Rice Lake Weigh Modules/Mount Assemblies - Manual (Page 29)

1-27
SYSTEM DESIGN Wind and Seismic Effects
Figure 1-31
■ Function of Structure. Does the vessel :
1. Contain material or equipment necessary for the protec-
tion of essential facilities (hospitals, fire and police sta-
tions), hazardous facilities or special occupancy struc-
tures (schools, jails and public utilities)?
2. Contain sufficient quantities of toxic or explosive sub-
stances to be dangerous to the safety of the general public
if released?
3. Support the operation of public utility facilities?
4. 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).
Seismic Forces
Figure 1-31 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 sup-
ports, and overall dimensions such as height, length of legs,
diameter, etc.
■ The seismic zone (from Figure 1-31) in which the vessel will
be installed.
■ Is the vessel freestanding, mounted on a structure, or on the
roof of a building?
ALASKA
HAWAII
1
2B
3
3
1
2B
4
2B
1
0
2B
3
3
4
1
2B
3
3
4
3
4
3
4
2B
1
1
2B
1
1
2B
0
0
0
2A
1
2A
2A
3
0
1
0
0
2A
1
1
1
2A
2A
1
3
2B