The relevant changes should be quantifiable for classification as damages and their effects on the functioning of structures adverse.
The adverse effects of damages could escalate to a point where structures become classified as unusable. Slow accumulation of damage could drive structures to this stage referred as failure. The process of implementing monitoring strategies involves making structural observations, over period, using standardised measurements and analysis. The monitoring process should provide analytical information regarding the future functioning of the structure in relation to the anticipated ageing associated with time. Since ageing of structures remain inevitable, monitoring the ageing process become crucial in minimising the possibility of structures collapsing unexpectedly. Monitoring the ageing process provides engineers with information that can be utilised when performing routine maintenance on structures. This information can also be utilised when constructing new structures through identification of problems that might occur as observed in existing structures.
SHM can be carried out on two major timelines – long-term and short-term. Short-term monitoring mainly occurs when checking the progress of projects. Long-term monitoring, however, remains the main method employed in structures intended to endure long durations of service. This monitoring aims at establishing the status of structures and remains fundamental during repairs to structures. Reports provided from such monitoring assist individuals in implementing essential repair programmes on engineering projects. Long-term monitoring can also provide information that could assist in making decisions, regarding structures’ capability to withstand extreme conditions like blasts and earthquakes. The capability of engineering structure to withstand extreme conditions relies heavily on the condition of the structure.