Continuous GPS Monitoring of Structural Deformation at Pacoima Dam, California

Abstract

INTRODUCTION In September 1995, a system of three continuously operating GPS receivers was deployed to monitor the displacements of Pacoima Dam relative to a stable station nearby at Fire Camp 9 (2.5 km away). The dam has been monitored in near real-time for over two years through a joint effort of the U.S. Geological Survey (USGS) and the County of Los Angeles, making use of the network infrastructure of the Southern California Integrated GPS Network (SCIGN). This study demonstrates the feasibility of effective and timely monitoring of engineered structures using the Global Positioning System (GPS). In much the same way that strong-motion seismic recording instruments have made essential contributions to engineers' understanding of structural response to earthquake shaking, precise measurements of a structure's static displacements can indicate subtle damage that could be of concern for public safety. Conventional surveying methods have been used in the past to monitor static displacements...