Displacement and deformation monitoring is among the special-purpose works with the highest demands on accuracy and on dedicated technology. We use precise levelling for vertical displacements, precise total stations and permanently marked points with fixed targets for spatial displacements; where an area-wide picture of the deformation is needed, we deploy laser scanning.
The key is a carefully built reference network: points outside the reach of the deformation zone whose stability is verified continuously. The results are evaluated against the baseline epoch, including an accuracy analysis – we distinguish a real displacement from measurement uncertainty, so the structural engineer receives values that can be relied on. We work in accordance with the Czech standard ČSN 73 0405 (Measurement of displacements of building structures).
A one-off check and long-term geodetic monitoring rest on the same foundation. For long-term monitoring we design the layout of points, the frequency of epochs and the critical values together with the designer or the structural engineer; if those values are exceeded, we report it immediately. We observe not only the structure itself but also the surrounding development affected by the construction works – a survey of the initial condition and repeated measurements protect the client in any dispute.
Typical tasks: settlement of new buildings and halls, the behaviour of buildings during construction next door, tilts of tall structures, deflections of roof trusses and crane runways, or stability checks of retaining walls and slopes.
