In structural engineering, maintenance strategies and the resulting costs depend highly on the structural type, the quality of construction execution and the systems redundancy. Nowadays, designers and constructors of large scale structures take seriously into consideration life-cycle-cost-analyses, as part of their design and maintenance strategies, aiming to optimize the overall performance and durability of a structure in terms budgetary restrictions. In an effort to reduce the maintenance and inspection costs throughout the planned lifetime of a structure, unknown risks might be induced. Smart monitoring concepts and measurements, permanently or short-termly applied, can be used as a framework for the reduction of occurring or potential risks, through the observation and recording of a structural components behaviour within predefined time periods. By the aforementioned term "`monitoring"', a process including all types of instant recording, observation and inspection is described. One of the most important advantages of a monitoring process is the possibility to set certain correcting thresholds, the exceeding of which indicates that the monitoring process is not developing as expected. Monitoring consists of (a) the quality control of the components and materials of a structure and (b) the determination of degradation processes on structures though targeted observation of alterations on mechanical, chemical or energy properties. The content of the present thesis can be summarised as following: (a) Performance of in-situ measurements on selected case studies, followed by the calibration of respective analytical numerical models, (b) model updating processes by usage of influence field concepts and field measurements, (c) small scale laboratory tests to determine the mechanical properties of the constitutive materials, (d) large scale laboratory tests on different models, (e) research regarding the efficiency and possible optimization of monitoring systems and (f) evaluation of sensor characteristics.