| PaperNO | Paper / Abstract |
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SE10-015
11:50
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12:05
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SCOUR STABILITY EVALUATION OF BRIDGE PIER CONSIDERING FLUID-SOLID INTERACTION
As the development of human civilization, transportation has become an indispensable part of daily live, which form a large demand on river crossing bridges. Due to typhoon or flooding, scour at bridge piers poses huge threat to stability, bearing capacity and other performance of bridge foundation. For traditional static evaluation, however, fluid behavior is simplified by linear force distribution when current force is considered, which may cause the overestimate of stability because of the negligence of nonlinear force generated by down flow, wake verities and other fluid behavior in the vicinity of pier. In order to consider the complicated fluid impact, finite element simulation is applied in this study by creating a fluid-solid interaction (FSI) system. In FSI system, simulation result for both fluid and solid system is transferred to each other at each time interval. In this way, the force generate by fluid system can be added back to solid system to estimate the dynamic response of pier. In this study, a scaled single pier scour test is conducted by both experimental test and finite element program. By analyzing the dynamic data collected in experimental test, the natural frequency of pier at each scour depth can be defined, which is later compared to results from numerical simulation. According to the low error of natural frequency, the established FSI system is able to conduct pier scour simulation correctly while considering fluid-solid interaction, and can be further applied in practical engineering bridge simulation, which will be applied as a guideline for bridge and traffic control that supports disaster prevention and evacuation while flood strikes bridges.
Po-Wei Chen, Tzu-Kang Lin
bridge scour, fluid-solid interaction,, soil spring, stability evaluation
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SE10-011
11:05
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11:20
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TWO-YEAR MONITORING PROJECT ON A REPAIRED EARTHQUAKE DAMAGED BRIDGE USING OPTIC FIBER DIFFERENTIAL SETTLEMENT SENSORS
This paper is about the design and the application of optic fiber differential settlement measurement sensor (DSM) for the health monitoring on a repaired earthquake-damaged bridge. To share the DSM practical field-experience is the aim of this study. At the beginning of this article, this study briefly reviews the development history of optic-fiber sensor. Secondly, a simple-structured DSM sensor is proposed and expressed mathematically, which uses the law of connected vessels, bouncy principle, forces equilibrium condition, and the photo elasticity of Fiber Bragg Grating (FBG). Thirdly, the proposed DSM sensors are applied to a repaired earthquake damaged bridge. Two-year data is collected and analyzed for studying the behavior and stability of the box girders. Additionally, a loading test on some bridge spans is carried out and the responses of the DSM sensors are compared with other temporal measurement instruments. Finally, from the two-year monitoring experience, it is concluded that the proposed DSM sensors are reliable and precise to monitor the behavior of multiple-span bridges. It is concluded the proposed DSM sensor could be the basic sensors in bridges for saving the labor work for the conventional leveling survey.
Zheng-Kuan Lee
bridge safety monitoring, FBG, prestress concrete beam, settlement sensor
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SE10-012
11:20
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11:35
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Employment of Vibration-Based Scour Detection Technology in a Field Application
Scour is one of the main causes of bridge failure. In order to develop a reliable scour depth measure and monitor technology and thus enhance Taiwan’s water-related disaster prevention industry, the National Center for Research on Earthquake Engineering has contributed tremendous efforts and developed a reliable approach for real-time bridge scour depth detection. The developed scour detection system integrates Micro-Electro-Mechanical-System (MEMS) based sensing technology and hydrological inspection technology, combining with technology of internet of things for scour detection. Being employed in a couple of bridge scour monitoring cases, and the reliability and performance of the developed system have been tested and verified. This paper presents a field application case to thoroughly introduce the design of the developed scour monitoring system, the manufacture and installation of the system at a particular bridge site, and the conducted analyses of the real-time data acquired from remote monitoring of scour.
Kuo-Chun Chang, Xiao-Qin Liu, Yung-Bin Lin
bridge scour, field application, MEMS-based sensing technology, scour monitoring, water level and flow velocity monitoring
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SE10-013
11:35
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11:50
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A FIELD MONITORING SYSTEM FOR MAINTENANCE AND MANAGEMENT OF EXTRADOSED BRIDGES
Extradosed bridge combines the structural elements of both a prestressed box girder bridge and a cable-stayed bridge, due to the structural characteristics which need more attention and consideration on the maintenance and management during the service life of such a specific bridge type. This paper presents a field monitoring system developed and built while the monitored bridge under construction. The primary purpose of the system is to provide the information for long-term maintenance and management of extradosed bridges. The system integrates varied types of sensors, such as tiltmeters, displacement meters, vibration-based cable force sensors, displacement settlement sensors, and environmental sensors. The daily changes of the declination of pylons, the distance of the expansion joints gap, the representative frequencies used to evaluate the force of each cable and the elevation of bridge deck are monitored and recorded by the developed system. In order to provide a benchmark record of structural behavior before the bridge opened to traffic and verify the performance of the developed system in the field, the loading tests were conducted before the opening of bridges. The field tests data is used to calibrate the analytical parameters of bridge models and help to define the initial values of the monitoring system. Thus, the analysis of structural parameters and responses are used to feedback result in field measurement work. Then the authorities can refer the monitored information to appropriately draw up the suggestions and the strategy of maintenance and management of the related bridges.
Yu-Chi Sung, Chun-Chung Chen, Zheng-Kuan Lee
bridge management, extradosed bridges, long-term monitoring system
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SE10-014
11:50
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12:05
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MONITORING BRIDGE SCOUR USING MACHINE LEARNING
With special characteristics of rivers, such as steep slope and rapid flow, bridge scour is an important safety issue in Taiwan. To ensure the stability and serviceability of bridge structure and to develop early warning in advance during hazard-prone rainfall, the relationship between heavy rainfall events and local scour around bridge piers needs to be resolved. In the era of internet of things, different kinds of real-time monitoring techniques open the gateway to measure field data instantly and precisely. It is thus impetus to develop a predictive model of scour depth based on these data. In this study, the dataset including flow rate, water level and signal of scour sensor of Zhuoshui River at Ziqiang Bridge is used to train and validate the deep learning neural network model. Scour depth predicted by the model is in a good agreement with the ground truth. In addition, the predictive model captures the moment when the peak value of scour depth occurred.
Yi-Hsiang Chen, Shih-Sheng Chang, Shu-Wei Chang, Chia-Ming Chang, Yung-Bin Lin, Kuo-Chun Chang, Chuin-Shan Chen
Artificial Neural Network, bridge, deep learning, monitor, scour
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