Abstract: The GPS displacement monitoring system is a new method for measuring ground surface displacements using Global Positioning System (GPS) technology. It can measure the three-dimensional displacements of multiple measurement points on the ground surface automatically and continuously. The present study applies the system for measuring the exterior deformation of two fill dams, namely, the Majimegawa Dam, a 21.9-meter-high earth-fill dam located in Yamaguchi Prefecture, Japan, and the Taiho Sub-dam, a 66.0-meter high rock-fill dam located in Okinawa Prefecture, Japan.This paper reports the observational results and verifies the effectiveness of the displacement monitoring system. From the observational results, we find that the GPS-based displacement measurement system was able to detect with high accuracy the very small movements that followed the changes in the water level of the reservoir and the compression of the dam core.

摘要： GPS位移监测系统是应用全球定位系统技术来测量地表位移的新方法。它能自动连续地测量地表多个测点的三维位移。本研究项目将GPS位移监测系统用于测量两座填筑坝的外部变形，即位于日本山口县的Majimegawa大坝和位于日本冲绳县的Taiho副坝。Majimegawa大坝是一座21.9 m高的土坝，而Taiho副坝是一座66.0 m高的堆石坝。文章呈列了观测成果，验证了该位移监测系统的有效性。从观测结果可见，基于GPS的位移测量系统能高精度地测量由水库水位变化引发的微小位移和大坝心墙的压缩变形。