| The measurement of exterior deformation is one of the most important measuring items for safety management of embankment dams. By using targets installed on the crest and slopes of embankment dams, their exterior deformation has been measured by conventional surveying methods. According to the Japanese dam safety management standard, the measurement frequency of exterior deformation of embankment dams is set as once a week at the period of the first filling of reservoir, that is, the first term of dam management, and once every three months in the third term that is the final management stage when behavior of the dam and its foundation come to be stable. But, because the surveying work is relatively time consuming one, rapidly responding after a large earthquake or in other emergencies is a big challenge.The global positioning system (GPS) is a system that can perform surveys quickly in relatively low cost. GPS is a weather-proof positioning system using satellites that is well known for its role in car navigation and in surveying applications.The results of our previous research made it clear that we should investigate how to install GPS sensors on the crest in order to fully introduce GPS sensors as the method of measuring exterior deformation of embankment dams. In this research, we develop the backfill type GPS sensors, and make the verification test for them. |
