The Experts below are selected from a list of 7371 Experts worldwide ranked by ideXlab platform
Valeria V. Krzhizhanovskaya - One of the best experts on this subject based on the ideXlab platform.
-
anomaly detection in Earth Dam and levee passive seismic data using support vector machines and automatic feature selection
Journal of Computational Science, 2017Co-Authors: Wendy D. Fisher, Valeria V. Krzhizhanovskaya, Tracy CampAbstract:We investigate techniques for Earth Dam and levee health monitoring and automatic detection of anomalous events in passive seismic data. We have developed a novel data-driven workflow specific to our domain, which could be generalized for monitoring other systems with time series data. We use machine learning and geophysical data collected from sensors located on the surface of the levee to identify internal erosion events. In this paper, we describe our research experiments with two-class and one-class support vector machines (SVMs). We use two different data sets from experimental laboratory Earth embankments (each having approximately 80% normal and 20% anomalies) to ensure our workflow is robust enough to work with multiple data sets and different types of anomalous events (e.g., cracks and piping). We apply wavelet-denoising techniques and extract nine spectral features from decomposed segments of the time series data. The two-class SVM with 10-fold cross validation achieved over 94% overall accuracy and 96% F1-score. Experiments with the one-class SVM (no labeled data for anomalies) using the top features selected by our automatic feature selection algorithm increase our overall results from 83% accuracy and 89% F1-score to over 91% accuracy and 95% F1-score. Results show that we can successfully separate normal from anomalous data observations.
-
Crack detection in Earth Dam and levee passive seismic data using support vector machines
Procedia Computer Science, 2016Co-Authors: Wendy D. Fisher, Tracy K. Camp, Valeria V. KrzhizhanovskayaAbstract:We investigate techniques for Earth Dam and levee health monitoring and automatic detection of anomalous events in passive seismic data. We have developed a novel data-driven workflow that uses machine learning and geophysical data collected from sensors located on the surface of the levee to identify internal erosion events. In this paper, we describe our research experiments with binary and one-class Support Vector Machines (SVMs). We used experimental data from a laboratory Earth embankment (80% normal and 20% anomalies) and extracted nine spectral features from decomposed segments of the time series data. The two-class SVM with 10-fold cross validation achieved over 97% accuracy. Experiments with the one-class SVM use the top two features selected by the ReliefF algorithm and our results show that we can successfully separate normal from anomalous data observations with over 83% accuracy.
Giuseppina Prezioso - One of the best experts on this subject based on the ideXlab platform.
-
monitoring strategies of Earth Dams by ground based radar interferometry how to extract useful information for seismic risk assessment
Sensors, 2018Co-Authors: Andrea Di Pasquale, Giovanni Nico, Alfredo Pitullo, Giuseppina PreziosoAbstract:The aim of this paper is to describe how ground-based radar interferometry can provide displacement measurements of Earth Dam surfaces and of vibration frequencies of its main concrete infrastructures. In many cases, Dams were built many decades ago and, at that time, were not equipped with in situ sensors embedded in the structure when they were built. Earth Dams have scattering properties similar to landslides for which the Ground-Based Synthetic Aperture Radar (GBSAR) technique has been so far extensively applied to study ground displacements. In this work, SAR and Real Aperture Radar (RAR) configurations are used for the measurement of Earth Dam surface displacements and vibration frequencies of concrete structures, respectively. A methodology for the acquisition of SAR data and the rendering of results is described. The geometrical correction factor, needed to transform the Line-of-Sight (LoS) displacement measurements of GBSAR into an estimate of the horizontal displacement vector of the Dam surface, is derived. Furthermore, a methodology for the acquisition of RAR data and the representation of displacement temporal profiles and vibration frequency spectra of Dam concrete structures is presented. For this study a Ku-band ground-based radar, equipped with horn antennas having different radiation patterns, has been used. Four case studies, using different radar acquisition strategies specifically developed for the monitoring of Earth Dams, are examined. The results of this work show the information that a Ku-band ground-based radar can provide to structural engineers for a non-destructive seismic assessment of Earth Dams.
-
monitoring strategies of Earth Dams by ground based radar interferometry how to extract useful information for seismic risk assessment
Sensors, 2018Co-Authors: Andrea Di Pasquale, Giovanni Nico, Alfredo Pitullo, Giuseppina PreziosoAbstract:The aim of this paper is to describe how ground-based radar interferometry can provide displacement measurements of Earth Dam surfaces and of vibration frequencies of its main concrete infrastructures. In many cases, Dams were built many decades ago and, at that time, were not equipped with in situ sensors embedded in the structure when they were built. Earth Dams have scattering properties similar to landslides for which the Ground-Based Synthetic Aperture Radar (GBSAR) technique has been so far extensively applied to study ground displacements. In this work, SAR and Real Aperture Radar (RAR) configurations are used for the measurement of Earth Dam surface displacements and vibration frequencies of concrete structures, respectively. A methodology for the acquisition of SAR data and the rendering of results is described. The geometrical correction factor, needed to transform the Line-of-Sight (LoS) displacement measurements of GBSAR into an estimate of the horizontal displacement vector of the Dam surface, is derived. Furthermore, a methodology for the acquisition of RAR data and the representation of displacement temporal profiles and vibration frequency spectra of Dam concrete structures is presented. For this study a Ku-band ground-based radar, equipped with horn antennas having different radiation patterns, has been used. Four case studies, using different radar acquisition strategies specifically developed for the monitoring of Earth Dams, are examined. The results of this work show the information that a Ku-band ground-based radar can provide to structural engineers for a non-destructive seismic assessment of Earth Dams.
Maurice L. - One of the best experts on this subject based on the ideXlab platform.
-
Whalen Dam, 9-Mile Drain, Dam failures, misc. 39
Colorado State University. Libraries, 2021Co-Authors: Maurice L.Abstract:From group of images of Whalen Dam, Buckhorn Dam, 9-Mile Drain, North Poudre Canal, and Farmers Canal.39 of 99 35 mm slides.Caption: Earth Dam Failure 1951. View looking upstream at spillway
-
Whalen Dam, 9-Mile Drain, Dam failures, misc. 34
Colorado State University. Libraries, 2021Co-Authors: Maurice L.Abstract:From group of images of Whalen Dam, Buckhorn Dam, 9-Mile Drain, North Poudre Canal, and Farmers Canal.34 of 99 35 mm slides.Caption: Earth Dam Failure 1951. View through concrete spillway to rock channel downstream
-
Whalen Dam, 9-Mile Drain, Dam failures, misc. 31
Colorado State University. Libraries, 2021Co-Authors: Maurice L.Abstract:From group of images of Whalen Dam, Buckhorn Dam, 9-Mile Drain, North Poudre Canal, and Farmers Canal.31 of 99 35 mm slides.Caption: Earth Dam Failure 1951 Buckhorn Dam. View from about center of am looking at point of failure
Andrea Di Pasquale - One of the best experts on this subject based on the ideXlab platform.
-
monitoring strategies of Earth Dams by ground based radar interferometry how to extract useful information for seismic risk assessment
Sensors, 2018Co-Authors: Andrea Di Pasquale, Giovanni Nico, Alfredo Pitullo, Giuseppina PreziosoAbstract:The aim of this paper is to describe how ground-based radar interferometry can provide displacement measurements of Earth Dam surfaces and of vibration frequencies of its main concrete infrastructures. In many cases, Dams were built many decades ago and, at that time, were not equipped with in situ sensors embedded in the structure when they were built. Earth Dams have scattering properties similar to landslides for which the Ground-Based Synthetic Aperture Radar (GBSAR) technique has been so far extensively applied to study ground displacements. In this work, SAR and Real Aperture Radar (RAR) configurations are used for the measurement of Earth Dam surface displacements and vibration frequencies of concrete structures, respectively. A methodology for the acquisition of SAR data and the rendering of results is described. The geometrical correction factor, needed to transform the Line-of-Sight (LoS) displacement measurements of GBSAR into an estimate of the horizontal displacement vector of the Dam surface, is derived. Furthermore, a methodology for the acquisition of RAR data and the representation of displacement temporal profiles and vibration frequency spectra of Dam concrete structures is presented. For this study a Ku-band ground-based radar, equipped with horn antennas having different radiation patterns, has been used. Four case studies, using different radar acquisition strategies specifically developed for the monitoring of Earth Dams, are examined. The results of this work show the information that a Ku-band ground-based radar can provide to structural engineers for a non-destructive seismic assessment of Earth Dams.
-
monitoring strategies of Earth Dams by ground based radar interferometry how to extract useful information for seismic risk assessment
Sensors, 2018Co-Authors: Andrea Di Pasquale, Giovanni Nico, Alfredo Pitullo, Giuseppina PreziosoAbstract:The aim of this paper is to describe how ground-based radar interferometry can provide displacement measurements of Earth Dam surfaces and of vibration frequencies of its main concrete infrastructures. In many cases, Dams were built many decades ago and, at that time, were not equipped with in situ sensors embedded in the structure when they were built. Earth Dams have scattering properties similar to landslides for which the Ground-Based Synthetic Aperture Radar (GBSAR) technique has been so far extensively applied to study ground displacements. In this work, SAR and Real Aperture Radar (RAR) configurations are used for the measurement of Earth Dam surface displacements and vibration frequencies of concrete structures, respectively. A methodology for the acquisition of SAR data and the rendering of results is described. The geometrical correction factor, needed to transform the Line-of-Sight (LoS) displacement measurements of GBSAR into an estimate of the horizontal displacement vector of the Dam surface, is derived. Furthermore, a methodology for the acquisition of RAR data and the representation of displacement temporal profiles and vibration frequency spectra of Dam concrete structures is presented. For this study a Ku-band ground-based radar, equipped with horn antennas having different radiation patterns, has been used. Four case studies, using different radar acquisition strategies specifically developed for the monitoring of Earth Dams, are examined. The results of this work show the information that a Ku-band ground-based radar can provide to structural engineers for a non-destructive seismic assessment of Earth Dams.
Toshinori Kawabata - One of the best experts on this subject based on the ideXlab platform.
-
effect of installation geometry on dynamic stability of small Earth Dams retrofitted with a geosynthetic clay liner
Soils and Foundations, 2019Co-Authors: Yutaka Sawada, Hiroshi Nakazawa, Andy W Take, Toshinori KawabataAbstract:Abstract Geosynthetic clay liners (GCLs), used to repair small Earth Dams, are typically installed with the GCL panel placed parallel to the upstream slope of the Dam or on the surface of benches cut into the upstream side of the Earth Dam fill. While the former requires less Earthwork, leading to a more cost-effective and rapid construction, it can potentially introduce a plane of weakness if the interface shear strength between the GCL and the cover soil is less than the shear strength of the cover soil. The inclusion of benches in the upstream slope of an Earth Dam can potentially be an effective strategy for reducing the significance of this preferential failure plane, resulting in an increased seismic performance during Earthquakes. However, the expected increase in seismic performance has not yet been quantified in large-scale shaking table tests. In this study, a full-scale shaking table test on an Earth Dam with a GCL installed parallel to the upstream slope of the Dam is reported and compared to previously published results from tests on an identical Earth Dam with the GCL placed in the benched configuration under the same seismic boundary conditions. The results indicate that, for the configuration tested, the seismic deformation of the benched installation was half of that of the Earth Dam with the GCL installed parallel to the slope, providing significant motivation for adopting the benched installation method.
-
full scale investigation of gcl Damage mechanisms in small Earth Dam retrofit applications under Earthquake loading
Geotextiles and Geomembranes, 2019Co-Authors: Yutaka Sawada, Hiroshi Nakazawa, Andy W Take, Toshinori KawabataAbstract:Abstract This paper reports results of full scale testing to further explore potential GCL Damage mechanisms in Earth Dam retrofit applications in seismically active areas; in particular, to a) investigate whether shear displacements could reduce the magnitude of GCL panel overlap during Earthquake shaking; b) explore the influence of gravel particles on GCL thickness at localised point of contact; and c) observe the consequences of an accidental exposure of an uncovered GCL to short duration rainfall in terms of moisture content and effects during subsequent compaction. The results of these experiments indicate that even under severe shaking no movements were detected at the GCL panel overlap. Whereas gravel particles were observed to locally reduce the thickness of the GCL to 2.2 mm, no plowing of the particle into the GCL occurred due to a lack of shear displacement at the interface, resulting in no localised internal erosion through the barrier. Furthermore, hydration of GCL panels during construction due to surface wetting was observed to result in a state of hydration less than its post-construction state. These results indicate that although each of the three GCL Damage mechanisms cannot be ruled out to ever be relevant in practice, the performance of the GCL retrofitted Earth Dam tested was satisfactory under even severe Level 2 Earthquake shaking, and suggests that the retrofitting of small Earth Dams with GCLs is a promising strategy to improve their static and seismic resistance.
