Dam monitoring based in GNSS (GPS, Glonass, Galileo, ..)
Leader team in GNSS based monitoring systems for dams, with the very first worldwide experiences. Equipo líder en la implantación de monitoreo mediante GNSS con primeras experiencias mundiales.
INTERCONTROL as integrator, CIFRES LTD as software developer and eWATER as Engineering consultant, are partners for COMPASS-GNSS and COMPASS-DATA, most modern tools for a new generation of Smart dams. INTERCONTROL como integrador, CIFRES LTD como desarrollador de software y eWATER como consultora de ingeniería, forman un partenariado para COMPASS-GNSS y COMPASS-DATA, las herramientas más modernas para una nueva generación de Presas Inteligentes.
Nuestro software 4DTracknet incluye algoritmos propios desarrollados por Cifres Ltd que permiten una precisión y fiabilidad máximas en la tecnología actual, pudiendo generar valores estimados de desplazamientos con su incertidumbre asociada y la detección de comportamientos anómalos.
Our 4DTracknet software includes our own algorithms, developed by Cifres Ltd, providing best accuracy and reliability in the nowadays technology. It releases estimated values of displacements as well related uncertainties and anomaly detection.
Rapid response, in many cases with difficult access constraints (remote or mountainous locations) and with adverse weather conditions, reason why there is an effort for the automation of the monitoring systems that should never lead to an absence of direct visual inspection. In most of the cases, the first hints of malfunctioning come from the hydraulic component, with rising interstitial pressures and uplift, leaks or even suspended materials in the leaks. It is however essential to confront these parameters with their effect in the structure through its kinematics.
Therefore, the inclusion of Compass-GNSS system for the detection and tracking of movements, demand a high grade of accuracy and reliability, apart from availability in adverse conditions. The capacity to provide early warning, even with lower levels of accuracy represents a qualitative leap for the dam safety monitoring. All these features are possible thanks to the 4DTracknet software of our partner Cifres Ltd
Our references started in 2003, being the 1st team in the world succeeding in development of GNSS based systems for dam monitoring.
GNSS systems have been regarded as lacking in accuracy,
In many cases it will provide accurate enough data for a diagnosis of dam behavior, and uncertainties about trend.
New developments in Compass-GNSS system, differential processing algorithms under different predictive models enable satellite position technologies to provide accurate enough and reliable information to be implemented confidently in dam safety monitoring schemes.
Main concerns about precision can be seen as old prejudices as nowadays, data processing is able to provide information with errors about some few millimeters, as proven in Spanish dams.
Special filtering after differential processing allowed to reduce measurement noise and to provide an assessment of the involved uncertainty. Not only raw data, but confidence of them needs to be known.
Complementarity with conventional systems is still necessary while confidence from safety managers consolidates. The combined design of conventional Compass-GNSS can lead to savings by using the latter for early warning while the former, with higher operational costs, can be useful for the definitive diagnostic of anomalous behavior.
DAMS WITH DIFFICULT ACCESS
Dams located in areas with difficult access or seasonal constraints can be properly monitored in real-time triggering detailed inspections based on alerts. The operational costs of the combined use are reduced so that the savings can be used to improve safety control.
When dams are located in canyons of mountainous areas, a careful planning is required in order to ensure a good reception of the satellite signals. Likeliness of lightning events must also be considered as they can affect power and communication systems.
COMPLEMENTING OTHER DEVICES
In most cases GNSS monitoring will be a complement rather than an alternative to the conventional methods,
but delivering an added value based on two key lines:
• Operation conditions
• Data interpretation
Some instrumentation systems for precision geotechnical monitoring, like rod extensometers are not substitutable with GNSS and are easily automatable. Regardless of the high cost, they will be still needed due to their important role.
Acelerometers identify dynamic movements but no final deformation. Compass-GNSS could complement seismic surveillance by providing residual non elastic deformations.
CONFIDENCE IN BEHAVIORAL MODELS
Different predictive behavioral models allow the use of raw data to derive different behavioral hypothesis, leading to improvements in the displacement forecast while delivering additional information about statistic confidence in the proposed models. This feature of certain processing systems as Compass-GNSS enables the validation of behavioral hypothesis, being of great help for the experts in charge of the safety assessment of the dam.