a)

b)

c)

Upstream

Transition

Thickness Reach

Downstream

Transition

Intact

Sheet Ice

d)

The first analysis was done by the Canadian R.J. Kennedy (1958), who was inter-

ested in the forces exerted on a boom by a pulpwood jam. To determine those forces,

he developed the following relation

+ τiB - 2*k*0λ*F *= 0

(1)

where

width of the holding area

τi =

shear stress on the underside due to water flow

coefficient of lateral thrust

λ =

coefficient of friction of the pulpwood against the shore boundary

force per unit width acting in the downstream direction (*x*-direction).

If there exists a force *f*1 exerted by the water impinging on the upstream end of the

accumulation, then eq 1 can be integrated to obtain the force at any location *x *(mea-

sured from the upstream end of the accumulation), i.e.

-2λ*k*0x

+ *f*1 -

exp * B * .

(2)

2λ*k*0

2λ*k*0

12