The basic function of a building is to provide structurally sound and environmentally controlled spaces, protect occupants and contents. If this basic function is not achieved, it is because some aspect of the building has failed. The source of deficiencies can include inadequate design, improper execution of the work, defective materials, or simply normal and expected ageing perhaps coupled with lack of maintenance
Structural failures can occur from a range of different sources. The type of failure is associated with the nature, environment and application of the structure. Some of the reasons are
Weak Structures: The structure is not strong enough to withstand the load which is subjected to it. This is usually due to inappropriate geometric design or material choice.
Structural Deterioration: The structure deteriorates due to corrosion, fatigue, wear or creep. Fatigue failures begin when cracks form at regions of high stress. These cracks grow when subject to cyclic loading, resulting in sudden failure.