Loads exerted on hydraulic structures by waves, ice and ships

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Loads exerted on hydraulic structures by waves, ice and ships National Research Council of Canada. Division of Building Research

CANADA INSTITUTE

FOR SCIENTIFIC AND TECHNICAL INFORMATION INSTITUT CANADI EN DE L'INFORMATION SCIENTIFIQUE ET TECHNIQUE NRC/CNR TT-1968 TECHNICAL TRANSLATION TRADUCTION TECHNIQUE

SNiP-11-57-75 CONSTRUCTION STANDARDS AND RULES PART II. DESIGN STANDARDS

CHAPTER 57

LOADS EXERTED ON HYDRAULIC STRUCTURES BY WAVES, ICE AND SHIPS MOSCOW, 1976

TRANSLATED BY/TRADUCTION DE D.A. SINCLAIR

THIS IS THE TWO HUNDRED AND THIRTY-SIXTH IN THE SERIES OF TRANSLATIONS PREPARED FOR THE DIVISION OF BUILDING RESEARCH

I _/ I "

TRADUCTION NUMERO 236 DE LA SERlE PREPAREE POUR

1\

LA DIVISION DES RECHERCHES EN BATIMENT

1+

NATIONAL RESEARCH COUNCIL OF CANADA CONSEIL NATIONAL DE RECHERCHES DU CANADA

TECHNICAL TRANSLATION 1968 TRADUCTION TECHNIQUE

SNiP-11-57-75 Construction Standards and Rules Part II. Design Standards

Chapter 57

Loads Exerted on Hydraulic Structures by Waves, Ice and Ships Moscow, 1976

Canada Institute for Scientific and Technical Information

Institut canadien de 1 'information scientifique et technique

Ottawa, Canada K1A OS2

Canada and the Soviet Union share similar geographical positions and likewise similar problems with ice loads on structures. Soviet experience in dealing with ice problems has resulted in the publication of ice codes in 1959, 1967 and now most recently in 1976. There are now efforts in Canada to revise and update existing ice codes here. It was felt that the translation of this most recent Soviet Code would be a useful contribution to Canadian engineers and code writers. Only the part on ice of a chapter in SNiP II - 57-75, which includes, as well, wave and vessel effects on hydraulic structures, has been translated and printed in this publication.

It should be pointed out, that the literature on which the Soviet Code is based is not readily available for evaluation. Therefore it is not possible to judge how applicable the recommendations are to Canadian conditions. This document should only be considered as an additional source of experience either in formulating guidelines for Canada or in assessing ice forces for particular locations in Canada.

The Division of Building Research wishes to thank Mr. D.A. Sinclair for the translation of this U.S.S.R. Code governing design for ice forces, and R.M.W. Frederking of this Division for checking the translation for technical accuracy.

Ottawa

January 1980

C.B. Crawford Director

SNiP 11-57-75

PART II

OFFICIAL PUBLICATION

State Commission of the Council of Ministers of the U.S.S.R. on Matters of Construction (Gosstroi U.S.S.R.)

BUILDING STANDARDS AND REGULATIONS

DESIGN STANDARDS

CHAPTER 57 Loads induced on hydraulic structures by waves, ice and vessels.

Approved

by a Resolution of the State Commission of the Council of Ministers of the U.S.S.R. on Matters of Construction,

April 30, 1975, No. 65.

SNiP Chapter II 57-75 "Loads induced on hydraulic structures by waves, ice and vessel s ", was prepared by organi zations of the Mi ni s try of Defence of the U.S.S.R. and the All-Union Research Institute of Hydraulic Engineering named for B.E. Vedeneev (VNIIG) of the Ministry of Energy of the U.S.S.R., with the collaboration of the State Planning, Design and Scientific Research Institute of Marine Transportation (Soyuzmorniiproekt) and the Black Sea Planning, Design and Scientific Research Institute of Marine Transportation (Chernomorniiproekt) of the Ministry of Maritime Fleets of the U.S.S.R., the Institute of Hydrological Problems of the Academy of Sciences of the U.S.S.R., the State Oceanographic Institute and the State Hydrological Institute of the Main Administration of the Hydrometeorological Services of the Council of Ministers of the U.S.S.R., the Moscow Construction Engineering Institute (MISI) named for V.V. Kuibyshev and the Leningrad Hydrometeorological Institute of the Ministryof Military Educational Institutions of the U.S.S.R., the Leningrad Institute of Water Transportation, the State Institute for Planning in River Transportation (Giprorechtrans) and the Leningrad Institute for Planning in River Transportation (Lengiprorechtrans) of the Ministry of the River Fleet of the R.S.F.S.R., the All-Union Planning, Surveying and Scientific Research Institute named for S.Ya. Zhuk (Gidroproekt) of the Ministry of Energy of the U.S.S.R., the State Scientific and Planning Institute of Off-Shore Oil (Gipromorneft ') of the Ministry of the Petroleum Industry of the U.S.S.R., the All-Union Scientific Research Institute of Transportation Construction (TsNIIS) and its Black Sea Division, of the Ministry of Transportation Construction and the All-Union Scientific Research Institute of Water Supply, Sewer Systems, Hydraulic Engineering Structures and Engineering Hydrogeology of Gosstroi U.S.S.R. (VNII VODGEO).

On implementation of this chapter of the 1st of January, 1976, the following are superseded:

"Technical conditions for determining wave effects on sea and river structures and shores" (SN 92-60);

Amendment No. 1 of SN 92-60, introduced by order of Gosstroi U.S.S.R., July 12, 1963, No. 185;

"Technica1 conditions for determining loads from vessels on berthing structures" (SN 144-60);

Amendment to SN 144-60 introduced by order of Gosstroi U.S.S.R., March 24, 1969, No. 33;

"Instructions for the designing of hydraulic structures exposed to wave actions" (SN 288-64) in the section on determination of loads and effects; "Instructions for the determination of ice loads on river structures" (SN 76-66)*.

-3-Editors: Eng. Troitskii E.A. (Gosstroi U.S.S.R.), Prof. and Dr. of Eng. Sciences Lappo, D.O. (All-Union Research Institute of Hydraulic Engineering, VNIIG).

S 30213-317 Instrukt.-normat, No. - III 12-75

047{0l)-76 ｾ Stroiizdat 1976

STATE COMMISSION OF THE COUNCIL OF MINISTERS OF THE U.S.S.R. ON MATTERS OF CONSTRUCTION (GOSSTROI U.S.S.R.)

Building Standards and Regulations Part II. Design Standards

Chapter 57. Loads induced on Hydraulic Structures by waves, ice and vessels

Editorial Section for Instructional-Standardization Literature Head of Section: G.A. Zhigacheva

Editor: L.G. Bal'yan Asst. editor: N.V. Loseva

Technical editors: V.M. Rodionova, N.V. Vysotina Proofreeder: E.A. Stepanova

Prepared for printing 26.2.1976 Signed over to press 24.6.76 Format 84 x 108 1/16 d.l. Typographical paper No.3 4.2 reinf. pro 1.

(4.5 ed. -ed. 1.)

Printed: 40,000 copies Ed. No. XII-621l Stat. No. 173 Price 23 kop.

Stroiizdat

103006 Moscow, Kalyaevskaya 23a

Podol Isk Press of the All-Union Printing Industry (Soyuzpoligrafprom) under the State Commission of the Council of Ministers of the U.S.S.R. on

Matters of Publishing, Printing and the Book Trade. City of Podollsk, 25 Kirova Street

State Commission of the Council of Ministers of the U.S.S.R. on Matters of Construction Building Standards and Regulations

Loads induced on hydraulic structures by waves, ice* and vessels GENERAL POSITION SNi P II 57-75 Replaces SN 76-66, SN 144-60 SN 92-60 SN 288-64 (section on determination of loads and influences)

1.1 The present standards must be followed in determining the loads and influences from waves, ice and vessels for the designing of new hydraulic engineering structures and the reconstruction of existing ones on rivers and seas.

1.2 In the present chapter of SNiP standard values are established for loads and influences on hydraulic structrues from waves, ice and vessels. The design load must be determined as the product of the normal load and an overload coefficient n which takes into account a possible deviation from the normal on the unfavourable side. n must conform to the requirements laid down in the SNiP chapter on the basic principles of hydraulic river structure design**.

1.3 Loads from waves and ice on hydraulic engineering sturctures of class I and, where the evidence demands, on those of class II as well, and also design factors of waves on open and enclosed water areas, must be defined on the basis of data from observations in nature and from laboratory i nves ti ga ti ons.

N.B. The instructions for determining the wave factors on open and enclosed water areas, as well as the terminology and basic alphabetical designations are set forth in appendices 1 and 2 to the present chapter.

* Note: Only the section on ice forces has been included in this Technical Translation.

-5-SNiP-11-57-75 CONSTRUCTION STANDARDS AND RULES PART II. DESIGN STANDARDS

CHAPTER 57

LOADS EXERTED ON HYDRAULIC STRUCTURES BY WAVES, ICE AND SHIPS

MOSCOW, 1976

6. LOADS EXERTED BY ICE ON HYDRAULIC STRUCTURES

6.1. Ice loads on hydraulic structures must be determined on the basis of reference data on ice conditions in the area in which the structure is situated for the period of maximum ice activity; the series of observations of actual conditions must cover at least 5 years.

TABLE 27

｣ｯｭｰｲ･ｳｳｩｾ･ strength, R , of ice

Sal inity of ice, S) in tons/m , for a msan Haily airtemperature, t, in C

in

l

Less than 1 (fresh water) 45 75 120 150

1 - 2 40 65 105 135

- 3 - 6 30 50 85 105

where t, °c - mean daily temperature of the air for a three-day period prior to ice action on the structure in the case of ice thickness 0.5 m or less; or, for a six-day period, in the case of ice thickness greater than 0.5 m.

S - salinity of ice, in

r

tons/m2 tons/m2 then it

The compressive strength Rc in tons/m2*, the bending strength R_f in and the crushing strength (taking local buckling into account) R_cr in should be obtained from experimental data, but if none are available is permissible:

a) to take R from Table 27;_c

b) to determine R_f from the formulae:

3

R = - R

f 4 c (114 )

for fresh water ice, and

1

R = - R

f 2 c (115 )

for sea ice;

c) to determine R_cr from the formula

R = k.R (116 )

cr J c

where k. is a coefficient obtained from Table 28. J TABLE 28 J Val ue of

ｾＮ

I

I

structure) at the action level of the ice, m;

hice - calculated thickness of ice, m, assumed equal to 0.8 of_{maximum thickness of ice over the winter period, with} 1% reliability.

Remarks:

1. The loads and effects of ice on marine structures should be determined according to the requirements of the present chapter only for calculated ice thickness of 1.5 m or less.

2. For reservoirs and lakes, and also at the high water stage of breakup on rivers south of a line through Arkhange1 Isk, Kirov, Ufa, Kustanai, Karaganda and Ust'-Kamenogorsk it is permissible to assume a crushing strength for the ice of Rcr = 45 tons/m2.

6.2 The point of application of the resultant ice load should be taken as 0.3 hi ce' in m, below the calculated water level.

The load exerted on a structure by a moving, hummocky ice field consisting of ice floes that have not frozen together, as determined according to the requirements of sections 6.3 - 6.6 of the present chapter, should be multiplied by the following coefficients: for the Baltic Sea, Sea of Japan,

Black Sea, Sea of Azov and Caspian Sea, 1.3; for the Bering Sea, Sea of Okhotsk, and the White Sea, 1.5; for the seas of the Arctic Basin, depending on the results of actual observations.

LOADS EXERTED ON STRUCTURES BY ICE FIELDS

6.3 The load exerted by a moving ice field on a structure with a vertical frontal face must be taken as the smallest value obtained from the following pairs of formulae:

- for isolated piers continous1y penetrating the ice, P1' in tons*; or, where the ice field is stopped by the supports, P₂ in ton force:

m.R bh.

J er 1ee

P2 = 0.4 v. h.

1m

lee lee £ er

- for sections of a structure (e.g. dams) impinged on by separate ice floes, P3, in tons; or, where the ice has disintegrated, P_4, tons:

P₃ = 0.7 v. h . ｾ

lee lee c

P

4 = 0.5 R b h.e 1ee

where

m_j and ITk - form coefficients taken from Table 29 for a pier with frontal face in the form of a polyhedron

(or semicircles), rectangle or triangle;

TABLE

( 117)

(118 )

(119)

(120)

Form coefficients m. and m for a pier with frontal face of form

J £

Coeffi- Poly- Rectan- Triangle with open angle in the horizontal cients hedron gle plan (degree)

(semi - 45 60 75 90 120 150 - circle) m. 0.90 1.00 0.54 0.59 0.64 0.69 0.77 1.00 J m 2.4 2.7 0.2 0.5 0.8 1.0 1.3 2.7 E: !

-9-Vice - velocity of the ice field, in m/sec, obtained from actual observations; if none are available vice can be assumed equal to the velocity of the current in the case of rivers, or, in the case of reservoirs and seas, 3% of the wind speed in the period of motion of the ice, with 1% reliability, but not to exceed 1 m/sec;

ｾ - area of ice field in m2 obtained from actual obser-vations at or near the location of the structures;

Rcr' Rc' band hi ce

have the same definitions as in section 6.1 of the present chapter.

If the ice field moves at an angle 8 ｾ 800 relative to the front of the structure (or with the axis of the pier), the ice load must be reduced by multiplying by sin 8.*

6.4 The loads exerted by an ice field against a structure with sloping profile or against an isolated pier having an inclined face in the region in which the ice is acting, should be determined as follows:

a) _{horizontal component of load Px' in tons - from} the smallest of the values obtained by formula (117) of section 6.3 of the present chapter or by the formula

b) vertical component of the load P , in tons, by z

the formula:

( 121)

(122)

*

where

kB - coefficient from Table 30; mt - coefficient from Table 31; R_f' hand b_ice

- same meanings as in section 6.1 of the present chapter.

TABLE 30

Shape of support Rectangular pier for Conical pier Structure with or structure value of b/h. s1opi ng profil e

lce

ｾＵ >5

Coefficient k_B 1 O.2b_h 1 + 0.05b 0.1 b* i ce hi ce

* Other values of k_R are dimensionless whereas this one appears to be dimensionally dependent (editor).

TABLE 31

Angle of inclination S of (ｾ

leading edge of structure

to horizontal degree 15 30 45 60 75 80 85

Coefficient m_t 0.3 0.6 1 1.7 3.7 5.6 18

N.B. On the basis of operational experience in the construction area involved, the angle of inclination of the leading edge of the structure relative to the horizontal can be increased (but not by more that 200) when ice adheres to the

structure.

6.5 The load P

S' in tons, exerted by a moving ice field against a structure consisting of a row of vertical piers place at intervals Z, _in meters, at values of b/Z _{from 0.1 to 0.9 should be based on the smallest of the}

-11-values obtained by formula (117), section 6.3 of the present chapter or by the formula

The load P6' in tons, exerted by a moving ice field against an elastically yielding pier should be based on the smallest of the values obtained by formula (117), section 6.3 of the present chapter or by the formula

P6 = 0.3 v ._{lce lce}h.

V

Rm

where

k - the coefficient of elastic yielding of the pier,_y in tons/m, determined by the methods of structural mechanics;

Rc' mj , vice' b, mE' hi ce' rt

- have the same definitions as in sections 6.1 and 6.3 of the present chapter.

(124 )

6.6 The load P_7, in tons, exerted by a halted ice field piling up against the structure under the action of current and wind should be determined by the formula

where the values of Pl' P2' P3' P4 are determined by the formulae

(126 ) P2 = 0.05 2 h._lce v_w L. lce (127 )

P3

=

lce lce

where

V

w- velocity of current beneath the ice, in m/sec, with reliability of 1%, from maximum mean values in the period of build-up, m/sec.;

W_{M- maximum wind speed during break-up, in m/sec,} with reliability of 1%;

Lice - mean length of ice field in direction of flow, in m, based on actual observations, or if none are available, Lice can be assumed equal to three times the width of the river;

iice - slope of current surface;

h._lce and ｾ - have the same definitions as in sections 6.1 and 6.3 of the present chapter.

LOADS GENERATED BY THERMAL EXPANSION OF A CONTINUOUS ICE COVER

(128)

(129)

6.7 The load q, in tons/m, exerted on continuous ice cover with a salinity of less expansion should be determined by the formula

unit length of a structure by a than 20/_ro during its thermal

-13-TABLE 32

Length of ice cover, L, m 50 70 90 120 ｾＱＵＰ

Coefficient k_L 1 0.9 0.8 0.7 0.6

where

h_t - maximum thickness of ice cover, in m, with reliability of 1%;

k_L- coefficient obtained from Table 32;

p - pressure due to elastic and plastic deformation, in tons/m2, on thermal expansion of the ice, determined by the formula

-5

P

=

\) - maximum rate of the rise in air temperature, °C/h, during the time L, in hours (over a time of 6 hours

with four periodic observations);

(131 )

II - coefficient of ductility of the ice, ton· hours/m2,

determined by the formulae:

t , ｾ -200C (132) lce II

=

ｴｾ｣･Ｉ

=

t i ce - temperature of the ice, in °C, determined by the formula

t . = t. .t n + v

2, ljJ

tee i m 0

t i ni t - air temperature, in °C, at which its rise begins; n - relative thickness of ice cover, taking the effect_o

of the snow into account, determined by the formula h

t

n =

-o h

der

hder - derived thickness of the ice cover, in meters, determined by the formula

h

=

del' t s aair h - minimum thickness of snow cover during calculation_s

period, in m, determined from actual observation data; if none available, h

=

s

(134)

(135 )

(136 )

a .

alr - coefficient of heat transfer from the air and the surface of the snow cover, in kcal/h • m2, assumed equal to 20 ｾ +

0.3

W - mean wind speed, in m/sec;

ljJ - non-dimensional coefficient read from the graph of

figure 35 for the given values of the relative ice cover thickness no' and a non-dimensional value

_ 4 • 10- 3,

F0 - h2 ' where r is in hours _{and hder}

der is in m;

Figure 35

-15-ｾ - a coefficient read from the graph of Figure 36.

1/ o V 1 ₁....1.--' 0.05 Figure 36 Curves of coefficient ｾ

"

6.S When determining the load q, in tons/m, exerted against a unit length of a structure by a continuous ice cover undergoing thermal expansion, the following requirements must be taken into account:

- for calculating the load the largest value of q determined according to the requirements of section 6.7 of the present chapter must be taken in cases where, from the available series of air temperature observations, calculation periods are adopted either with minimum air temperature and a

gradient (i .e., rate of change of temperature) corresponding thereto, or with maximum gradient and an air temperature corresponding thereto;

- for a structure inclined less than 400 from the horizontal the load g may be neglected;

- for an ice salinity S ｾ 2%, the load q must be determined by the formula

(137)

where

h_t and k_L - have the same definitions as in section 6.7 of the present chapter.

LOADS EXERTED ON STRUCTURE BY ICE JAMS

6.9 The load P

S' in tons, on a pier acted on by an ice jam should be determined by the formula

-17-where

mj and b - have the same definitions as in sections 6.1 and 6.3 of the present chapter;

h3 calculated thickness of ice jam, in m, assumed from actual observations. h₃ can be assumed on the basis of the thermal behaviour of the ice in adjacent sections of the river, but must not be more than 80% of the average depth of flow at

the discharge rate of the ice-jam period.

6.10 The load P_g exerted by an ice jam piling up perpendicularly to the front of a structure should be determined by the formula

where

B -

L._Jam length of the section of the ice jam, assumed equal to 1.5 times the width of the river in the section line of the structure, in m;

P1' P2' P3 and P4

values of the ice pressure determined by formulae (126 - 129), section 6.6 of the present chapter; the thickness of the jam should be taken in conformity with the requirements of section 6.9 of the present chapter. The current velocity and the slope of the water surface at the place of formation of the ice

jam must be determined from actual observed data, or, if none are available, by extrapolation with observed data for neighboring regions.

6.11 The load qjam! in tona/m , exerted by an ice jam piling up on a unit length of a structure placed parallel to the direction of the current (and also piling up against a bank of the river) should be determined by the formula

where

ｾ - a coefficient assumed equal to 0.7 for sandy banks; 0.8 for clayey banks; O.g for rocky banks

Pg and B - same definitions as in section 6.10 of the present chapter.

LOADS EXERTED ON A STRUCTURE BY AN ICE COVER FROZEN TO IT OWING TO A CHANGE OF WATER LEVEL

Figure 37 (a) WL ＭＭＭｾＭＭＭＭＭｾｾＭＭＭＭＭＭ (b) WL

ｾ

---y---

Diagrams for determining the loads on a structure exerted by an ice cover frozen to it owing to a change of water level (WL).

a) during rise of water level (WL) b) during fall of water level (WL). WLF - water level at freeze-up time.

-19-6.12 _{The vertical load P10' in tons, exerted on} cover frozen to it owing to a change of water level determined by the formula

a structure by an ice (Figure 37) should be

where

B - length of a section of the structure at the acting level of the ice, m;

u - rate of rise or fall of water level, m/h;

'1 - time during which deformation of the ice cover takes place owing to a fall or rise in the water level, h;

¢ - non-dimensional function of the time, determined by the formula 1 + 3 • 1OLl r 0 4... ¢

=

[

t and \l - same definitions as in section 6.7 of the present chapter.

(141 )

(142 )

6.13 The load in the form of a bending moment M, in tons • m, experienced by a structure from an ice cover frozen to it as a result of a rise or fall in the water level (Figure 37), should be determined by the formula

-.N

M

=

where the limiting value of the bending moment M_{l i m,} in exceed that determined by the formula

(143 )

where

R' and R'

p c - tensile and compressive limiting strength, respectively,

of the deforming ice cover, in tons/m 2, calculated by the formulae -400'2 R' = _RTpe II p -400, 2 R' = _RTce II c (145 ) (146 ) e R TP and RTc

- mean values of the tensile and compressive yield points of the ice, respectively, in tons/m2, obtained from the experimental data, or if not available, taken from Table 33;

'2 - time, in h, during which the water level changes by a value equal to the thickness of the ice;

kE - coefficient taken as a function of the value of -400'2 -400'2 e kE II 0.8 1 0.85 1.5 0.9 or higher 2

- same definitions as in section 6.7 of the present chapter

-21-TABLE 33

Yield points of ice Temperature of ice o t i ce C Tensile, RTp' t/m2 Compressive, 2 RTc' tIm Upper part of ice cover

from 0 to - 2 70 180

» _{- 3} » _{-10 80 250}

» -11 » _{-20 100 280}

Lower part of ice cover

» ₀ » - 2 50

_I

Definition of t i ce' °C, same as in section 6.7 of the present chapter.

6.14 The vertical load P_{l l,} in tons, exerted on an isolated pier (or mooring post) by an ice cover frozen to it, owing to a change in the water level should be determined by the formula

where

R_{f and ht - same definitions as in sections 6.1 and 6.7 of} the present chapter;

k

c - a non-dimensional coefficient taken from Table 34.

(147)

If the distance between supports ;s _{less that 20 ht, the load} exerted on the structure by an ice cover frozen to it should be determined according to the requirements of sections 6.12 and 6.13 of the present chapter.

11 TABLE 34 Va 1ue of 0.1 0.2 0.5 1 2 3 5 10 20 d , ht , Coefficient 0.16 0.18 0.22 0.26 0.31 0.36 0.43 0.63 l. k_c j where d - diameter of pier (or mooring post), m.

N.B. If the pier has a rectangular cross section with sides a and b, its diameter can be taken as d

=