Investigation of Ice Problems in the Construction of Hydro-Engineering Structures in the USSR

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Investigation of Ice Problems in the Construction of Hydro-Engineering Structures in the USSR

Proskuryakov, B. V.

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Russia 2nd Canada. occupy s l r n i l a r p o s i t i o n s i n t h e FJorthern !:en1 sphere. Russian e n g i n e e r s concerned with t h e c o n s t r u c t i o n end o p e r a t i o n of h y d r o - e l e c t r i c i n - s t a l l a t i o n s a r e t h e r e f o r e faced with t h e same problems c r e a t e d by t h e formation of i c e a s Canadian e n g i n e e r s .

During t h e 8 t h Congress of t h e I n t e r n a t i o n a l A s s o c i a t i o n f o r Hydraulic Research, h e l d i n E o n t r e a l d u r i n g Aumst 1959, t h e r e vras conducted a seminar i n which t h e s e problems were d i s c u s s e d . To t h i s seminar,

D r . R.V. Froskuryakov, D i r e c t o r of t h e All-Union

S c i e n t i f l c Research I n s t i t u t e of Hydro-EngJneering a t Leningrad, presented a paper ( i n ~ r e n c h ) which summarizes c u r r e n t Russian t h i n k i n g i n r e l a t i o n t o a number of t h e s e problems. I t was considered that t h i s sumrnal*y of Russian p r a c t i c e I n t h e f i e l d of h y d r o - e l e c t r i c i c e e n g i n e e r i n g would be of i n t e r e s t and value t o Canadian e n g i n e e r s and so t h i s t r a n s l a t i o n was prepared.

M r . J . K . Sexton, Chairman, Technical Programme

Coln?~ittee fo r t h e 8 t h Congress of t h e 1.A.II.E. s t i n ~ u l a t e d t h e p r e 2 a r a t i c n of t h i s t r a n s l a t i o n by M r . S . A . Gavrel.

The checking and e d i t i n g of t h e clra.ft was done by Y r .

B.'.i. Henkin of t h e Montreal Engineering Company Limited.

T h e N a t i o n a l Research Council i s p l e a s e d t o p u b l i s h t h i s i n f o r m a t i o n i n t h e i r technl.ca.1 t r a n s l a t i c n s e r i e s . Ottawa J u n e , 1961 R-F. Legget D i r e c t o r

NATIONAL RESEACCF COUNCIL OF CANADA

Title:

Technical Tra.nslation

961

The investigation of ice problems in the construction

of

hydro-engineering

structures in the USSR

(Travaux concernant les probl&mes

de la cryologie (la

glace et

la

technique) dans la construction hydro-

technique realises en URSS)

Author:

B.V. Proskuryakov, All-Union Scientific Research

Institute of Hydro-Engineering and Land Reclnmation

Reference:

Paper presented at a seminar of the 8th Congress of

the International Association for Hydraulic Research,

Montreal, August 1959

THE INESTIGATION OF I C E PEOBLEMS I N THE CONSTRUCTION

OF HYDRO-ENGINEERING STRUCTUFES I N THE USSR

I n t r o d u c t i o n

The r a p i d development o f h y d r o - e l e c t r i c p r o j e c t s i n t h e USSR

i n t h e l a s t 30 y e a r s h a s given r i s e t o new problems f o r S o v i e t i c e t e c h n i c i a n s t o s o l v e . T h e i r e f f o r t s were d i r e c t e d mainly towards developing new methods f o r t h e c o n s t r u c t i o n and o p e r a t i o n of hydro-engineering s t r u c t u r e s I n t h e s e v s e c l i m a t i c c o n d i t i o n s of t h e S o v i e t Union.

I n o r d e r t o s o l v e t h e s e i c e problems, S o v i e t s c i e n t i s t s had t o d e v i s e methods f o r t h e d e s i g n of thermal and i c e regimes i n water- ways, forebays and r e s e r v o i r s and t o f i n d ways of overcoming t h e d i f f i c u l t i e s caused by i c e d u r i n g t h e c o n s t r u c t i o n and o p e r a t i o n o f h y d r o - e l e c t r i c p l a n t s . Problems concerning t h e a p p l i c a t i o n of a r t i f i c i a l f r e e z i n g i n c o n s t r u c t i o n were a l s o s t u d i e d . The work of t h e S o v l c t s c i e n t i s t s i n t h e f i e l d of i c e e n g i n e e r i n g i s b r i e f l y d e s c r i b e d i n t h e f o l l o w i n g paper i n o r d e r t o show t h e p r o g r e s s achieved. The C o n s t r u c t i o n of H y d r o - E n ~ i n e e r i n ~ ; S t r u c t u r e s i n Winter

Before 1930, e a r t h moving and c o n c r e t e pouying on a l a r g e s c a l e were done I n a c o n v e n t i o n a l manner d u r i n g t h e w a r m season.

I f work on hydro-engineering s t r u c t u r e s continued i n w i n t e r i t

w a s p o s s i b l e o n l y i n c o s t l y h e a t e d s h e l t e r s of heavy c o n s t r u c t i o n . B u i l d i n g t h a t way was a l e n g t h y p r o c e s s and i t caused d e l a y s I n t h e commissioning of t h e p l a n t s .

As e a r l y a s 1930 t h e need w a s f e l t

i n

t h e USSR t o b u i l d hydro- e n g i n e e r i n g s t r u c t u r e s a s much a s p o s s i b l e throughout t h e y e a r s o t h a t a permanent l a b o u r f o r c e could be maintained and s o t h a t t h e o u t p u t of cement f a c t o r i e s as w e l l a s o t h e r p r o d u c t s and b u i l d i n g equ.lpment could be used t o f u l l c a p a c i t y a l l y e a r r o u n d .

Building i n t h e USSR i s no longer seasonal. Construction now depends on how well t h e b u i l d e r s have prepared f o r the winter season.

W have achieved these r e s u l t s because e w e have developed new methods f o r winter c o n s t r u c t i o n . Ye may say t h a t t h e USSR a r e ahead of o t h e r c o u n t r i e s i n t h i s f i e l d . Studies made by Soviet s c i e n t i s t s and engineers l i k e

P.I.

Andrianov, A.N. Zelenin,

V.S. Luk'yanov, M . I . Swngin, I . A . Tsytovlch, N.D. Averin and many o t h e r s have contributed t o t h e development of new methods of s o i l p r e p a r a t i o n i n winter b u i l d i n g which have been used f o r t h e f i r s t time i n the world.

Analogous s t u d i e s made by Soviet s c i e n t i s t s and engineers l i k e N.F. Khotsialov, S.A. Zironov, B.V. Mikhailov,

V.N.

Sizov,

P.A. Rebinder, e t c . a l s o contributed g r e a t l y t o t h e e l i m i n a t i o n of t h e i n f l u e n c e of seasons on building.

Earthworks

S o i l s can be prepared f o r w i n t e r c o n s t r u c t i o n by one of t h e following methods :

(1) p r o t e c t i n g s o i l s from f r e e z i n g

( 2 ) loosening of frozen s o i l s ( 3 ) thawing frozen s o i l s

( 4 ) s p e c i a l processes

protect in^ s o i l s from f r e e z i n g

This method i s t h e most economical one f o r c o n s t r u c t i o n d u r i n g t h e f i r s t two-thirds of t h e winter. The s o i l s can be p r o t e c t e d e i t h e r by covering them with i n s u l a t i n g m a t e r i a l s o r by employing s p e c i a l measures.

S o i l s may be prevented from f r e e z i n g with i n e x p e n s i v e i n s u l a t - I n g m a t e r i a l s such a s can be obtained l o c a l l y , e.g. l e a v e s , wood shavings, sawdust, dry moss, f i n e p e a t , straw mats, s l a g s and a l s o loosened s o i l o r snow'''. The s p e c i a l measures include t h e damming and f l o o d i n g of t h e s o i l surface t o be t r e a t e d , with consequent

f o r m a t i o n o f an i c e c o v e r 1 0

-

GO crn t h l c k and a c h e m i c a l tmat-

txent r e q u i r i n g t h e u s e o f calciurn c h l o r i d e ( 3 , and s u l p h i t e - a l c o h o l d r a f f a ( 2 ) Loosenin~r: o f f r o z e n s o i l s The l o o s e n i n g of f r o z e n s o i l s f o r c o n s t r u c t i o n p u r p o s e s ca.n b e (4) a c h i e v e d by b l a s t i l z g o r hy m e c h a n i c a l methods a ( 3 ) Thawing f r o z e n s o i l s

Heated s h e l t e r s are n e c e s s a r y f o r thawing f r o z e n &-round. The h e a t , i n t h s s e s h e l t e r s , c a n be produced by steam o r e l e c t r i c i t y .

Hods h e a t e d by steam, h o t ? l a t e r o r e l e c t r i c i t y a r e widely u s e d f o r e a r t h w o r k s d u r i n g t h e c o l d s e a s o n ,

( 4 ) S p e c i a l p r o c e s s e s

The

c o n s t r u c t i o n s i t e ca.n be p r e p a r e d by c u t t i n g t h e f r o z e n s o i l i n t o b l c c k s . The c u t t i n g can be done w i t h a c u t t i n g machine o r b y m e l t i n g t h r o u g h v e r t i c a l p l a n e s a t right a n g l e s s o a s t o o b t a i n b l o c k s .

The p r o c e s s t o be used f o r p r e p a r i n g t h e c o n s t r ~ ~ c t i o n s i t e de- perids on l o c a l c o n c l i t i o n s and on t h e t y p e o f equipment a v a i l a b l e .

( 5 )

The c h o i c e i s i n f l u e n c e d by t e c h n i c s 1 and economic c o n s i d e r a t i o n s

.

C o n c r e t e Work i n Winnl;er

--.----.-

I n t h e p r a . c t i c e o f b u i l c l i n g l a r g e h y d r o - e n g i l i e e r l n g s t r u c t u r e s i n t h e

USSR

o v e r t h e l a s t 30 y e a r s a b o u t a t h i r d

of

t h e t o t a l volume o f c o n c r e t e w a s poured i n w i n t e r . The f o l l o w i n g f i v e c o n c r e t i n g methods hTere w i d e l y used i n t h e b u i l d i n g o f h y d r o - e n g i n e e r i n g

s t r u c t u r e s i n w i n t e r :

Eu!..l din,? i,li@_r heat.ed skeltel:s o f heavy cons t r u c t ; i o n

T h i s method b r i n g s a n i n c r e a s e 19 c o s t of a b o u t 40

-

60% i n

comparison w l t h silrnmer c c n s t r u c t i o n . T h i s method was used f o r t h e b u i l d i n g o f t h e V ~ l k ~ o v s t r o i and S v i r s t r G i p l a n t s u p t o 1 9 3 2 . The

s l i e l t s r s used ~lcwr a r e l i g h t e r and. t h e i r walls are f i l . l e d w i t h i n s u l a t i o n .

The thermos method

I n t h i s method t h e m a t e r i a l s making up t h e c o n c r e t e m l x t u r e a r e preheated and. t h e concllet.e i s p r o t e c t e d from f r e e z i n g with heated forms and t a r p a u l i n s u n t i l i t r e a c h e s 50

-

70% of t h e de-

signed streny<tli. This method i s widely used i n consl;ruction. ( 3 ) P e r i p h e r a l e l e c t r i c he2>ting

One way t o p r o t e c t t h e c o n c r e t e from f r e e z i n g i s t o h e a t i t s s u r f a c e e l e c t r i c a l l y . With t h i s method no h e a t e d forms o r s p e c i a l t a r p a u l i n s a r e r e q u i r e d up t o a c e r t a i n temperature. Although i t

r e q u l r e s t h e use of

a

network of e l e c t r o d e s , condu.ctors

,

tra.nsform- e r s and e l e c t r i c power i t i s l e s s c o s t l y t h a n t h e thermos vethod.

I t was used s u c c e s s f u l l y d u r i n g t h e b u i l d i n g of t h e Gorkovstroi p l a n t a s e a r l y a.s 1952 and t h e Kuibyshevstroi p l a n t from 1955 t o 1957 ( s e e r e p o r t s by K.V. Alekseev and B.V. Mikhzllov p r e s e n t e d a t

t h e meeting h e l d a t Volzhsk, S t a l i n g r n d g l d r o s t r o i , i n October, 1957). T h i s new method h a s t o be developed f u r t h e r and r u l e s w i l l have t o be e s t a b l i s h e d f o r t h e s a f e t y of t h e workers.

Steam h e a t i n g and continuous e l e c t r i c a l h e a t i n g m e t h o e

These methods have been used i n t h e b u i l d i n g of c o n c r e t e i n - d u s t r i a l s t r u c t u r e s ns w e l l a s i n t h e making of p i l e s , p r e f a b r i c a t e d c o n c r e t e p a n e l s and p r e f a b r i c a t e d r e i n f o r c e d c o n c r e t e s t r u c t u r e s , These methods i n c r e a s e c o n s i d e r a b l y t h e c o s t of c o n c r e t i n g ( S . A . Mironov "Theory and methods of l a y i n g c o n c r e t e i n w i n t e r " ; V.N. Sizov " E u i l d i n g under w i n t e r c o n d i t ~ o n s ~ ~ . )

.

A t t h e p r e s e n t t i m e , p r e f a b r i c a t e d c o n c r e t e p a n e l s and c o n c r e t e s t r u c t u r e s a r e made w i t h q u i c k - s e t t i n g c o n c r e t e s without steam

h e a t i n g .

The c o l d c o n c r e t e method

Unlike t h e p r e c s d i n g methods, which r e q u i r e t h e h e a t i n g o f t h e m a t e r i a l s and of t h e c o n c r e t e i n p l a c e , t h i s method c o n s i s t s i n p r e p a r i n g t h e c o n c r e t e mlxture w i t h . m a t e r i a l s , a t t h e i r environ- menta,l temperatures (down t o minus 2 0 ° c ) u s i n g aqueous s o l u t i o n

c o n t a i n i n g 10

-

25% of calcium c h l o r i d e o r sodium c h l o r i d e .

The

c c n c r e t e mixture i s poured i n t o a n o r d i n a r y non-heated form I n t h e open a i r snd a t t h e below-zero temperature o f t h e c o n c r e t e mixture. Since t h e aqueous s o l u t l a n s of t h e s a l t do not f r e e z e , t h e water

which i s n e c e s s a r y f o r t h e c u r i n g remains i n t h e c o n c r e t e . Vith t h e z e a d d i t i v e s , the c c n c r e t e hardens a t t h e below-zero a i r tem- p e r a t u r e , t h e s t r e n g t h cf t h e c o n c r e t e h a v i n g t h c f o l l o w i n g charac- t e r i s t i c s : a f t e r seven days, about 30$, a f t e r 25 days, 60

-

70% and a f t e r 60

-

90 days t h e c o n c r e t e r e a c h e s about 100% of t h e s t r e n g t h which a c o n c r e t e of t h e same c o m ~ o s l t i o n , c u r i n g under normal c o n d i t i o n s , would have a f t e r 2 8 days without t h e a d d i t i o n of

s a l t . The i n c r e a s e d c o s t of such a c o n c r e t e i s less than f o r t h e thermos method. The use of such a c o n c r e t e i s l i m i t e d t o s l a b s f o r c o v e r i n g s l o p e s , t h e b u i l d i n g o f s m z l l n a v i g a t i o n s t r u c t u r e s , i r r i g a t i o n c a n a l s , and housing. This method h a s c e r t s - i n p e c u l i a r - i t i e s which must be t a k e n i n t o c o n s i d e r a t i o n ( s e e i n s t r u c t i o n s on t h e p r e p a r a t i o n and t h e p l a c i n g of " c o l d c o n c r e t e " ) . I t i s n o t recommended f o r t h e b u i l d i n g o f r e i n f o r c e d c o n c r e t e s t r u c t u r e s be- cause of t h e danger of c o r r o s i o n .

The "'3idr@proektt1 I n s t i t u t e , t h e O i l I n s t i t u t e of Moscow, %he S c i e n t i f i c I n s t i t u t e f o r Hydro-Eiiglneering Research ( V N I I G ) , e t c . , have p a r t i c i p a t e d i n t h e development o f t h i s method. It was f i r s t

a p p l i e d i n t h e c o n s t r u c t i o n of t h e Volga-Eon c a n a l d u r i n g t h e w i n t e r o f 1951-1052. L a t e r on, i t was used d u r i n g t h e c o n c r e t i n g of a

few monoliths a t Kamgesstroi, Gorkovgesstroi and some o t h e r hydro- e n g i n e e r i n g s t r u c t u r e s .

The above-described methods of w i n t e r c o n c r e t i n g meke i t pos- s i b l e f o r t h e monoliths t o be l i b e r a t e d from t h e i r forms i n a s s h o r t a tlme a s p o s s i b l e , On t h e o t h e r hand, a c c o r d i n g t o t h e i n s t r u c -

t i ~ ~ l s gl-ven f o r cor:cretlilz i n c o l d weather, i t i s n o t p o s s i b l e t o rernovo t h e forms u n t i l t h e c o n c r e t e r e a c h e s from 50

-

70% of i t s

2

r e q u i r e d s t r e n g t h and n o t l e s s tlxm 50

-

G O kg/cm f o r low-strength c o n c r e t e . These s t r i c t r e q u l r e ~ n e r l t s make i t liecessary t o keep t h e c o n c r e t e In t h e forms f o r 5

-

7 d a y s a c c o r d i n g to t h e type o f t h e cement, t h e composition of t h e c o n c r e t e and t h e weather c o n d i t i o n s .

I t i s t h e r e f o r e n e c e s s a r y t o i n v e s t i g a t e e v e r y p o s s i b i l i t y e f r e -

d u s i n g t h e c o s t , , a c c e l e r a t i n g t h e c o n s t r u e t i o n and Zrnpl-ov1.n~ t h e (-luali t y o f t h e work.

For t h e r e s t , t h e 14rorking t e c h n i q u e s d 9 c o t d l f f e r from those

employe4 i n surnmnr. I n adCLi t i o n t o t h e b i b l i c g r s p h i c a l r l - : f ~ ~ ~ - ~ ~ ~ ~ c c s $ven I n t h l s s t u d y , we a1:-30 recornr!lend "Instrucl;Lr=itls Cor t h e

e x ~ ; c u t l o n o f w i n t e r c o n c r e t i ~ g i n t h e c o n s t r u c t l o p l of h y d r o - e l e c t r i c p l a n t s " ( All-Unlorl S c i e n t i f i c E n ~ i n e 2 r l n g and T e c l i n l c n l Soc:ety

f o r B u i l d i n g , G o s e n e r g o i z d s t , 1 9 5 4 ) .

Methods f o r C a l c u l a t i n g and F o r e c z s tin^ !dater

-

Temperatures I n Rese-rvolrs and !laterways The maln p r o b l e n s h e r e a r e the f o l l o ~ . ~ - i n ~ ? :

( a ) t h e d e t e - r m i n s t i o n o f t h e v n r l a t i o n of t h e w a t e r tempera-

t . u ~ e a s a f u n c t l o n of tlme I n r e s e r v o l r s w i t h o u t i c e c o v e r , t h e de-

tzrml-riation o f t h ? time i i e c c s s a r y f o r t h e r e s e r v o i r t o hecor!le f r o z e n , and t h e p o s s i b i l i t y o f s u p e r - c o o l i n g of t h e w a t e r ;

( b ) t h e dett?rm.lnation of t h e water t e m p e r a t u r e v s r i a t i o n s i n r e l - a t l o n t o tlme i n r e s e r v o i r s covered w i t h i c e ( i n o r d e r t o cal- c u l a t e t h e thicknes:; of t h e I c e c o v e r , the t i m ? n e c e s s a r y f o r t h e

hresk-up o f t h e i c e and t h e l e n g t h o f I1polynia" downstream o f t h e s t r u c t u r n e s ) ;

( c ) t h e d e t e r i n i n s t i o n of t h e w a t e r t e n p * > r a t ~ r e v a r i a t i o n s i n r i v e r s and caizals d u r i n g t h e x i n t e r and pre-winter s e a s o n s ;

( d ) t h e detc?rmil?ation of the t e m p e r a t u r e v a r i a t i o n s i n p i p e s Ln w i n t e r (problems of p i p e f r e e z l l i g ) .

During t h e p r e - x a r y e a r s (1931-1941), G.I.I. Rernsrdsltcii

,

V.K.

Makl~aveev e t s l . ( All-U~ilon S c l e n t i f i c Research I n s t i t u t e of Hydro-Engineering) d c v a l o p e d methods of calculating t h e a v e r a g e t e m p - r a t u r e o f t h e w a t e r a s a f u n c t l o n o f t h e d e p t h I n open

r e s e r v o i r s w i t h o u t i c e c o v e r s and zls:, i n r e s e ~ ~ v o i r s cov(3red w i t h

i c e and i n r i v e r s .. These problems have b e e n s o l v e d b y t h e I n t ~ ~ a - t i o n of ti-Ae d l f f ? r e ! i t l . a l e q u a t i o n s o f t h e t h e r m a l b a l a n c e s h e e t .

F o r ice-covered r b e s e r v o i r s , a n a l y t i c a l s o l u t i o n s were g i v e n b y A.G. Kolesnlkov (USSR Academy of S c i e n c e s ) . I n p r a c t i c e t h e

e n y l n e e r s u s e rn2thods based on approximate c a l c u l a t i o n s which were 3 e v i s e d by B.N. Bibikov (vWIIG) and K . I . B o s s i n s k i i ( G i d r o p r o e k t ) a n 3 t h e y t a k e i n t o a c c o u n t t h e i n f l u e n c e of t h e bottom on t h e w a t e r temperature.

With an i c e - c o v e r i t w a s recommended t h a t a s t a b i l i z e d tern-

p e r a t u r e b e c a l c u l a t e d u s i n g a n a n a l y t i c a l method. T h i s method c o n s l . s t s i n r e d u c i n g t h e problem of t h e t e m p e r a t u r e d i s t r i b u t i o n a s a f u n c t i o n o f t h e d e p t h and l e n g t h o f waterways t o t h e problem of t h e d e t e r m i n a t i o n of a t e m p e r s t u r e f i e l d i n a s o l i d body ( F o u r i e r f s probllsrn)

.

Much h a s been p u b l i s h e d c o n c e r n i n g t h e c a l c u l a t i o n of ~ a t e r l v a y ~ w i t h o u t I c e - c o v e r s , e s p e c i a l l y i n t h e l a s t f e w y e a r s . P u b l i c a t l o n s by All-Union S c i e n t i f i c Re s e a r c h I n s t i t u t e of H y d r o - E n g i n e e r i w , G i d r o p r o e k t and t h e Pow?r I n s t i t u t e of t h e Academy o f S c i e n c e s of t h e Kazakh S o v i e t S o c i a l i s t Republic ]nay be c i t e d .

During t h e y s a r s 1351-1954 D.N. Bibikov ( V N I I G ) s t u d i e d the

problem of t h e t h e r m a l regime of t h e waterways c o i ~ t a l n i n g f r a z i l i c e b o t h w i t h and w i t h o u t anchor ice. I n s p i t e of t h e complexity of t h e phenomenon t h e a u t h o r was s u c c e s s f u l i n p r o p o s i n g some

r a t h e r simple a n a l y t i c a l r e l a t i o n s h i p s by which i t was p o s s 3 b l e t o

c a l c u l a t e a s t a b i l i z e d w a t e r t e m p e r a t u r e d i s t r i b u t i o n a s a f u n c t i o n of t h e d e p t h f o r b o t h a supercooled and a n o n - s u ~ e r c o o l e d w a t e r

c u r r e n t , t a k i n g i n t o c o n s i d e r a t i o n t h e h e a t due t o h y d r a u l i c l o s s e s . I n c o n c l u s i c n , i t would b e w e l l t o c i t e a s t u d y on t h e a v e r a g e t e m p e r a t u r e of waterways i n t h e p r e s e n c e of f r a z l l I c e which was p r e p a r e d i n 1955 by A.Zh. Zhulaev under t h e d i r e c t i o n of

V.P. Zakharov ( t h e Power I n s t i t u t e of t h e Academy of S c i e n c e s , Kazakh S ~ v l z t Socialist B e p u b l i c ) .

I c e on R i v e r s . P e s e r v o i r s and ?daterwsvs

I c e c o n d l t l o n s have been s t u d i e d i n . t h e USSR i n connection

b r i t h t h e b u i l d i n g of hydro-engineering s t r u c t u r e s because d u r i ~ ~ g t h e

buil-ding of the f l r s t , h y d r o - e l e c t r i c p l m t ( ~ o l k h o v s k s . y a )

,

v a r l o u s w i n t e r d i f f i c u l t i e s were encountered such as accumulation of f r a z l l i c y i n t h e end zone of t h e beckwater c u r v e s , f r e e z l n g of t h e

t r s s h r a c k s , e t c . A t t h e i n s t l g a t l o n of V.E. Timonov, a group of i c e engineers was formed I n 1930 a t Gos. I n s t . Sooruzhenii. L a t e r , i n 1931, tihis ,g-oup was a t t a c h e d t o t h e Scientific I n s t i t u t e of I I y d r o - E n ~ i n e e r l n g Research ( N I I G )

,

a new branch of t h e Power

Comn~lsslon. V.E. Tlmonov worked o u t a prograime f o r t h 5 establish-

ment of I c e e n g l n e e r l n g i n t h e U S S R . T h e main alms of t h i s

propamme were us follows: The development o f 1-ellable methods of

s tudyiny f'reez i n g phenomena, t h e reproduc t l o n o f n a t l ~ r a l f r e e z i n g phenomena on s c a l e models and t h e g e n e r i ~ l l z a t i o n of t h e r e s u l t s obt:%ined.

The study of f r e e z i n g phenomena i n t h e r i v e r s and I n t h e t a l l r a c e s of h y d r o - z l e c t r l c p l a n t s was steppe? u p w i t h the development of h y d r o - e l e c t r i c c o n s t r u c t i o n . I t was c s r r i s d o u t i n d e s i 3 and

b u i l d i n g bur2aux (Lenzidep, Mosgldep, Gidroyl-oekt, e t c . ) a s w e l l a s i n t h e C e n t r a l I n s t l t u t e of F o r ~ t c a s t i n g , t h e S t a t e Hydrol.ogica1 I v s t l t u t e ( G G I ) and by V N I I G . Our I n s t l t u t e , V N I I G , was asked t o cfi~lduct laborat;o~-y t e s t s , t o make c o m ~ : ~ r i s o n s and t o g e n e r a l i z e

t h ? d a t a obtained i n the f i e l d , u s i n g a l s o t h e r e s u l t s o b t a i n e d i n f o r e l ! g c o u n t i r e s so a s t o work o u t a s e r i e s of specifications f o r

forec:~;tin;;. thc :.!Inter reglv-2 of t h e hydro-elec t r i c p l a n t s .

'.!e could c i t e f o r example t h e experimental work done on t h e V o l p , t h e Obi, the I r t y s h , t h e Kama, the Volkhov, t h e S v i r , t h e Ylemiin and t h e I)aumva r l v e r s by "Crldroenergoproekt" s o a s t o study t h e f r z e z i n g p r o c e s s e s vrhlcli t a k e p l a c e on t h e r i v e r s under n a t u r a l

A s a n example of t h e s t u d y of t h e i c e regime i n t h e f o r e b a y s o f h y d r o - e l e c t r i c p l a n t s a l r e a d y b u i l t , we may mention t h e s t u d i e s made by Lengidep ( L e n i n g r a d Hydro-En.gineering De-pt.), t h e Kegumsk p l a n t , G i d r o p r o e k t ( I v a n t l < o v s k i i r e s e r v o i r ) and by V N I I Z (Volkhovsk, S v i r , C h i r c h l k , Dnieprovsk, MolotOvsk, Narva, e t c . )

.

A s e x p e r i e n c e was a c q u i r e d i n overcornl.ng t h e d i f f i c u l t i e s due t o i c e i n t h e newly b u i l t h y d r o - e l e c t r i c p l z l l t s , s t u d i e s were

p u b l i s h ~ d which made p o s s i b l e a classification o f t y p i c a l i c e phenomena. These s t u d i e s g i v e a t h e o r e t l c , a l a n a l y s i s of a few of t h e s e r,he~iomena and sclme p r a c t , i c a l recorn~nendaticns to t h e d e s i g n e r s

and b c i l d e r s of h y d r o - e l e c t r i c p l a n t s . A s a n example, t h e f o l l o v i i n g s t u d i e s can be c l t e d : "Plnrinine; t h e i c e regime o f l o w h e a d , run-of- r i v e r h y d r o - e l e c t r i c p l a n t s " by N.G-. G i r i l l o v i c k ~ ( v N I I G ) ; " P r i n c i p a l

i c e p r o c e s s e s and g l a c i a l . complexes", e.nd "Ch1;tf means of c o u n t e r - acl;lng t h e d i f f i c . u l . t i e s due t;o i c e i n mount,win s t r e a m s " by A.M.

E s t i f e e v (VNIIC;) ; "Th2 s t r u g g l e a g a i n s t i c z Jams on the Svl.rV by F . I . F y d i n , and rnany o t h e r s .

On t h e b a s i s of t h e work done, i t h a s become p o s s i b l e ( 1 9 3 9 ) t o pub1 l s h "Suggested t e c h n i c a l s p e c i f i c a t i o n s f o r h y d r o t h e r m a l c a l c u l a t i o n i n d e s i s i n g h y d r a u l i c viorks

,

a.nd means of c o m b a t t i n g t h e d i f f i c u l t i e s due t o i c e i n h y d r o - e l e c t r i c i n s t a l l . a t i o n s

(v~:IIG)". T k i s work d . e a l s n?ainly w i t h t h e f o r e c a s t of t h e i c e r e c i n e i n t h e planned h y d r o - e l e c t r i c s t r u c t u r e s .

During t h e e l a b o r a t i o n o f t e c h n i c a l s p e c i f i c a t i o n s , works by

f 01-eign s c i e n t i s t s havs. b e e n s t u d i e d and c r i t i c a l l y a n a l y z e d . These works were by Messrs. B a r n e s , Devlc

,

Dobrovolsky, King, S t e p h a n , Te tcy-Tamour and o t h e r s .

N o t sll t h e q u e s t i o n s c o n c e r n i n g t h e i c e regime o f t h e hydro- e l e c t r i c p l a n t s a r e d e a l t w i t h i n t h e t e c h n i c a l s p e c i f i c z t i o f i s . One o f t h e s e i s t,he q u e s t i o n r e l a t i n g t o t h e f o r m a t i o n of i c e jams

i n t h e zone of backwater c u r v e of t h e r s s e r v o i r , t h e i r movement and d e s t r u c t i o n . L'uring t h e y e a r s 1938

-

1940, G i d r o p r o e k t made some t e s t s orz i c e j m s i n t h e I v a n k o v s k i i r e s e r v o i r on t h e Volsra. r i v e r .

The a n a l y s i s of t h e phen0rner.a o b s e r v e d i s t o be found. I n t h e f o l l o w i n g s t u d y l ' l d l n t e r regl.me o f r e s e r v o i r s and c a n a l s H by

S.M. K r i t s k y , M.F. Nenl<ell, V.V. Mak~ilov,

K.M.

R o s s i n s k i i and A . S .

Semikolenov. The q u e s t i o n s of t h e i c e regime and of t b e measures t a k e n a g a i n s t w i n t e r d i f f i c u l t i e s are d e a l t w i t h i n t h e book by D.FJ. Ribikov and N.N. Petrunichev e n t i t l e d N D i f f i c u l t i e s due t o i c e

i n h y d r o - e l e c t r i c power s t a t i o n s ( 1 9 5 0 ) " , a s w e l l a s i n t h e com- p i l a t i o n "Thernio-glac i a l problems i n hydro-clec t r i c power s t a t i o n s

(1954)". I n addition, d u r i n g t h e pos t-war y e a r s , many s t u d i e s were made on p a r t i c u l a r problems of i c e c o n d i t i o n s . Some of t h e f i e l d s covered a r e :

S t u d i e s o f f r a z i l i c e and i t s a c c u m u l a t i , ~ ~ .

V.P.

Eerdennikov,

V.A. Rin~sha ( S t a t e Hydrological I n s t i t u t e ), V. V. P i o t r o v i c h ,

O.P.

Chizhov ( C e n t r a l I n s t i t u t e of orec casting), P . I . Maksunov (Academy of Sciences of t h e Uzbek S o v i e t S o c i a l i s t ~ e p u b l l c ) , N . S .

Makerov ( I n s t i t u t e of C i v i l Engineers, K o v o s i b i r s k ) , M . I . Fedorov ( A r c t i c I n s t i t u t e ) , I . A . V a s i l i s k o v , I.L. G o t l i b , E.E. Zaimin (Gidroenergoproekt), V.P. Zakharov, e t c .

S t u d i e s on 1c.e jams. L.C. Shuliakovski ( C e n t r a l I n s t i t u t e of F o r ~ c a s t i n g ) , P.N. Orlov (Academy of F l u v i a l rans sport), A.A.

Rezuglov (Hydro-meteorological S e r v i c e of t h e S o v i e t S o c i a l i s t Republic o f L i t h u e i ~ i a ) ; V N I I G ; r s s e a r c h branches of Plosgidep, Lengidep, e t c

.

P r o t e c t i v e measures a ~ a i n s t i c e . Soya. Vartazarov; V N I I G e t c .

I t i s t o be noted t h a t some problems of t h e i c e regime a r e i n - s u f f i c i e n t l y stu-died because of t h e complexity of t h e f i e l d study of t h e phenomena. Among them we may mention, f o r example, t h e con- d i t i o n s of formation and d e s t r u c t i o n o f i c e jams i n t h e a r e a n e a r t h e end of t h e backwater curve of r e s e r v o i r s , and i n p a r t i c u l a r t h e i c e regime i n a t a i l r a c e i n r e l a t i c n t o a d a i l y r e g u l a t i o n .

The S c i e n t i f i c I n s t i t u t e of Hydrotechnical Research made some s c a l e model s t u d i e s of t h e i c e p r o c e s s e s which a r e f i r s t a t t e m p t s t o s o l v e a very complex and d i f f i c u l t problem.

Metkods of Overcon~ina th e D i f f i c u l t i e s Caused .-bv I c e During t h e Construction zn? t h e Operation of Hydro-Electric Plan t.s Coxtrol of i c e processes i n t h e forebay and t a i l r a c e of hyrlro- e l e c t r i c s t a t i o n s d u r i n g t h e f a l l and spi-lnr i c e runs

I n o r d e r t o f a c i l i t a t e t h e evacuation of i c e through hydraaulic s t r u c t u r e s and. i n o r d e r t o improve t h e o p e r a t i o n of t h e l a t t e r

d u r i n g t h e w i n t e r season, A . K . E s t i f e e v ( V N I I G )

,

V.P. Zakharov (Acad.emy of Sclences of t h ? Kazakh Soviet S o c i a l i s t Republic) and. oth.sras have developed various means of c c n t r o l l l n g t h e i c e process- es i n t h e waterwzys. They have, i n p a r t i c u l a r :

( a ) d r a f t e d recommendations f o r t h e simultar,eous use o f t h e rssimes of t h e f r a z i l passage and i t s accu!nulstion d u r i n g t h e

autumn f r e e z i n g (methods a r e o u t l i n e d f o r d e t e r a i n i n g t h e volume of f r a z i l which m u s t b e accurn~~I.~.ted i n t h e f'orebay and t h ~ t which must be t r a n s p o r t e d t o t h e t a i l r a c e ) ;

( b ) developed v a r i o u s means of re,gula.ting t h e autumn and s p r i n g i c e f r e e z i n g and break-ups s o a s t o r e t a i n the i c e i n s u i t - a b l e l o c a t i o n s and t o remove i t more thoroughly from t h e inappropri- a t e p l a c e s ;

( c ) s t u d i e d t h e q u e s t i o n of r e g u l a t i n g t h e d i s c h a r g e of t h e water through o p e r a t i n g p l a n t s 1oca.ted upstream of t h e new s i t e s under c o n s t r u c t i o n i n o r d e r t o o b t a i n a favourable i c e regime i n t h e c o n s t r u c t i o n area.

Evacuation of the i c e througyh h y d r a u l i c s t r u c t u r e s d u r i n a t h e c o n s t r u c t i o n and o p e r a t i o n periods

Formerly, an i c e evacuation f r o n t occupying t h r e e f i f t h s of t h e t o t z l width of the r i v e r was considered adequate.

A f t e r znalyzing d a t a obtained through t h e study of i c e evacua- t i o n a t a few h y d r o - c l e c t r i c p l a n t s ( ~ g l i c l ~ s k a y a , Shcherbakovskaya, Kegumskaya, Ivznkovsk~.ya, e t c . ) A.M. E s t i f e e v ( ~ 1 1 1 1 ~ ) e s t a b l i s h e d

t h e r e l a t i c n s h i p e x i s t i n g between t h e head on a weir ( t h i c k n e s s of t h e nappe) and t h e width of t h e evacuation f r o n t of t h e i c e ( a t t h e beginning of break-up) t h e r e l a t i o n can be expressed i n t h e

f 01 lowing way :

where: B

-

t h e width

of

t h e d i s c h a r g i n g f r o n t ; H

-

t h e head on t h e w e i r and,

a

and n

-

c o e f f i c i e n t s o b t a i n e d by a n a l y z i n g t h e r e s u l t s of f i e l d t e s t s .

The same r e l a t i o n s h i p was o b t a i n e d by

K.N.

Korzhavin ( T r a n s p o r t Power I n s t i t u t e , Novosibirsk) d u r i n g a s t u d y of t h e q u e s t i o n of i c e e v a c u a t i o n through t h e openings between t h e p i e r s of a b r i d g e .

I n connection with t h e problem of i c e e v a c u a t i o n through hy- d r a u l i c s t r u c t u r e s , E s t i f e e v developed ways of changing t h e regimes of waterways s o a s t o f a c i l i t a t e t h e e v a c u a t i o n of i c e : he r e - commended r e t a i n i n g of t h e i c e cover i n t h e upper bay (once t h e r i v e r s t a r t s flowing) f o r some time: d u r i n g t h i s time t h e s t r e n g t h of t h e i c e weakens. To determine t h e s t r e n g t h of t h e i c e cover i n s p r i n g , V N I I G recommends t h e f o l l o w i n g s p e c i a l formula:

a

compr = 200

-

z [ ( x ~ )

-

301t/m0,

where:

a

_compr

-

t h e t r a n s i t o r y compressive s t r e n g t h of t h e i c e ;

28

-

t h e sum of a i r temperatures above

zero

c e n t i g r a d e from t h e t i m e t h a t t h e temperature r i s e s above z e r o c e n t i g r a d e ( i n s p r i n g ) u n t i l t h e time o f d e t e r m i n i n g 0 compr R e t e n t i o n of t h e i c e i n t h e f o r e b a y w i l l c o n s i d e r a b l y d e c r e a s e t h e i c e s t r e n g t h and w i l l f a c i l i t a t e t h e e v a c u a t i o n of t h e i c e through t h e hydro-engineering s t r u c t u r e s . S . V . T i t o v s t u d i e d t h e q u e s t i o n of i c e e v a c u a t i o n through bottom o u t l e t s and e s t a b l i s h e d a r e l a t i o n s h i p between t h e c r i t i c a l flow when t h e i c e i s drawn i n t o an opening and t h e p o s i t i o n of t h i s opening i n r e l a t i o n t o t h e w a t e r l e v e l

Qcr

where: Qcr

-

t h e s p e c i f i c flow of t h e water causing i c e t o be drawn i n t o an opening, m3/sec.

-

t h e head of water above the opening,

m.

Ho

-

t h e thickness of the water l a y e r below the opening, m.

I1

-

t h e head of water i n f r o n t of the entrance t o t h e opening, m.

P r o t e c t i n g t h e m e t a l l i c p a r t s of the p l a n t s a g a i n s t f r e e z i n q ( t r a s h r a o k s . g a t e s . penstocks)

The f r e e z i n g of trashracks i n the water i n t a k e s i s one of the d i f f i ~ u l t l e s caused by i c e . I t i s a very common d i f f i c u l t y charac- t e r i s t i c of hydro-electric p l a n t s . This d i f f i c u l t y increases the head l o s s e s i n the racks, reduces the discharge through the turbines and sometimes c u t s the water inflow e n t i r e l y off.

A t present the most common and the most r e l i a b l e means of pre- venting the f r e e z i n g of the intake trashracks i s b y h e a t i n g the bars. It i s reasoned t h a t i f the surface of t h e b a r s I s heated t o a temperature s l i g h t l y above t h e f r e e z i n g temperature of water, t h e bars w i l l not be iced over.

In most cases t h e e l e c t r i c c u r r e n t i s passed d i r e c t l y through the bars. I n some cases the bars a r e hollow, and then they a r e heated from within ( t h e heat i s brought t o the racks and i s forced through the b a r s , o r e l s e h e a t e r s can be i n s t a l l e d i n the b a r s ) . I n order t o determine the power necessary t o h e a t t h e racks t h e following empirical formulas a r e suggested:

f o r t r a s h r a c k s with b a r s of c i r c u l a r s e c t i o n :

where d i s the diameter of a b z r , i n meters;

twater i s t h e water temperature i n degrees Centigrade ;

V i s t h e water v e l o c i t y , m/sec.

L a t e r , i n 1955, a new h e a t i n g method was suggested b y V N I I G ( A . I . Pekhovich and S.M. ~ l e i n i k o v ) f o r t h e bars. This method was developed i n o r d e r t o conserve h e a t i n g energy. I n essence, i t con- s i s t s i n h e a t i n g t h e f r o n t p a r t of t h e b a r s on t h e upstream s i d e , This method was used by "Gidroproekt" ( E . A . Sarkisov and I . M .

~ h e r p a n o v ) i n t h e i n d u c t i o n h e a t i n g of t h e t r n s h r a c k s a t t h e

Kuibyshev p l a n t . It can a l s o be pointed out t h a t i n o r d e r t o pre- vent f r e e z i n g , various hydrophobic coatln,zs can be used. This h a s been suggested by V.A. A l t b ~ r g .

V.V. P i o t r o v i c h ( S t a t e Hydrological I n s t i t u t e ) made t h e f i r s t l a b o r a t o r y t e s t s . The study under f i e l d c o n d i t i o n s of t h e p r o t e c t -

ing e f f e c t s of various c o a t i n g s was made a t V N I I G i n 1953. I t was revealed t h a t mixtures of bitumen and p a r a f f i n and of rubber and o t h e r substances g r e a t l y reduced t h e f r e e z i n g of t h e t r a s h r a c k s

( b u t d i d n o t prevent i t completely). Organic s i l i c o n c o a t i n g s have r e c e n t l y been proposed a s a n t i f r e e z e s (1.Q. Voronkov and B.N.

Dolgov).

Heating i s used f o r p r o t e c t i n g t h e s a t e s of dams and l o c k s and e s p e c i a l l y t o prevent t h e i r being f r o z e n t o t h e embedded p a r t s .

I n the l a s t few y e a r s , V N I I G i n c o l l a b o r a t i o n with n G i d r o s t a l p r o e k t w h a s developed methods of thermal c a l c u l a t i o n f o r h e a t i n g purposes and has conducted c o r r e spondlng l a b o r a t o r y and f i e l d t e s t s , There

i s a p e a t v a r i e t y of h e a t i n g methods. For example, i n t h e c a s e of embedded m e t a l l i c s t r u c t u r e s h e a t i n g i s achieved by t h e d i r e c t

j a s s a s e of e l e c t r i c c u r r e n t through t h e s e s t r u c t u r e s , o r by i n s e r t - i n g tubes i n s i d e t h e c o n c r e t e along t h e compacting l i n e ; h o t mineral o i l i s then made t o pass through t h e s e tubes.

I c e P r e s s u r e A g a i n s t S t r u c t u r e s

-.

We d i s t i n g u i s h between t h e t h r u s t caused by t h e t h e r m a l expan- s i o n o f t h e i c e c c v e r ( s t a t i c p r e s s u r e ) and a dynamic p r e s s u r e

caused by t h e impact o f f l o a t i n g i c e a g a i n s t a s t r u c t u r e . Many

s t u d i l s s by S o v i e t s c i e n t i s t s d e a l w i t h t h i s q u e s t i o n o f i c e p r e s s u r e . I n t h e S t a t e s p e c i f i c a t i c n s of t h e USSR i t i s recommended t h a t t h e v a l u e of t h e s t a t i c p r e s s u r e be determined by Royen's formula. I n t h i s f o r m u l a , however, t h e r e i s a n e r r o r . Proskuryakov h a s proved t h a t when t h e R o y e n t s f o r m u l a i s c o r r e c t e d t h e r e s u l t s ob-

tainc;.rl are much s m a l l e r ( u p t o t h r e e t i m e s ) . C o n s i d e r i n g i c e as a v i s c o u s s u b s t a n c e , u s i n g Navier-Stokes e q u a t i o n and t a k i n g i n t o c o n s i d e r a t i o n t h e e l a s t i c l i m i t o f t h e i c e , Proskuryakov o b t a i n e d a n e q u a t i o n t o d e f i n e t h e v a l u e of t h 2 s t a t i c i c e t h r u s t .

L a b o r a t o r y s t u d i e s on t h e s t a t i c t h r u s t were made a t V N I I G u n d e r

A.i!. Y s t i f e e v . The c o n c l u s i o n from t h e s e s t u d i e s i s t h a t i n t h e g i v e n c o n d i t i o n s t h e a c t u a l t h r u s t i s s m a l l e r t h a n t h e c a l c u l a t e d t h r u s t a c c o r d i n ? t o t h e c o r r e c t e d R o y e n t s formula o r a c c o r d i n g t o

Proskur,yakovl s

.

The a t t e n t i o n of t h e i n v e s t i g a t o r s i s drawn i n most c a s e s t o

t h e e f f e c t of t h e dynamic p r e s s u r e . A block o f i c e may s t r i k e e i t h e r a very wide o b s t a c l e l i k e n w a l l , o r a narrow one l i k e a b r i d g e p i e r . I n t h e c a s e o f a w a l l i t i s g e n 2 r a l l y supposed t h a t i t i s t h e p o i n t e d s i d e o f t h e i c e b l o c k which h i t s t h e o b s t a c l e . Then t h e e n e r g y of t h i s i c e b l o c k coming down i n t h e s t r e a m i s p a r t l y s p e n t i n b r e a k i n g a p a r t of t h e b l o c k (N.M. Shchapov, P . A .

Kuznztsov)

.

O t h e r i n v e s t i g a t o r s (2.V. Zylev, P.A

.

Kuzne t s o v and o t h e r s ) t h i n k t h a t t h i s method can b e used t o c a l c u l a t e t h e f o r c e o f t h e impact when i t i s t h e s t r a i g h t edge o f t h e i c e 'olock which h i t s t h e v e r t i c a l i c e - b r e a k e r . Many i n v e s t i g a t o r s ( A . N . Kornarovskii,

S o u r i n and o t h e r s ) e s t i m a t e t h a t t h e f o r c e "Pn of an i c e b l o c k h i t t i n g a v e r t i c s l i c e - b r e a k e r c a n n o t exceed t h e v a l u 3 o f t h e

s t a t i c p r e s s u r e which c a u s e s t h e d e s t r u c t i o n of t h e i c e ; t h a t i s t o s a y w e have a formula of t h e f o l l o w i n s t y p e :

where a i s t h e t r a n s i t o r y c o ~ n p r e s s i v e s t r e n ~ t h

of

t h e i c e ; F i s t h e a r e a of c o n t a c t of t h e i c e w i t h t h e i c e - b r e a k e r ; n i s a c o e f f i c i e n t t a k i n g i n t o a c c o u n t t h e shape ( i n p l a n ) o f t h e i c e - b r e a k e r , t h e i m p e r f e c t i o n of t h e c o n t a c t and t h e i n f l u e n c e o f t h e speed of t h e i c e b l o c k ( l o c a l c r u s h i x e f f e c t ) ( n = 0.4

-

0.7).

To d e t s r m i n e t h e f o r c e w i t h which a n i c e b l o c k comes i n t o con- t a c t w i t h a n o b s t a c l e , i t i s more i m p o r t a n t t o know t h e c a l c u l a t e d v a l u s o f t h e t r a n s i t o r y s t r e n g t h of t h e i c e t h a n t h e s t r u c t u r e o f t h e f o r m u l a , which d o c s n o t r e p r e s e n t t h e pheno~nznon w i t h g r e a t a c c u r a c y . Various 1 n v e s t i ~ ; a t o r s recommend t a k i n g t h i s v a l u e from w i t h i n t h e f o l l o w i n g l i m i t s :

Among t h e f o r m u l a s which were proposed f o r c a l c u l a t i n g t h e

impact f o r c e of an i c e b l o c k a g a i n s t a n i c e - b r e a k e r , t h e formula by B.V. Zylev should b e p o i n t e d o u t . T h i s formula was o b t a i n e d by

s t u d y i n g t h e s t a t e of s t r e s s o f a h a l f - s l a b p l a c e d on a n e l a s t i c f o u n d a t i o n under t h e i n f l u e n c e of t h e i n c l i n e d f o r c e c o n c e n t r a t e d a t t h e edge.

Among t h e e x p e r i m e n t a l s t u d i e s which have been made on t h e d e t s r r n i n a t i o n o f t h e dynamic p r e s s u r e of t h e i c e , t h e l a b o r a t o r y

s t u d i e s made a t V N I I G ( A . I . Pekhovich and G.S. S h a d r i n ) and t h e

V N I I G f i e l d s t u d i e s ( A . 1 . Gainayunov, K . P . Korzhavin) should be

mentioned.

We must a d m i t , however, t h a t from a t h e o r e t i c a l and experiment-

a l p o i n t o f view, t h e r e s e a r c h on t h e dynamic e f f e c t of t h e i c e on h y d r a u l i c s t r u c t u r e s i s s t i l l incomplete.

Use o f R e f r i a e r a . t i o n f o r B u i l d i n g P u r p o s e s

The method of a r t i f i c i a l f r e e z i n g of s o i l s i s w i d e l y used i n t h e USSR f o r t h e b u i l d i n g of c i v i l and i n e u s t r i a l s t r u c t u r e s . With t h i s method, i t i s p o s s i b l e t o b u i l d s t a b l e , an3 w a t e r p r o o f c o f f e r -

under d l f f l c u l t hydro-geological c o n d i t i o n s (e.g. t h e b o r i n g of

mine s h s f t s and subway t u n n e l s ) . Cofferdams e r e c t e d f o r t h e con- s t r u c t i o n o f h y d r a u l i c s t r u c t u r e s have p a r t i c u l a r l y l a r g e dimensions and they a r e used g e n e r a l l y a ? unwatering d e v i c e s . This f a c t p r e -

v e n t s t h e d i r e c t , use of experiencn a c q u i r e d I n t h e b u i l d i t ~ e ; of f r o z - en e a r t h cofferdams on c i v i l e n g i n e e r i n s p r o j 5 c t s . Thc f r e e z i n p of

t h e s o i l i s more d i f f i c u l t i n the presence of a streclm of i n f i l t r a t - i n g water. It was n e c e s s a r y t o undertake s p e c i a l t h e o r e t i c a l and experimental s t u d i e s so a s t o develop methods of thermotechnical c a l c u l a t i o n f o r t h e b u i l d l n ~ o f cofferdams made with f r o z e n e a r t h i n perm3able ground. ble should t h e r e f o r e mention t h e s t u d i e s made by A . I . Charnyl who formulated mathematically t h e p h y s i c a l p r o c e s s e s which t a k s p l a c e d u r i n e t h e f r e e z i n g o f permeable s o i l s and who

recommended c a l c u l a t i o n formulas. Many t h e o r e t i c a l and e x p e r i m e n t a l s t u d i e s were made a t V N I I G under t h e d i r e c t i o n of B.V. Proskuryakov. I n the f i r s t p l a c e , he solved t h e problem of t h e rnaxirnum d i a m e t e r which a c y l i n d e r of f r o z e n e a r t h may have around an i s o l a t e d h o l e i n p ~ r m e a b l e ground. S u b s ~ q u e n t s t u d i e s were devoted t o t h e solu- t i o n of t h e problem of J o i n i n g up t h e i s o l a t e d c y l i n d e r s made of f r o z e n e a r t h so a s t o form an u n i n t e r r u p t e d w a l l and then f r e e z i n g t h i s w a l l ( A .I. P e k h ~ v i c h and G.S. Shadrin)

.

These t h e o r e t i c a l works as w e l l a s s p e c i a l l a b o r a t o r y s t u d i e s were used f o r f r e e z i n g

t h e s o i l d u r i n g t h e b u i l d i n g of t h e Gorkhovska p l a n t and o t h e r s t r u c t u r e s . We should a l s o mention a few s u c g e s t l o n s made by K . V .

Sevenard, Chief Enzineer a t Gorkovgesstroi. Two f r o z e n - s a r t h

c o f f e r d ~ l n s were s u c c e s s f u l l y b u i l t t h e r e under h i s s u p e r v i s i o n i n complex g e c l o g i c a l c o n d i t i o n s . Although cofferdams I n f r o z e n

e a r t h a r e very expensive, t h i s method of c o n s t r u c t i o n i s sometimes the only r e l i a b l e one.

Flans h a w now been drawn f o r a f r o z e n - e a r t h cofferdam t o be b u i l t zit t h e h y d r o - e l e c t r i c p l a n t st Kaunas. We propose t o use t h i s method of s o i l f r e e z i n g t o b u i l d o t h e r h y d r o - e l e c t r i c p l a n t s

Study of t h e F h y s i c a l C0nstan.s of I c e

To s o l v e i c e problems i t was n e c e s s a r y t o d e f i n e t h e v a r i o u s p r o p e r t i e s of i c e

-

mechanical, thermal, e l e c t r i c , o p t i c a l and o t h e r s . The p r o p e r t i e s of i c e a r e c h a r a c t e r i z e d n u m e r i c a l l y b y

c e r t a i n p h y s i c a l c o n s t a n t s . B.P. Veinberg, i n h i s s u b s t a n t l a l s t u d y e n t i t l e d "The I c e " has given a d e t a i l e d review of a l l t h e work done on t h i s q u e s t i o n up t o 1940. I n t h i s r e p o r t we mention o n l y a few s t u d i e s , c h i e f l y t h o s e which concern t h e above-mentioned q u e s t i o n s . A t V N I I G , B.V. Proskuryakov, D.N. Bibikov,

A.I.

Pekhovich and I . N . Sokolov have determined t h e c r y s t a l l i z a t i o n speeds of supercooled water, t h e c o e f f i c i e n t s of h e a t t r a n s m i s s i o n from water t o i c e , t h e p o r o s i t y and t r a n s i t o r y s t r e n g t h of f r a z i l i c e and of anchor i c e , t h e h y d r a u l i c c h a r a c t e r i s t i c s of f r a z i l i c e , t h e albedo of i c e , e t c .

Among the s t u d i e s made a t CX3I ( V . A . Ryrncha, V.P. Berdennikov,

R.V. Dgnchenko and o t h e r s ) t h e s t u d i e s on t h e bonding s t r e n g t h of i c e w i t h v a r i o u s b o d i e s s u b j e c t e d t o f r o s t , t h e v i s c o s i t y c o e f f i - c i e n t , t h e e l a s t i c i t y modulus of i c e and t h e f r e e z i n g temperature of w a t e r s w i t h v a r i o u s s a l t c o n c e n t r a t i o n s a r e t o be noted.

The experimental s t u d i e s of t h e mechanical and p h y s i c a l proper- t i e s of i c e were made by K.N. Korzhavin ( N o v o s i b i r s k ) , B.D.

Kartashkin

(Z.A.Q.I.)

and F.F. Vitman, N.P. Shandrinkov and V.V.

Lavrov ( A r c t i c I n s t i t u t e ) . I n t h e l a s t few y e a r s , A.G. Tkachev ( L e n i n p a d Cold I n s t i t u t e ) d e f l n e d t h e h e a t e x c h a n e c o e f f i c i e n t s on t h e i c e s u r f a c e e i t h e r i n t h e f r e e z i n g o r u n f r e e z i n g s t a g e .

Conclusion

( Immediate problems)

The r e s u l t s of t h e above-described s t u d i e s show t h a t a l l i c e problems have n o t y e t been t a c k l e d . Some o f t h e s e problems have n o t y e t been t a c k l e d . Some of t h e s e problems have n o t been s t u d i e d i n

d . e t a i 1 up t o t h e p r e s e n t time, and have n o t been thoroughly analyze? on a.ccount of t h e i r complexity.

Let us revlev1 b r i e f l y t h e main problems now f a c i n g t h e s c i e n - t i s t s and. e n g i n e e r s engaged i n solvl-ng t h e i c e problems.

A s r e g r r d s s t u d i e s of tho thermal and i c e regimes of waterways

and of r e s e r v o i r s , i t i s n e c e s s a r y , f i r s t of a l l , t o develop methods of f o r e c a s t i n g t h e thermzl and i c e regimes of deep o r shallow

r e s e r v o i r s . This i s necessary because t h e rnetk~ods used a t t h e p r e s e n t time f o r t h e thermal c a l c u l a t i o n of r e s e r v o i r s can a l s o be used f o r r a t h e r sha.110~ r e s e r v o i r s up t o a w a t e r temperature of f o u r degrees. \dhen ana.lyzing t h e thermal phenomena i n very deep r e s e r v o i r s , i t i s n e c e s s a r y t o i n t r o d u c e t h e n o t i o n of v e r t i c a l h e a t t r a n s f e r by f r e s c c n v e c t i o n :>ad t o f i n d t h e l i m i t s w i t h i n which h e a t t r a n s f e r due t o p h y s i c a l ( d i f f u s e ) t r a n s m i s s i o n can be n e g l e c t e d . The s t u d i e s made i n t h e f i e l d of t h e therma.1 regime of l a k e s , r e s e r v o i r s and forebays show t h a t i t i s impossible t o n e g l e c t i n t h e c a l c u l a t i o n s t h e very important i n f l u e n c e of the wind on t h e thermal regime of t h e water. This c o n d i t i o n c a l l s f o r a d e t a i l . e d s t u d y of t h i s very d e l i c a t e problem. To t h i s problem i s l i n k e d a l s o t h e problem r e l a t i n g t o t h e c c n d i t i o n s of formation of t h e i c e cover when t h e wind blows.

Another problem which must be s t u d i e d i n more d e t a i l c o n s i s t s i n developing methods f o r f o r e c z s t i n g t h e break-up i n r i v e r s

,

c a n a l s and r e s s r v o i r s . T h e methods used today f o r f o r e c a s t i n g t h e above- desclaibed phenomena ( f o r example t h e analogue method) a r e n o t

always adequate a-nd t h a t i s why i t i s n e c e s s a r y t o r e v e r t nlore t o a n a l y t i c a l s o l u t i o n s . An e x c e p t i o n a l complexity i n t h e t y p e s and i n t h e development of s p r i n g break-up and f a l l freeze-up

,

depending on me t.eorologica1 c o n d i t i o n s , t h e t h i c k n e s s of t h e i c e , i t s

mechanical r e s i s t a n s e , t h e v a r i 5 b l e f l o w s , t h e e f f e c t o f t h e water of m e l t i n g , make i t even more d i f f i c u l t t o o b t a i n a d e f i n i t e

a n a l y t i c a l s o l u t i o n f o r t h e f o r e c e . s t i n g of t h e break-ups and freeze-ups i n t h e waterways and of t h e c h a r a c t e r they w i l l have. I n t h e s e c a s e s , t h e problem can be solved by u s i n g s c a l e models. c i f f i c : ~ ! l t i e s w i l l a l s o be met i n t h e e s t a b l i s h m e n t of t h e d i f f e r - e n t i a l e q u a t i o n s which r e p r e s e n t t h e break-up p r o c e s s ; t h e s e

e q u a t i o n s a r e used a s a b a s i s f o r t h e c o n s t r u c t i o n of s c a l e r e l - a t i o n e q u a t i o n s .

That i s why a method of approximate study of break-up must be developed on s c a l e models. Once t h i s problem h a s been solved i t

w i l l be p o s s i b l e t o d e a l w i t h problems r e l a t i n g t o t h e e v a c u a t i o n o f t h e i c e d-uring t h e b u i l d i n g

of

h y d r o - e l e c t r i c p l a n t s . I t i s n o t enough t o study t h e regimes i n which t h e i c e i s evacuated witk,out d i f f i c u l t y ; means must be found f o r t h e e n g i n e e r t o i n f l u e n c e t h e d a t e s on which t h e break-ups w i l l begin and end anywhere a l o n g t h e r i v e r .

The q u e s t i o n of i c e jams i s a l s o l i n k e d t o t h e above-mentioned ones. T h i s problem h a s g r e a t p r a c t i c a l importance. To prove t h i s p o i n t , we can r e c a l l t h a t t h e c i t y o f Kaunas because of t h e accumu- l a t i o n of f r a z i l i c e and t h e formation of i c e jams on t h e r i v e r Neman i s f r e q u e n t l y s u b j e c t e d t o f l o o d i n g s ; tha same happens a t Dvinsk, which i s s i t u a t e d on t h e Dvina o c c i d e n t a l r i v e r , and a t o t h e r s i t e s .

F u r t h e r s t u d i e s of t h e s t a t i c p r e s s u r e of i c e should be con- cerned w i t h t h e s e t t i n g - u p of l a b o r a t o r y experiments of k ~ i d e r scope w i t h a view t o v e r i f y i n g t h e t h e o r e t i c 2 1 p a t t e r n s . I t i s a l s o n e c e s s a r y t o determine t h e i n f l u e n c e on t h e i c e p r e s s u r e o f any c r a c k s which may e x i s t i n t h e i c e c o v e r , t h e c o n f i g u r a t i o n of t h e r e s e r v o i r , t h e c h a r a c t e r of t h e banks, t h e lowering of t h e l e v e l i n t h e forebay d u r i n g o p e r a t i o n of t h e p l a n t . A s f a r as t h e dynamic p r e s s u r e i s concerned, i t i s n e c e s s a r y t o puruse t h e study o f t h e i c e s t r e n g t h d u r i n g t h e s p r i n g break-up.

The a c t u a l v a l u e s o f t h e i c e t h r u s t a g a i n s t h y d r a u l i c s t r u c - t u r e s must be determined under n a t u r a l c o n d i t i o n s with much i m -

proved a p p a r a t u s .

As f a r a s t h e r a t l o n a l l z a t i o n of t h e p l a n t o p e r a t i o n d u r i n g t h e w i n t e r i s concerned, i t i s n e c e s s a r y t o d e v e l o p methods making i t p o s s i b l e f o r a h y d r o - e l e c t r i c p l a n t t o o p e r a t e c o n t i n u o u s l y d u r l n g t h e c o l d season.

One means c o n s i s t s i n t h e development of a s u i t a b l e system f o r t h e o p e r a t i o n of a p l a n t .

Such systems must be i n v e s t i g a t e d more f u l l y i n r e l a t i o n t o t h e p a r t i c u l a r type of h y d r o - e l e c t r i c p l a n t and waterway. Thi s means t h a t I t I s necessary t o p r e p a r e recommendations a s t o when, under what c o n d i t i o n s and f o r how l o n g t h e o u t p u t of t h e p l a n t

should be v a r i e d , o r t o r e g u l a t e t h e forebay l e v e l i n o r d e r t o evacuate t h e f r u z i l i c e through t h e t u r b i n e s , o r i c e through

s t r u c t u r e s , o r e l s e t o r e t a i n t h e i c e i n t h e forebay. It i s a l s o n e c e s s a r y t o c o n s i d e r l o c a l means of p r e v e n t i n g t h e p e r t u r b a t i o n s caused by i c e . The main t r e n d of t h e s e s t u d i e s must be towards t h e e l i m i n a t i o n , a s f a r a s p o s s i b l e ( i f n o t e n t i r e l y ) of t h e use o f f r a z i l s l u i c e s and t h e r e d u c t i o n of t h e e l e c t r i c power c o s t s f o r t h e h e a t i n g o f m e t a l l i c s t r u c t u . r e s I n h y d r o - e l e c t r i c p l a n t s sub- j e c t e d t o f r e e z i n g c o n d i t i o n s . Up t o now l i t t l e a t t e n t i o n h a s been paid t o t e c h n i c a l and economical comparisons o f v a r i o u s means of combatting t h e d i f f i c u l t i e s caused by i c e . For example, whereas I t may be more l o g i c a l i n one h y d r o - e l e c t r i c p l a n t t o adopt e v a c u a t i o n of f r a z i l through t u r b i n e s by' means of i n c r e a s i n g t h e speeds i n t h e i n t a k e c a n a l , i n a n o t h e r c a s e t h i s method may n o t be p r o f i t a b l e and i t should be r e p l a c e d by e v a c u a t i o n through s p e c i a l f u n n e l s , o r perhaps t h e f r a z i l should be kept i n t h e forebay.

The d a t a given above show t h a t t o meet requirements i n b u i l d i n g and o p e r a t i n g h y d r o - e l e c t r i c p l a n t s o u r i c e e n g i n e e r s have s t i l l t o s o l v e many problems and t o c a r r y o u t many s t u d i e s . It seems t o u s t h a t t h e s u c c e s s f u l r e a l i z a t i o n o f t h i s r e s e a r c h

i s

p o s s i b l e o n l y i f we, i c e e n g i n e e r s , maintain a f r i e n d l y s p i r i t o f coopera- t i o n n o t only i n d i f f e r e n t o r g a n i z a t i o n s but a l s o i n d i f f e r e n t c o u n t r i e s .

A b b r e v i a t i o n s Used G T T I V N I I G N I I G TsIF GUGMS G G I L I IVT G C I N LPI N I V I T TsAGI S t a t e P r e s s f o r Technical and T h e o r e t i c a l L i t e r a t u r e All-Union Research I n s t i t u t e of Bydro-Engineering Research I n s t i t u t e of Hydro-Engineering

C e n t r a l Weather I n s t i t u t e

Main Adrnirlis t r a t i o n of Hydro-Meteorological S e r v i c e s S t a t e Hydrological I n s t i t u t e

Leningrad I n s t i t u t e of Water T r a n s p o r t Engineers S t a t e Oceanographic I n s t i t u t e

Leningrad P o l y t e c h n i c a l I n s t i t u t e

Novosibirsk I n s t i t u t e o f M i l i t a r y R a i l r o a d Engineers C e n t r a l Aero-Hydrodynamics I n s t i t u t e

Leningrad D i v i s i o n of t h e Research Engineering S o c i e t y of Water T r a n s p o r t ( n o t a d e f i n i t e i d e n t i f i c a t i o n ) A r c t i c Research I n s t i t u t e

R i b l i c m a p h y

I. General Pr_oblems

1. Timonov, V . 3 . O r g a n i z a t i o n of r e s e a r c h i n i c e e n g i n e e r i n g . Gldrotekh. S t r o i t e l . ( 3 ) , 1931.

2. Blbikov, D.N. and Petrunichev, N.N. Ledcvye zatrudnemlla na g i d r o s t a n t s i i a k h ( I c e t r o u b l e s a t h y d r o s t a t i o n s ) . Gosenergoizdat, Moscow-Leningrad, 1950.

3. I c e and thermal problems i n h y d r o e l e c t r i c a l e n g i n e e r i n g . Bibikov, D.N. Ed. c o l l e c t e d works. Gosenergoizdat, Moscow-Leningrad, 1954.

4. Veinberg, B.P. Led ( s v o i s t v a , vozniknwenle 1 lscheznovenie l ' d a ) I c e ( p r o p e r t i e s , formation and d i s a p p e a r a n c e ) . GTTI,

Moscow-Leningrad

,

1940.

5. K r l t s k i i , S.N. e t a l . Zimnii t e r m i c h e s k i i rezhim vodokhranl- l l s h c h , r e k I kanalov (elementy t e o r i i 1 metodiki

lnzhenernogo r a s c h e t a ) (Winter temperature regime i n r e s e r v c i r s , r i v e r s and c a n a l s ( t h e o r y and methodology i n e n g i n e e r i n g c a l c u l a t i o n s ) . Gosenergoizdat, Moscow-

Leningrad, 194'7.

6. Belokon

,

P. N. 1nzhenerna.ya g i d r a v l i k a potoka pod ledianym pokpovom ( E n g i n e e r i n s h y d r a u l i c s of w a t e r flowing under i c e ) . Gosenergoizdat, Moscow-Leningrad, 1940.

7. Bregman, G.R. and Proskuryakov, B.V. Ledlanye perepravy ( I c e c r o s s i n g s ) . Gidrometeoizdat, Moscow-Leningrad, 1948.

8. Zaikov,

B.D.

Ocherki po ozerovedenlyvl (Notes on l a k e s t u d i e s ) . Gidrorneteoizdat, Leningrad, 1955.

3. Konovalov,

I.M.,

Emel'yariov, K.S. and Orlov, P.N. Osnovy ledo- tekhnilci rechnogo t r a n s p o r t a (Fundamentals o f i c e

e n g i n e e r i n g i n r i v e r t r a n s p o r t ) . I z d . Min. recl~nogo f l o t a SSSR, Moscow-Leningrad, 1952.

10. B o g s l o v s k l i , P . A . Ledovyi rezhim t r u b o ~ r o v o d o v g i d r o s t a n t s i i (1ce c o n d i t i o n s i n penstocks of h y d r o s t a t i o n s ) .