The lab concerned the resultant hydrostatic and hydrodynamic forces on flooded structures.

If you were tasked with building a critical infrastructure, for example a flood evacuation

structure, which of the following statements would you pick to describe best your design?

$(2$ Marks$)$

Select one:

a$.$ A flood evacuation structure is built for a single purpose, to provide a safe refuge to

persons during an event, and ideally for a short time afterwards to facilitate rescue.

A flood evacuation structure should be built to resist hydrostatic and hydrodynamics

loads. Hydrostatic loads can be reduced by constructing the structure without walls,

effectively a steel or reinforced concrete shell. This means the effective value of $b$ is

small, and hence the hydrostatic load is small. This also reduces hydrodynamic drag,

especially if the structure members are streamlines in shape, and allows debris to

pass through the structure, reducing impact forces. The structure should be higher

than the expected flood levels, and the refuge floor will be covered to provide

shelter and facilities such as emergency communications, rations and first aid should

be provided. The roof should be helicopter capable.

b$.$ The most important aspect of force is the hydrostatic force. Therefore a flood

evacuation structure should made from extremely thick reinforced concrete walls

with no openings except for a heavy door that can be sealed shut. This will mean the

hydrostatic force is negligible. This way, the structure does not need to be higher

than the expected flood levels, saving costs, and can be made larger to contain more

people for less money.

c$.$ The most important aspect of flood force is the hydrodynamic drag force. Therefore

a flood evacuation structure should be streamlined to the expected flood direction.

For example, an oval shape. This will reduce the hydrodynamic drag force. Strong

concrete walls will mean that the hydrostatic force is not significant. The structure

should be higher than the expected flood levels, and the refuge floor will be covered

to provide shelter and facilities such as emergency communications, rations and first

aid should be provided. The roof should be helicopter capable.

d$.$ Flood evacuation towers should not be provided as this encourages people not to

evacuate an area in case of flooding.