Rotations and tilt
Tiltmeters to follow rotations of structural elements and bearings.
Technical guide · Structural monitoring
Static monitoring of structures
Following slowly evolving phenomena over time: deformations, displacements, rotations and cracks.
Static monitoring answers questions such as: is a crack stable or evolving? Is an element rotating? The answer is built from time series, not from a single reading.
What it observes
Static monitoring follows quantities that change slowly compared with the vibration response: deformations, displacements, rotations of elements and bearings, crack opening.
Measurements are acquired over time and organised into time series; interpretation considers trends, variations and the boundary conditions under which they were recorded.
Quantities and sensors
Crack opening
Crack meters and strain gauges to check whether a crack is stable or evolving.
Deformations
Strain gauges, including sensors embedded in reinforcement before casting.
Displacements
Changes in element position observed over time with suitable sensors.
Acquisition
Data loggers recording measurements continuously or at intervals.
Attention thresholds
Where the system provides for them, thresholds agreed with the client to flag significant changes.
How it is set up
- 01Question and phenomenon to follow
- 02Choice of quantities and measuring points
- 03Sensor installation
- 04Acquisition over time
- 05Building the time series
- 06Interpretation and reporting
Factors to consider in interpretation
- Duration of observation
- Location of measuring points
- Environmental conditions at measurement time
- Construction or service phases
- Characteristics of the sensors used
The value of static monitoring lies in the trend of the time series, read in the context of the structure, rather than in any single measurement.
Documented cases
Sensor embedded in reinforcement
Sensor installed before casting to follow the element from the construction phase.
Crack evolution
Electronic strain gauge / crack meter to check a crack's behaviour over time.
Related methods
Further topics in the monitoring cluster and the comparison with point-in-time diagnostics.
Dynamic monitoring
Vibrations and dynamic response.
Modal analysis
Natural frequencies and mode shapes.
SHM sensor networks
From single sensor to system.
Non-destructive testing
Point-in-time surveys of materials and geometry.
Frequently asked questions
- What does static monitoring measure?
- Slowly evolving quantities such as deformations, displacements, rotations and crack opening, observed over time.
- Which sensors are used?
- Depending on the question: tiltmeters for rotations, crack meters and strain gauges for cracks and deformations, with data loggers.
- Is a single reading enough to know whether a crack is active?
- No. A time series is needed to observe the trend and interpret it in the context of the structure.
- Can the system flag significant changes?
- Where the system provides for it, attention or alarm thresholds on the monitored quantities can be agreed with the client.