CressHelp - Ice forces

Cress Help - Ice forces - A21.6

Forces by thermal expansion

Forces caused by the thermal expansion of ice (see [g]):

Under the influence of sunlight for example the ice expands. If an ice cover is prevented from expanding (e.g. ice between two bridge piers) the ice will exert a maximal horizontal linear load of:

equation 1

in which:

Fmax = maximum force per running metre of ice cover (linear loading) [kN/'m]
h = ice thickness [m] hs: thickness of snow layer lying on the ice [m]
Tl = average air temperature of the previous 24 hours [°C, absolute values]
DTl = the maximum rise in air temperature within a given period Ät within the previous 24 hours [°C]

Dt = period during which the temperature is rising [hours]

y = coefficient [-]

y = 1 for an ice-cover length (L) up to 50 m
y = 0.9 for 50 < L < 75 m
y = 0.8 for 75 < L < 100 m
y = 0.7 for 100 < L < 150 m
y = 0.6 for L > 150 m

Later it is necessary to check that the force does not exceed the failure compressive strength of the ice.

References
[a] ing. C.J.A. Zijlmans, IJsbezetting -bestrijding op de grote rivieren in Nederland, Literatuurstudie, Rijkswaterstaat, Dir. benedenrivieren, afd. AXB, org. IJsopruiming, sektie onderzoek, nov. 1980.
[b] Stormvloedkering Nieuwe Waterweg, document ontwerp, deel 1, RWS Directie sluizen en stuwen, 31 juli 1989, BMK.
[c] ir A.W. de Haas, april 1986, Ice afvoerproblematiek voor de grote rivieren en de Rijndelta, bijzondere onderwerpen, RWS dir. Benedenrivieren, Organisatie IJsopruiming Sectie Onderzoek.
[d] ir T. Stoutjesdijk e.a. Grondmechanica Delft, oktober 1991, Taludbekledingen van gezette steen, bijzondere belastingen, co-320030/3.
[e] H.R. Kivisild, Proceedings 8th IAHR-congres 1959, Montreal-Canada-Volume III, "Ice problems in hydraulic structures.
[f] ir F. Gerritsen, Proceedings POAC-conference "The first international conference on port and ocean engineering under Arctic conditions", Vol. I Norway 1971, Ice problems in Dutch rivers and estuaries, blz. 582 e.v.
[g] Korzhavin, K. N., Action of ice on engineering structures, Novosibirsk, Akad. Nauk. USSR 1962.Vertaling: TL 260 van CRREL Hanover, New Hampshire, 1971
[h] Russische ontwerpregels uit 1986.
[i] Carstens T. editor, Working group on ice forces on structures, A State-of-the-art report, special report 80-26, june 1980.