Combined adjustment of angle and distance measurements in a dam monitoring network

Casaca, J. M.; Braz, N.; Conde, Vasco

doi:10.1179/1752270614y.0000000106

Cited by 10 publications

(6 citation statements)

References 3 publications

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“…The implementation of new sensors may need the integration of multiple observations requiring a reformulation of the functional model of geodetic/GNSS network adjustment [ 65 ].…”

Section: Geodetic and Gnss Sensors For Precise Measurement At Specmentioning

confidence: 99%

Geodetic and Remote-Sensing Sensors for Dam Deformation Monitoring

Scaioni

Marsella

Crosetto

et al. 2018

Sensors

126

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In recent years, the measurement of dam displacements has benefited from a great improvement of existing technology, which has allowed a higher degree of automation. This has led to data collection with an improved temporal and spatial resolution. Robotic total stations and GNSS (Global Navigation Satellite System) techniques, often in an integrated manner, may provide efficient solutions for measuring 3D displacements on precise locations on the outer surfaces of dams. On the other hand, remote-sensing techniques, such as terrestrial laser scanning, ground-based SAR (synthetic aperture radar) and satellite differential interferometric SAR offer the chance to extend the observed region to a large portion of a structure and its surrounding areas, integrating the information that is usually provided in a limited number of in-situ control points. The design and implementation of integrated monitoring systems have been revealed as a strategic solution to analyze different situations in a spatial and temporal context. Research devoted to the optimization of data processing tools has evolved with the aim of improving the accuracy and reliability of the measured deformations. The analysis of the observed data for the interpretation and prediction of dam deformations under external loads has been largely investigated on the basis of purely statistical or deterministic methods. The latter may integrate observation from geodetic, remote-sensing and geotechnical/structural sensors with mechanical models of the dam structure. In this paper, a review of the available technologies for dam deformation monitoring is provided, including those sensors that are already applied in routinary operations and some experimental solutions. The aim was to support people who are working in this field to have a complete view of existing solutions, as well as to understand future directions and trends.

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“…The implementation of new sensors may need the integration of multiple observations requiring a reformulation of the functional model of geodetic/GNSS network adjustment [ 65 ].…”

Section: Geodetic and Gnss Sensors For Precise Measurement At Specmentioning

confidence: 99%

Geodetic and Remote-Sensing Sensors for Dam Deformation Monitoring

Scaioni

Marsella

Crosetto

et al. 2018

Sensors

126

View full text Add to dashboard Cite

show abstract

“…The main drawbacks of such monitoring systems were essentially the necessity of favorable atmospheric conditions, specialized personnel and expert surveyors, as well as the long duration of both the measurements and processing procedures [12]. Starting from the 1960s, total electronic motorized stations, digital levels and, in general, the introduction of automatic data reading, acquisition, recording, and telemetric transmission allowed for continuous monitoring, thus providing denser long-term data series and subsequently enhancing the capability of analyzing deformation patterns [13,14].…”

Section: Introductionmentioning

confidence: 99%

GNSS-Based Dam Monitoring: The Application of a Statistical Approach for Time Series Analysis to a Case Study

et al. 2022

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Dams are one of the most important engineering works of the current human society, and it is crucial to monitor and obtain analytical data to log their conditions, predict their behavior and, eventually, receive early warnings for planning interventions and maintenance activities. In this context, GNSS-based point displacement monitoring is nowadays a consolidated technique that is able to provide daily millimeter level accuracy, even with less sophisticated and less expensive single-frequency equipment. If properly designed, daily records of such monitoring systems produce time series that, when long enough, allow for an accurate reconstruction of the geometrical deformation of the structure, thus guiding semi-automatic early warning systems. This paper focuses on the procedure for the GNSS time series processing with a statistical approach. In particular, real-world times series collected from a dam monitoring test case are processed as an example of data filtering. A remove–restore technique based on a collocation approach is applied here. Basically, it consists of an initial deterministic modeling by polynomials and periodical components through least squares adjustment and Fourier transform, respectively, followed by a stochastic modeling based on empirical covariance estimation and a collocation approach. Filtered time series are interpreted by autoregressive models based on environmental factors such as air or water temperature and reservoir water level. Spatial analysis is finally performed by computing correlations between displacements of the monitored points, as well as by visualizing the overall structure deformation in time. Results positively validate the proposed data processing workflow, providing useful hints for the implementation of automatic early warning systems in the framework of structural monitoring based on continuous displacement measurements.

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“…In general, dams are systematically surveyed on the basis of geodetic, geotechnical and seismic methods, for example [9][10][11][12][13]. Some authors use GNSS techniques [14,15], interferometric synthetic aperture radar (InSAR) methods [16][17][18][19], spirit leveling [20,21] and motorized control total stations systems [9,22]. In [23] noted that to make intelligent decisions on the selection of the optimal combination of the sensors, their optimal location and density, the design must be based not only on the geometrical strength and sensitivity of the monitoring network, but also on a good understanding of the physical process which leads to deformation.…”

Section: Introductionmentioning

confidence: 99%

The earth-fill dam state express investigation using mechanical vibrations produced by HPP

Antonovskaya

Kapustyan

2022

Frattura Ed Integrità Strutturale

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The usage of mechanical vibrations produced by the hydropower plant (HPP) turbine may be used for seismic sounding of large-scale constructions as the earth-fill dam and its abutment contacts. Such vibrations are monochromatic oscillations on main frequencies and their harmonics produced by turbine. Seismic sensors installed on the dam's crest and inside it, if it possible, and in the area of abutment contacts register microseisms include HPP turbine operation vibrations which may be extracted by seismic data processing, i.e., filtering. We discuss two data processing possibilities: symphonious filter as the hardware one and power spectrum calculation as digital one. We consider the two case of earth-fill dams state investigations. There are the Chiryurt HPP dam (Republic of Dagestan, Russia, 9.5 m high) and the Nurek HPP dam (Tajikistan, 300 m high). We show the possibilities of seismic express investigations using signals of main frequencies produced by HPP turbine for dam sounding. For Chiryurt dam the extra fluid filtering in the central part of the dam was revealed. Nurek dam abutment contact monitoring showed the temporal variation of its stress-strain state associated with deformation variation 10-5-10-6 presumably due to regional seismicity.

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Combined adjustment of angle and distance measurements in a dam monitoring network

Cited by 10 publications

References 3 publications

Geodetic and Remote-Sensing Sensors for Dam Deformation Monitoring

Geodetic and Remote-Sensing Sensors for Dam Deformation Monitoring

GNSS-Based Dam Monitoring: The Application of a Statistical Approach for Time Series Analysis to a Case Study

The earth-fill dam state express investigation using mechanical vibrations produced by HPP

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