i;;..;,~.:~,~,,~ ^.. ,~:i~:.,;;.d.;~'C; ;f':'-:::":~:";;:tJ,~{J

island in a landfast ice :z:~ne-are usual l y de scribe d by di,crete

ev~n~tacteriZ ~ed

^by

large~

^sudden,

i~e-field

motions. .

~

Fa ilur-' can occu r in several ways, 'due to th e interaction of the spray-Ice island and th ice sheet.

/. There may be"'initIal,crus hing 'ot" ~he'ic e sheet, local failure of th e"spray-ice at the'.e dge of the i~landl

27.

Construction Schedule (Gott'at a1,-19 8 6 )

t.he island. The Ice forces acting on 't he Fiqure 2.1.8

SPRi\ \ICE'ISLANO.SAl lOW CON,STRuc;'ro..N AND USE

FO~

, E.(.LORAT'C:>~ ORILLI"GIN ONE WINTERSEASON.

,

.

SEPT 0<C1jj'OYDEC

IJ"'''' ,!~

^"'''''APlliLIotA'l'JUNE JULY'

IC' FIlE!!ZI1 UP 8AI.... KUP

ENVIRONM ENT

- -

Sl" AAY ICE ^{CdHSTAUC TlON UI!LTING}

ISl.AND

-

DRIl.l.INGAND

-~

TRANSP ORTATlON le a ROA D •

o' OR...eO ES' 1

~

~

2·3 MONT HS

.equipment

.~

.

)

\'

. "

II. l.7 Proble ms and Impr ov ement s':in sp;-aY-Ice"Stt"Ucture

,

" .

,

•large se t t l e me n.t s,during. theli t e ti meo,t the pad, the8hO~

~constructionperiod,

the

p_artia,~me{":.inqot'theisia.n~a,:·'^the w,at e r de pth lim,!ta tionsandthedev.lopm~nt,ot'cr ac ks in the

, ', '

.

",

!sla nd.

The problems'as s'oe lat e d ....ith the tormationotspray-ice

. ,

, "

^.,

28 ' .' ,

, ,," .

ari s e"dUri n'g'..spr.aY-ice, Pr obl e . s that

Design

gIObal_lIIov~;;t-:;~· _. "." . v. , . - "

^{the-'island'due}

. ' . :."

,~e iSlandand..tl1!..8eabed~r'o ther Crit1~~::alid~g'Plan~~

thr ou gh the isla nd. In the des.lqn ot the island., itis b ;o rtant to

en~ure

^.•

th ~

^the

~atter', 9-10b~'i "·.ov~l:Ie~t 'cf :th.~

' isla~d.,

^{does not occur.} There tore, the

i~an~

^is

d;Siqn~d.'

wi th~nouter~a)itiCi;1e~ge20n,e, or in~~.raction ~.r~n~ .

which maybe pene tratedwitho~t,at te c t i nq the actualisland. It is ant ioipate d tha t

the

outer ~ringe wHl.:.taii if!.a, passi7'e~.edgetailure.w~iCh,willind uc e.a ~er"!di~~mome,n~.in the natural ic e sheet. Thi s will o~use t!:ie'ice shee~_to - brea~.int~_rubble and thus ~ower th~ l , era l l~a~ on'the.

isla~~as tl,1e'fleXural st rerwth'ot ,the ice.sheet is muc h.

less.than'i ts crushing strength;· 'The'ditte~e~t~mod~s o·t. tailu;e

or

^tite

'ic~ . pad"-are ~hoWn

^{·i n}

Fi~r~ ^{2 ':1.9: ' . ,}

-.;.-