At present, China has about 100 thousand reservoirs and many of them aren’t installed with a safety monitoring system. Those reservoir dams, constructed on the foundation with complex geological structure and even geotechnical characteristics, have varied work behaviors and security statuses under the load effects and impact of natural factors. If any abnormality that happens isn’t identified in time, the results will be destructive. However, if effective measuring methods are adopted to supervise on those projects, any problem will be timely discovered and effective engineering measures will be further taken to prevent disasters. Dam accidents can result from many causes. After analyzing the causes of more than 300 dam accidents, it’s considered that 35% accidents are caused by the inadequate flood carrying capacity, as well as problematic computation and flood control capacity in the dam survey and design. Most of the cases are caused by engineering factors rather than the flood, and they could have been identified earlier with monitoring methods during the process from quantitative to qualitative change. A working dam has changeable engineering status and conditions constantly with the influence of various natural factors, so it’s necessary for comprehensive and systematic supervision the dam to look into the engineering status and analyze whether the dam, foundation and bank slope are running safely. With independently developed geophysical instruments, in combination with other sensors for rainfall, dam stress and deformation and water level, Geomative can effectively supervise on the dam body, the shore and the related facilities. While, through the observation of earth resistivity, the direct current electrical instrument could visually display such changes of water content in the soil as water level changes and seepage in the dam body, especially the internal pinhole leakage, which can be detected early. The system software can convert data concerning the change of resistivity into visualized charts with stratigraphic texture. Remote monitoring on the dam body can also be realized with network communication technologies. The Geomative online monitoring system for the reservoir dam body safeguards the safe operation of dams and reservoir areas.
The system is composed of the following modules:
Taiwan Hushan Reservoir is located in Douliu City and Gukeng Township of Yunlin County, about 10 km southeast of Douliu District. The water system is the upstream of Meilin Creek, a tributary of Beigang River with. The reservoir, as a medium-sized one, has a capacity of 53.47 million tons and a total catchment area of 6.58 square kilometers. The reservoir mainly supplies water for Yunlin, Nantou and Zhushan, with a daily water yield of 694,000 cubic meters. The establishment of the dam body monitoring system enables the continuous input of online monitoring data and real-time upload of such data to the cloud server center through the wireless network, which has realized remote monitoring of the reservoir. It facilitates the full, scientific and faithful presentation of dam seepage and provides a method for the real-time monitoring of Hushan Reservoir.
The online monitoring system in the project consists of sampling unit, control communication unit, data analysis and processing unit and client unit. The installation includes electrode, cable laying, equipment installation, line connection, network commissioning and parameter configuration.
After site surveys, the middle of Hushan Reservoir’s dam back was finally selected for the placement of the monitoring system in the project.
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