Direction: Beam GHI is supported by three pontoons as shown in the figure below. The horizontal cross-sectional area of each pontoon is 8 m2, the flexural rigidity of the beam is 10000 kN–m2 and the unit weight of water is 10 kN/m3.
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When the middle pontoon is removed, the deflection at H will be
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- 0.2 m
- 0.4 m
- 0.6 m
- 0.8 m
Correct Option: B
Consider that middle position is removed.
Reaction, cluts RG = RI = 24 km (48/2)
This is supported by flotation.
∴ A.rω.rω × h = 24
8 × 10 × h = 24
h = 0.3 m
Deflection at H
| = | 48EI |
(similar to a simply supported beam)
| = | = 0.1 m | 48 × 10000 |
∴ Total deflection = 0.1 + 0.3 = 0.4 m
