Geophysical monitoring

K-UTEC AG offers customised solutions within the fields of seismic monitoring, conservation of mining damage evidence, and the assessment of vibrations according to DIN 4150.

Performance and technology

  • Configuration and construction of monitoring systems
  • Seismic observatory based monitoring systems
  • Seismologic monitoring
  • Evaluation of blasting and traffic vibrations
  • Mobile vibration measurement point
  • Analogue and digital oscillation measurement technique with computer-aided signal analyses

Seismic monitoring serves the surveillance of natural and induced seismic events in the area of mining facilities. Observation systems developed by K-UTEC are able to detect changes physical and geomechanic properties within the rock mass in good time. Consequently it is possible to take appropriate action in time. Through this it becomes possible to minimise or prevent potential damage.
K-UTEC holds the official German authorities license to measure vibrations according to §26 BImSchG. Within this regulation we assess emissions and immissions of vibrations in order to conserve evidence. We calculate predictions and give advice on how to reduce those vibrations.
 
Typical applications are:
• Mining plants and quarries
• Oil and gas production
• Vibration-sensitive installations and machinery
• Gas storages
• Dams
• Building sites
• Road and railway traffic

Appropriate observatories can be installed temporarily (e.g. as mobile vibration measuring points) as well as permanently. The monitoring systems record both vibrations of external origin (for instance earthquakes, construction works or traffic) and internal sources like bearing shell damage of engines, critical oscillations of construction components or lines. Furthermore it is possible to integrate and observe additional sensors into the K-UTEC monitoring systems. Besides pressure, temperature, gas concentration or gauge levels many more properties are feasible. Permanently installed K-UTEC observatories can trigger various processes automatically in case measurements reach pre-defined thresholds: such as alarm notices by email or SMS message, power cut-off, pausing of measurements and so on.
There are a multitude of possible applications - just ask us!


Seismic shakes are registered by surface and underground seismometers. With the help of this data the magnitude and other focus parameters can be determined.

Seismic monitoring with permanent networks

A seismological monitoring system consists of many seismometer stations. These are distributed over the area to be controlled with a central registration and evaluation unit.
The positioning of the seismometers is decided upon the demands of the monitoring task, the geological situation, the accessibility and the possibilities of transmitting a signal. To reliably localise the source of an seismic event the area to be monitored should be surrounded by seismometers leaving no gaps. To be able to allocate an event to a certain area it must registered by at least four seismometers. As low energy events sometimes are not registered in the entire  area monitored the concentration of seismometers has to be configured to be sufficient. Typical positions of seismometers underground are drifts, bore holes as well as cellars and foundations of surface buildings. For the localisation of the focus usually vertical oriented one component seismometers are sufficient. They should show a high sensitivity and they should be coupled well to the ground. For additional determination of the magnitude and the focus parameters (size of the focus area, shift, tension drop, seismic momentum, etc.) the installation of at least four 3D geophones in the area to be monitored is necessary.


Schematic illustration of a monitoring system and its components: the seismic signals are registered by numerous seismometers and transmitted to the central registration unit through pulse frequency method. There the signals are demoduled and automatically evaluated. The identified events are then saved on a PC and are available for further examination.
Seismic event induced by mining registered by a K-UTEC monitoring facility, which is permanently in place

Signal transmission and data registration

For the signal transmission of individual seismometers to the central registration unit several possibilities are available (e.g. signal cable, telephone cable, radio transmission, analogue or digital). Especially for the application in mines and when the length of cables becomes too long, the transmission of monitoring data via pulse-frequency modulation (PFM) has advantages. Some of the modulators of this type developed by K-UTEC are also accredited for the use in gassy mines (according to EU design verification certificate by IBExU institute for safety engineering, certificate I M2 EEx ia  I).

The data of all seismometers join at the registration unit, is demodulated, processed for further interpretation and saved.
With a transient recorder multiple incoming channels are simultaneously and continuously scanned. The system used by K-UTEC allows - besides of the online access for controlling the system, data download and analysis - the definition of a considerable amount of trigger functions. The system is able to set off alarms via SMS or email when a certain pre set signal threshold is exceeded, for example. To limit the amount of data received seismic events are extracted and saved from the continuous data stream automatically.
Due to the modular set up of this monitoring system, the possibility to combine multiple transient recorders, which means an increase of the amount of input channels is also possible, and the various possibilities of configuring the control software there is also the potential to monitor and record other data (e.g. of gas detectors, fluid levels, closure meters, temperature control) in addition to the seismic registrations. The storage of the event data can be carried out on a PC (registration computer), which is connected to the transient recorder via network (ethernet), as well as on a hard drive directly connected to the transient recorder. This enables the measuring system to operate temporarily autonomous without a PC. For identification and chronological sequencing of the registered events a time basis as exact as possible is necessary, which can be realised by synchronisation of the timer in the transient recorder through a DCF-77 or a GPS module.


Examination and interpretation

The control and illustration of the registered events can take place directly at the registration computer. To insure a uninterrupted measuring process it is advantageous though to carry out further examinations like localisation of the focus, calculation of the magnitude, etc. on a different computer.
If monitoring systems are used in mines they also register surface and underground blasts and events further away like stronger earthquakes and rock blasts beside the seismic events in the monitoring area. Further examination must therefore insure the right identification of the event type to prevent wrong interpretation during assessment of seismicity in the range of monitoring.
For localisation of seismic events a locating programme developed by K-UTEC is available. Most important for the determination of the focus coordinates is the accurate knowledge of the propagation velocities of the seismic waves. These are derived from geological models or separate measurements.
Seismic events, either tectonical or induced by mining, only occur sporadically. Therefore a significant interpretation can only take place over a longer period of time. K-UTEC with many years of experience in this field can offer you comprehensive assistance with the planning and setting up of a seismic monitoring system as well as with the interpretation of events and the interpretation of seismicity.


IMC Cronos type transient recorder for the recording of up to 64 channels

Central registration unit and data transfer

Central registration unit

The central registration unit basically consists of:
•  demodulation unit
•  transient recorder
•  PC for data storage and processing

Transient recorder - technical specifications:
• 64 analogue input channels
• synchronous scanning of all input channels (two time bases: internal + external DCF-77 / GPS)
• 400 kHz max. scanning rate, 2 MB storage
• 16 bit resolution; input voltage: ± 100 mV, ± 500 mV, ± 2 V, ± 10 V
• integrated signal processor
• PC connection via ethernet RJ-45 (NetBios)
• standard PCMCIA connection
• internal IDE hard disc
• maximum temperature range: -40°C to +85°C
• PPP access with analogue/ISDN/GSM modem
• integrated USV

Data transfer - technical specifications:

• power supply: 12 V, 24 V, 42 V or 230 V
• nearly all types of seismometer can be connected
• up to 72 dB dynamics

optional:

• explosion protection according to EN 50014 and EN 50020, EEx-ia-I (only 12 V)


Example of a seismometer (LE 3D-DIN) for the monitoring of vibration according to DIN 4150
8 channel K-UTEC vibration measurement unit for the mobile and permanent operation

Individual measurement units

These measurement units serve as mobile or permanent monitoring devices and for the evaluation of vibration. By connecting more of these units it is possible to effectively monitor bigger areas for example to conserve evidence of possible mining damage.


Sensor system

Acceleration sensor
Various types of seismometers
3D seismometer

Vibration measurement

Being an accredited institute for measurements according to BlmSchG §26 K-UTEC AG offers vibration measurement for the evaluation of shock waves as described in DIN 4150. Part of this is the assessment of shock emissions within the scope of the conservation of evidence, the generation of prognoses as well as the consultation for reducing the correspondent vibrations.
Above this we offer our customers tailored solutions for the monitoring of all kinds of vibrations like earth quakes, shock waves due to building work, traffic or machines. With the help of the measuring systems developed by K-UTEC damaging vibrations can be recorded at an early stage. Specific measures can therefore be taken early enough to prevent or limit damage.

Suitable monitoring facilities can be installed temporarily (e.g.: as a mobile vibration measurement device) as well as permanently.

Besides vibrations from external sources (for example through earth quakes, building sites or traffic) the facilities can also register vibrations from internal sources like bearing damages of machines, critical oscillations of construction elements or lines.

As an advantage additional sensors can be integrated and monitored through the K-UTEC monitoring facilities. Furthermore it is possible to integrate and observe additional sensors into the K-UTEC monitoring system.  Besides pressure, temperature, gas concentration or gauge levels many more properties are feasible. When permanently installed the facilities of K-UTEC can be used to send automatic alarm messages via email or SMS in case pre-defined thresholds are exceeded. In addition other actions can be initiated like power shut down, the pausing of measurements, etc.

There are a multitude of possible applications - just ask us!

Measurement principle
Mobile vibration measurement device in a test run

Applications

Typical fields of use are:
• Mines and quarries / monitoring of buildings
• Oil and gas production
• Vibration-sensitive installations and machinery
• Gas storages
• Dams
• Building sites
• Control of immissions during building work and in road and railway traffic
• Control of the proof of stability


Examples

Seismogram showing the monitoring of a building close to railway tracks during the passing of a train
Seismogram from two measuring points (cellar and upper floor in a residential house) registering the vibration velocity of the shaking produced by a waste compactor