Subsystem of structural health monitoring system (SMS, SHM)
Building tilt and elements displacement control
Nowadays tall structures are widely spread. However, even though such structures have a wide range of advantages, they belong to high-hazard class of structures and require constant structutral monitoring.
Ground base of high structures is exposed to considerable impact. If the ground settlement is uneven or there is a structural fault, then there will be witnessed changes of the building’s dimensional characteristics: deviation from vertical axis, displacement of structural elements, etc.
“Building tilt and elements displacement control” subsystem is used for timely detection of bearing structures tilt that can lead to the transition of the building state from operational into state of failure.
In the course of its operation the “Building tilt and elements displacement control” system compares the registered values to the threshold values of warning and alarm levels. If the threshold values are exceeded, a “Warning” signal (beige line in the diagram) or a “Danger”signal (red line in the diagram) is formed.
Signals from the sensors are transfered to data acquisition node via Ethernet interface. Then the data is transfered to the server for further storage. Each of the registered signals is compared with threshold values. In the case if the threshold level is exceeded there is formed an alarm notification for the operator.
Threshold level values (for structure tilt and elements relative displacement) are calculated in accordance with the applicable normative and technical documentation for the particular structure type.
Nowadays there are a lot of two-axial measuring modules for tilt control. Let us compare the most popular of the tilt meters with ZET 7X54 digital inclinometers.
All these instruments are used for tilt angle and objects displacements measurements in two axes (they are included into National Register of measuring instruments, have digital output and high precision).
However, ZET 7X54 digital tilt meters have a number of advantages if compared to similar products available at the market:
- metrological self-check function– it is possible to check and evaluate metrological specification in the course of measurements performance without de-installation of the sensor;
- LED indication – enables on-site visual perfomance diagnostics and operability check;
- “Set to zero” function allows to calibrate tilt meters for each of the axes, thus preventing critical tilt of the platform from the set coordinates.
Infrormation on dimensional and geometry characteristics shows the final result of structure deformation. The data obtained does not reveal the deformation dynamics and changes occuring in the ground base. Hence, it is reasonable to use this system as an addition to Structural health monitoring system (SMS, SHM).