Structural Monitoring and Subsidence Monitoring
Remote Datum Ltd supplies and installs remote structural monitoring equipment including subsidence monitoring equipment for:
- structural movement
- condition monitoring.
Structural Monitoring & Subsidence
Subsidence is a specific term that relates to the motion of the ground or the earth’s surface as it moves down. However, the term is colloquially used to describe the movements of a building/structure relative to the surrounding ground and the damage that may be caused by such movements.
In general parlance the term subsidence is used when the damage is by the upward or downward movement of the surrounding ground. In the UK it is highly unusual for subsidence to cause the total destruction of a building/structure except where there is extreme coastal erosion.
However, that does not mean that subsidence damage cannot be considerable and can deny the owner/occupier the use of a building where subsidence has occurred.
There is a substantial list of culprits that can cause structural property damage, including:-
- Inadequate design of foundations
- Poor construction of foundations
- Adjacent basement construction
- Ground heave (shrinkage or swelling)
- Old/New mine workings
- Changes in water table
- Vegetation adjacent to foundations
- Leaks in sewers or water supply pipes
- Adjacent construction works
- Major flooding
Subsidence is very much time related. A building that has settled some 25mm over a 100 year period is not normally in any danger; however a structure that suffers the same movement over a six month or one year period is a potential danger. Furthermore, differential settlement can have a more detrimental effect on a structure as beams/walls/floors and lintels can part company with their supports.
Monitoring deformation, settlement and subsidence on larger structures such as dams, bridges etc. has always been relatively cost effective due to the high cost of repairs to these structures. Monitoring of domestic and low rise buildings until recently was, relative to the repair, expensive.
Remote Datum Ltd has a range of cost effective remote structural monitoring solutions to enable engineers, consultants and insurers to monitor real time structural information using GPRS mobile telemetry to transmit the data back to our web bureau where it can be viewed graphically or downloaded as a spreadsheet file.
Structural monitoring equipment is particularly useful for monitoring basement construction where the party wall agreement requires that certain precautions are met to ensure the integrity of the target and adjacent buildings. The real time data alarms via SMS text and email to alert stakeholders of problems can be invaluable.
SMS text and email alarms can be configured at any time from the secure web bureau.
If you wish further information or wish to discuss your particular project, please do not hesitate to contact us.
Remote Crack Sensors & Structural Monitoring
Discrete, low cost, electronic crack sensors placed at locations where cracking is visible, or in certain cases invisible, in structural connections along with walls and floors can detect movements as small as 0.1mm. Easily installed and removed these instruments are ideal for providing engineers with real time data without the requirement to complete lots of journeys to site.
Frequently installed with a temperature sensor, it can determine whether the structural movement is occurring in relation to a temperature movement. Installed in conjunction with our other sensors, a full picture can be built up of a structure’s movement. This equipment may be hard wired together on larger structures or on an estate be part of a wireless network back to a wireless hub for onward transmission to the web portal.
Remote Tilt Monitoring
Tilt sensors; small sensors attached to the walls/floors of a building externally and/or internally will remotely monitor and record the tilt (rotation) of the walls, beams, deck of a structure. Accurate to as little as 0.01 degree they will detect minute movements of structural members giving engineers real time data along with easily web configured SMS text and email alarms, enabling an early warning of any movement out of the ordinary.
Correctly installed and located within a structure, these devices will give details of which walls/floors are rotating and if these structural segments are moving in tandem or are rotating independently of each other.
This system can be used in conjunction with our other sensors
Deformation monitoring, sometimes referred to as spatial monitoring, is used to determine if a structure, large or small, is deforming under load or due to age or inadequacy of its original design. The monitoring may be by a variety of methods. On large structures such as bridges and buildings a robotic total station is frequently used. This is an instrument that can automatically rotate and measure in three dimensions to a fixed point many metres away. In the historic areas of Amsterdam these robotic total stations are located on street corners taking measurements 24/7 to tiny mirrors all down the street. These instruments are measuring tiny bulges and height changes in the walls of the old buildings enabling an early warning should these measurements significantly change.
In the main a variety of different systems are incorporated into deformation monitoring such as crack sensors, strain gauges, tilt sensors and total stations all reporting to a central server with pre-specified parameters that trigger an alarm should the data measurements exceed the specified tolerances.
Bridges and tunnels often use deformation monitoring to ensure the integrity of the structure – in the case of tunnels to ensure the tunnel is remaining circular and not being deformed by excessive ground pressure. A bridge monitor may be checking that the bridge deck is not deforming under load.
Structural Monitoring & Condition Monitoring
With structural monitoring it is possible to monitor all aspects of a building or structure’s condition to enable analysis of possible future and early warnings of a failure, condition monitoring is particularly used in motors and machinery where vibration and sound are used to monitor the general smooth running of plant. Vibration and noise signatures are obtained by using strategically placed sensors on the target machinery. When the machine is running, any deviation from the initial signature will cause an alarm and enable preventative maintenance.
Humidity and temperature are good indicators of the health of a building. A building that has a high average humidity can be be an unhealthy workplace and may in extreme examples cause structural problems over time due to condensation on structural members and dampness on plaster causing mould. Similarly, a noisy building or noise from external sources is not a pleasant work environment and may lead to unnecessary sick leave.
Typical subsidence monitoring of a building may include:-
- Strain on structural members
- Crack sensors
- Tilt sensors
- Vibration monitoring
- Flood detection
All aspects of structural monitoring and condition measurements can be remotely monitored including subsidence monitoring, complete with early warning systems for preventative maintenance.Contact Us
Learn more about structural monitoring and subsidence monitoring here.