Deformation monitoring

Under deformation monitoring is the systematic measurement and permanent observation of changes in the shape or dimension of an object.

For this purpose, measurement data is recorded and recorded, which is used for further calculations, deformation analysis, predictive and preventive maintenance and notifications when predetermined limit values are exceeded.

Deformation monitoring primarily relates to the field of applied measurement and is mainly used for construction objects, in mechanical and plant engineering as well as in soil and rock mechanics.

The reasons for the necessary use of deformation monitoring are changes such as shifts in the subsurface, decreasing or increasing loads, changes in material properties or external influences.

The measuring instruments (1) used for deformation monitoring depend on the application (2), the selected method (3) and the required system (4).

Measuring instruments

The measuring instruments (or sensors) can be divided into two groups, the geodetic and the geotechnical sensors. Both groups can be seamlessly combined with one another in a modern monitoring system.

Geodetic measuring sensors detect possible displacements or movements in position and / or height in a georeferenced manner . Instruments such as total stations , levels and receivers for global navigation satellite systems (GNSS) are used for this purpose.
Geotechnical measuring sensors do not record displacements or movements georeferenced, but measure physical properties. These sensors include extensometers, piezometers , rain gauge , thermometer , barometer , electronic scales hose , inclinometers , accelerometers , seismographs , etc. For more information, see Geotechnical sensors .
Other measuring sensors such as B. Radar gauges .

application

Deformation monitoring can be used to record movements in the following objects:

Dams and dams
Streets
tunnel
Bridges and overpasses
Tall buildings and historic structures
Foundations
construction sites
Mining and mines
Slopes and volcanic slopes
Settlement areas
Earthquake areas

Procedure

Deformation monitoring can be carried out manually or automatically.

With manual deformation monitoring , instruments or sensors are manually, i.e. H. at irregular intervals and mostly without permanent installation (e.g. for simple preservation of evidence).
An automatic deformation monitoring consists of a group of interactive, related or independent software and hardware components, which together form a complex for deformation monitoring. As soon as the necessary components are installed and prepared for real-time data acquisition and transmission, no further human intervention is necessary.

This definition does not include deformation analysis and interpretation based on the data recorded by the monitoring system. This is the job of the deformation analysis software. An automated monitoring system is usually permanently installed, especially if objects are to be monitored permanently or in certain cycles.

Systematics and scheduling

The system and process planning depend on the object to be monitored and the application. Objects can move or change quickly, at high frequencies, slowly and gradually. For example, a bridge sways due to wind and traffic, but it can also shift gradually due to tectonic changes.

Systematics : at intervals of days, weeks or years with manual monitoring and permanent data collection with automated monitoring systems
Measurement intervals : at intervals of fractions of a second up to a few hours

Risk management

Deformation monitoring systems provide a proactive control of possible hazards that are caused by changes in natural events or structural objects. Policyholders can minimize any risks before and after a construction project and receive insurance premiums on better terms for the entire life of a property. Further information can be found under Risk Management .

credentials

^ Literature, Edited by JFA Moore (1992). Monitoring building structures . Blackie and Son Ltd. ISBN 0-216-93141-X , USA and Canada ISBN 0-442-31333-0

Web links

[1] Literature, Edited by JFA Moore (1992). Monitoring building structures . Blackie and Son Ltd. ISBN 0-216-93141-X , USA and Canada ISBN 0-442-31333-0