Monitoring of a railroad line
NGI instrumentation division has developed a monitoring system to detect earth slides encroaching on a railroad line.
The monitoring technology is based on the use of geophones. NGI and the Norwegian railway have offered access to and use of the data collected, to be used as input to a case study.
The case study is involving a basic evaluation of data (identification of what elements in the data constitutes a slide event), reliability of the determination (elimination of noise not related to sliding), and the criteria to establish alarms responding to the event. Note that the case study does not involve the monitoring system itself, which is controlled by NGI.
During the summer of 2008, a French student (Guillaume Sauvin) acquired additional data to help refine the automatic processing, especially for locating rock falls along the railroad (velocity model, travel time tables, etc). These data are under analysis. This activity is part of the ICG Prevention and Mitigation project.
Figure 4. Monitoring system at Rauberget. left) Example of slide signal, right) Example of train signal.