Page 48 - Vol.06

Tech
Notes
技術專文

Solution: 3000 mm

150 mm

W530 x 66

Figure 6

W530 x 74

80 mm
If this footbridge located indoors, it would not 50 mm
be satisfactory because the limit is 0.015 W460 x 52
10.5 M W460 x 52 DO DO DO
Example 2 SECTION

Determine if the hot-rolled framing system for
the typical interior bay satisfies the criterion for
walking vibration. The structural system supports
office floors without full height partitions. Use 3 SPA @ 3m
0.5 kPa for live load and 0.2 kPa for the weight of PLAN
mechanical equipment and ceiling. Figure 7
Solution:

• Design For Rhythmic Excitation
The peak acceleration of the floor due to a harmonic
rhythmic force is obtained from the classical solution by
assuming that the floor structure has only one mode of
vibration (Allen 1990):

with , the equation (2) becomes

And when it becomes

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