Bridges Structural Health Monitoring and Deterioration Detection Synthesis of Knowledge and Technology

INE/AUTC 10.0

The Utah Pilot Bridge, Live Load and Dynamic Testing, Modeling and Monitoring for the Long-Term Bridge Performance Program

As part of the Federal Highway Administration\u27s Long-Term Bridge Performance Program, Live Load and Dynamic tests were conducted. A long-term monitoring plan was developed and presented for the Utah Pilot Bridge based on Live Load and Dynamic tests. As one of seven pilot bridges, the Utah Pilot Bridge is one of the first bridges used to initiate the LTBP Program. A formal permit approval process, with the Utah Department of Transportation, was followed to gain permission to conduct the tests and install long-term instrumentation. Analysis provided good results for each test completed, with a summary of test results presented. A Finite Element Model was created and refined based off test data. Instrumentation was installed and checked to ensure quality data was streaming to the collection site

Determining Natural Frequencies Using Embedded and Placed Sensors under Ambient and Shaker Excitation

Dynamic monitoring of structures is a method of detecting changes and damage to the structure. Vibration based monitoring has been used to detect damage in rotating machinery and is gaining popularity in the field of Structural Health Monitoring (SHM). Monitoring involves detecting changes in natural frequencies and changes in mode shapes. These changes reflect changes to properties of the bridge which can indicate damage. The Nibley Bridge is a single span bridge comprised of ten deck bulb girders. The bridge spans 25.91m (85 ft.) and includes two lanes, sidewalks on both sides, and a small median. The Nibley Bridge was constructed with monitoring in mind. A dynamic monitoring system was planned to detect frequencies for long term monitoring. Initial monitoring of the embedded accelerometers was ineffective, so additional testing was required. An impact test was done with additional sensors to calibrate the embedded sensors. To further define the natural frequencies and mode shapes of the bridge, two shaker tests were also performed. The embedded sensors were noted as having a large noise range. Also, they required a specific data logger to detect meaningful data. Recommendations for the use of the embedded accelerometers were determined and defined. The additional tests were able to assist in calibrating the accelerometers, as well as defining the natural frequencies and mode shapes of the structure. Natural frequencies were defined for each test and the changing condition of the bridge between those tests. The addition of asphalt occurred between two tests and a change of approximately 20° C between the other two tests. Though there is not much information to form a correlation, the detected changes define the dynamic aspects of the bridge. Lastly, mode shapes were determined and a Modal Assurance Criterion (MAC)analysis was done to correlate the measured and analytical mode shapes. This model helped to indicate which parameters effect the mode shapes of the structure. Comparison between these parameters and changes between them help to indicate the predicted behavior of the structure under different circumstances. Though these tests do not define all of the dynamic properties of the bridge, they do provide a general baseline of values that can be expected for future tests of the structure

DEVELOPMENT OF A FIELD-BASED MOBILE PLATFORM FOR PLANT PHENOTYPING

Design, implementation and performance verification of an affordable field-based high-throughput plant phenotyping platform for monitoring Canola plants, including both data acquisition/visualization software and measurement system, was the main objective of this research. The primary motivation for this research is the fact that breeders need a well-organized approach and efficient tool to monitor and analyze a number of plant traits to achieve a higher yield. At the moment, manual measurement is a conventional approach to gather the required information for plant analysis. Nevertheless, manual measurement has many limitations especially to study a large-scale field. To address this bottleneck, a high-throughput plant phenotyping platform (HTPP) was developed which consists of a data acquisition system, a data storage unit, and a data visualization and analysis software. Such an HTPP will be an essential asset for breeders to conveniently gather a comprehensive database which contains various information such as a plant height, temperature, Normalized Difference Vegetation Index (NDVI), etc. To develop and implement such an HTPP, first, the overall system block diagram and required algorithms were drawn. Then to find the optimum set of equipment according to the requirement of this application, the performance of different sensors and devices were examined using literature search and experimental examinations in the laboratory setting. Then a mechanical boom was attached to the rear of a farm vehicle (a Swather) to carry different sensors, cameras and other measurement equipment (mechanical development of the boom structure was carried out by other members of the research team). A control box containing power supplies, safety fuses, and a data logger unit was attached to the farm vehicle, and a program was developed for data logger to read sensors signals as well as GPS data for data geo-referencing and future retrieval purposes. The efficiency of different system architecture including different data transmission networks was examined by conducting several field tests to minimize existing errors such as delays in synchronizing different steps. Three programs were developed in MATLAB GUI for image acquisition via webcam and DSLR cameras as well as a central program for data processing and interactive data visualization. The indoor tests were performed at the Robotics laboratory, University of Saskatchewan and outdoor experiments were performed on a Canola nursery at Cargill Canada, Aberdeen, SK, throughout spring-summer 2016 and 2017. Finally, the performance and effectiveness of the developed field-based phenotyping platform was validated by various measures such as conducting some manual measurements and comparing the results with the values given by the platform. According to the achieved results, both hardware and software components of the proposed system meet the requirements of a field-based plant phenotyping platform as an essential asset for breeders for comprehensive study of Canola plants or any other cultivars as a result of some minor design modifications. The main contributions of this study to plant phenotyping research are autonomous image acquisition capability, enhancement of the data acquisition cycle to minimize data geo-referencing error, development of a modular program for data visualization in MATLAB, and faster data collection in a high-throughput fashion (almost 125 times faster)

VEHIOT: evaluation of smartphones as data acquisition systems to reduce risk situations in commercial vehicles

Proceeding of: 2018 IEEE International Conference on Vehicular Electronics and Safety (ICVES): Madrid, 12-18 Septermber 2018.Vehicle dynamics studies are an indispensable characteristic to improve the vehicle stability and handling. To fulfil this requirement, control systems are included in commercial vehicles nowadays. These control systems consider variables such as lateral acceleration, roll rate and sideslip angle, that can be directly obtained from sensors or estimated from the collected data. With the objective of incorporating control systems without increasing the price of these vehicles, it is necessary to develop low-cost embedded systems, capable of acquiring data from a diversity of sensors to execute estimations and to perform control actions under real-time constraints. The increase of capabilities and features provided by smartphones enable them as data acquisition and processing devices. In this paper, an analysis in terms of reliability, accuracy and acquisition have been performed for two different smartphones in order to study the possibility to use this kind of devices as a low-cost sensing platform for vehicle dynamic applications. Each smartphone used in this study is classified into a different category (low-end or high-end device) depending on not only its price but also its specifications. Both yaw rate and lateral acceleration have been analyzed in order to quantify the performance of each smartphone. These variables have a direct influence on the vehicle lateral dynamics. Experimental tests have been carried out in a real scenario and the VBOX IMU connected with the VBOX 3i data logger of Racelogic has been used as the ground truth.The authors gratefully acknowledge the funding by Ministerio de Economa y Competitividad, Spain, under the grant TRA2013-48030-C2-1-R

Electronic instrumentation of coal slurry impoundments for real-time data collection to support automated monitoring

Following the breakthrough and release of coal slurry from the Martin County Coal Corporation impoundment near Inez, Kentucky on October 11, 2000 the United States Congress requested the National Research Council (NRC) to examine ways to reduce these types of accidents. The NRC completed their study titled Coal Waste Impoundments which identified numerous areas of concern and the committee presented recommendations for improving the design, operation, and safety of coal slurry impoundments. This research addresses the National Research Council\u27s findings for introducing state-of-practice electronic instrumentation for monitoring parameters within the embankment and slurry pool area of an impoundment. This research will improve impoundment stability, safety, and environmental compliance monitoring. Previous research performed by West Virginia University (WVU) in 2003 at nineteen coal impoundments within West Virginia indicated no occurrences of electronic instrumentation in use for the real-time collection and emergency warning annunciation of important safety and environmental related parameters. The research identified that coal company operators and their design engineers were not familiar with the new instrumentation equipment and systems.;This research project has been initiated by the National Technology Transfer Center (NTTC) Coal Slurry Impoundment Project which funded WVU for the development of a prototype wireless data collection system for monitoring impoundment performance, safety, and environmental indicators at Eastern Associated Coal Corporation\u27s Rocklick Impoundment located in Greenwood, Boone County, West Virginia. The scientific accomplishments of this research as reported herein include the engineering design, instrument system fabrication, assembly, and field construction of a prototype automatic wireless data collection system for monitoring impoundment performance (weather data, piezometric water levels, pH, Specific Conductance, and Oxidation Reduction Potential)

Implementation of structural monitoring to assess the performance and serviceability of concrete and steel girder bridges

This research focuses on bridges and the development of structural monitoring systems used for both concrete and steel bridges. Parts of two bridges were built with a combination of sensors attached to a data acquisition system powered by a solar panel and battery, where data is transmitted wirelessly through cell phone technology. The research represents the first efforts to develop remote structural monitoring that is robust and reliable to survive through the construction of both concrete and steel bridges and continue to function from the beam fabrication through bridge construction and even now as the bridges have been in service for more than two years.Prestressed Concrete Bridge Beams were instrumented during beam fabrication. Concrete strains, concrete temperatures, and ambient temperatures are measured continuously from the time immediately before the casting of the beams, through fabrication, including detensioning of prestressing strands, through handling and storage, transportation, and erection, through bridge construction, and now during life-in-service. Sensors capture concrete strains and temperatures from early ages. These data are useful to assess important variables regarding the design and construction of prestressed concrete bridge beams and the bridges made with those beams. Specifically, prestress losses were assessed, and beam cambers were measured. Designs were varied to investigate different design choices to control and limit both prestress losses and cambers.In-situ load testing was performed on the completed concrete bridge structure. These data are used to investigate design parameters, specifically distribution factors for bridges' design and load rating and the dynamic amplification factor for bridges. Recommendations are made from the research.Findings from the research demonstrate the effectiveness of including fully tensioned top strands in prestressing strand patterns and mild horizontal steel as part of the primary reinforcement at midspans of bridge beams. The research shows that both of these design choices are effective in limiting prestress losses and beam cambers. These techniques can be employed nationwide and worldwide where precast, prestressed concrete bridge beams are used