3.2.1. ISO 4356:1977

ISO 4356:1977 [123] establishes the basic principles that should be adopted when setting up national standards, regulations and recommendations for the deformation of buildings at the limit states of serviceability. Traditionally, measurement of deformation is usually considered as static measurement rather than dynamic measurement. However, recently developed signal processing techniques can be used to reconstruct the time history of displacement by integrating accelerations twice. In fact, deformation of structural components is quite important in monitoring; when the deformation approaches the threshold at limit states of serviceability, an alert should be issued by the SHM system. Although this code was drafted for the purpose of building design, it can also be used as guideline for design of monitoring system since it provides the basic principles to determine the deformations of buildings at the serviceability limit states, which can also be considered as the base for answering the critical question that how to evaluate the health condition of the building based on the monitored data.
