Selected methods of measuring deformations as a part of a system for monitoring structures

Abstract

Real-time evaluation of deformations, like stress, strain, displacements of structure components can provide essential information about the state of the structure. It's very important to assess correctly the condition of the structure, to identify its most important parts to be measured. In order to achieve this goal, it is necessary to choose proper methods of measurements and right instruments. The geodetic techniques of acquiring information about deformations have recently strongly intended for remote methods. This trend can be observed for example in using reflectors for distance measurements, interferometry, scanning or remote sensing methods. Very promising are also approaches employing instruments like clearance gauge or dial gauge. Evaluation of structure deformations is quite sophisticated. It cannot be carried out by geodesists alone on every day routine. The paper presents different measurement methods of deformations for different structures ranging from buildings to bridges, together with the attempt to determine the most suitable ones for each of them. The best technique is chosen based on the accuracy requirements, length of the measurement time and the total cost of the survey including its data processing. Finally the paper takes into consideration that some of the methods need to be backed up by alternative ones and proposes the idea of combining techniques to achieve the goal.