Rice Lake Z6 Single-Ended Beam, SS Welded-seal, IP67, OIML C3 - Manual (Page 53)

Wind and Seismic Effects on Vessel Stability 49
Figure 22-5.
• Values are fastest mile speeds at 33 feet above
ground for Exposure Category C and are associated
with an annual probability of 0.02.
• Linear interpolation between wind speed contours is
acceptable.
• Caution in use of wind speed contours in
mountainous regions of Alaska is advised.
• Wind speed for Hawaii is 80 and Puerto Rico is 95.
• Wind speed for Alaska varies from 70 inland to over
110 in coastal areas.
• Where local records or terrain indicate higher
50-year wind speeds, they shall be used.
• Wind speed may be assumed to be constant
between the coastline and the nearest inland
contour.
22.3 Seismic Forces
Figure 22-6 on the next page is a seismic zone map of the
United States. The various zones are numbered 0 (little
likelihood of damage) through 4 (likelihood of major damage)
which indicate, on an ascending scale, the severity of damage
likely as the result of earthquakes. The effects of seismic
forces should be considered on vessels being installed in
zones 1 through 4.
The following information is required in order to perform a
complete seismic analysis.
Vessel: The vessel’s dead and live weights, number of
supports, and overall dimensions such as height, length of
legs, diameter, etc.
The seismic zone (from Figure 22-6) in which the vessel will be
installed.
Is the vessel freestanding, mounted on a structure, or on the
roof of a building? Function of Structure. Does the vessel :
• Contain material or equipment necessary for the
protection of essential facilities (hospitals, fire and
police stations), hazardous facilities or special
occupancy structures (schools, jails and public
utilities)?
• Contain sufficient quantities of toxic or explosive
substances to be dangerous to the safety of the
general public if released?
• Support the operation of public utility facilities?
• Perform a function not listed above.
Site geology/soil characteristics and the vessel’s structural
period, if available.
With this information, the forces resulting from seismic activity
can be calculated according to methods described in the
Uniform Building Code (UBC).
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Basic wind speed 70 mph
Special wind speed region