The objectives of structural design may be summarised as follows
1- Safety
The structure should be able to carry all expected loads safely, without failure, that is, without breaking or collapsing under the loads.
3- Stability
To prevent overturning, sliding or buckling of the structure, or parts of it, under the action of loads.
4- Strength
To resist safely the stresses induced by the loads in the various structural members.
5- Serviceability
To ensure satisfactory performance under service load conditions – which implies providing adequate stiffness and reinforcements to contain deflections, crack-widths and vibrations within acceptable limits, and also providing impermeability and durability (including corrosion-resistance), etc. There are two other considerations that a sensible designer ought to bear in mind, viz., economy and aesthetics. One can always design a massive structure, which has more-than-adequate stability, strength and serviceability, but the ensuing cost of the structure may be exorbitant, and the end product, far from aesthetic.
