V' : average flow velocity within influenced ice field range (when the flow velocity in the construction site is V, V'=V+0.0002R)
R: length of influenced ice field range (m)
(2) Load strength applied by wind τ at(tf/m)
where
wa: unit weight of air (0.0013t/m3)
Ca resistance coefficient of wind (at time of design Ca=0.004)
g: gravitational acceleration (9.8 m/sec 2)
U :wind velocity (m/sec)
R: length of influenced ice field range (m)
3.2 Tension or the main wire
Tension T can be determined from the shape of the parabo-la drawn by the loaded main wires.
(1) Load conditions
Spanlength ｌ = Distance between fixed structures 110.0m - Crown width of the supersiructure B
Effective length L = Total extension upon cornpletion 140.0m - Sheltered length of the superstructure 2C
(2) Tension calculation
(3) Design conditions
Design conditions for load calculation by section are shown Table 1.
(4) Calculation results
In design, when the main wire is 140m long and the crown width of the superstructure is 7.5m, the angle θ at the edge is 45° 44'. In this case, load strength W and tension T in section B become 2.232tf/m and 159.7ff, respectively, as shown in Tables 2 and 3. As the length of the main wire upon installation was 145m, actual angle 0 became 50 10', ☆Table 1 Design conditions
and thus x component of tension, H, decreased, making ten- sion upon installation 149.otf as shown in the parentheses in Table 3.
Table 2 Load strength acting on unit length (tf/m)
Table 3 Tension of the main wire(tf)
4. Field Observations and Research
4-1 Field observation items and general situation of ice floes
Table 4 shows field observation and research items studied from February through March 1996. Table 5 shows the state of ice floes along the shore of the Sea of Okhotsk and
Table 4 Field observation items
Table 5 General situations regarding ice floes and freezing
