Development Of GPS Deformation Monitoring System For Steep Slopes In The Xiaowan Hydropower Station

The stability of steep slopes has become a key technology problem of large hydropower constructions due to the special and complex environments of the terrain and geology in China. Traditional surveying methods for slopes deformation monitoring have been difficult to meet the requirements of current safety monitoring of the slopes for its out-of-date techniques, limitations in surroundings, high cost and poor automation. Global positioning system (GPS) has become one of the most advanced tools in the deformation monitoring for the advantages of high accuracy, real-time and all weather operations. However, there are still some problems on 3D positioning accuracy and high cost of deformation monitoring for slopes of the hydropower constructions. The paper describes the research background of steep slopes in Xiaowan hydropower station. The GPS multi-antenna method has been used to develop the long-rang automatic system for slope deformation monitoring in order to solve the problems on slopes deformation monitoring using GPS. The emphasis in this work has been placed on1. The investigation of the design scheme of long-rang automatic slope deformation monitoring system using GPS. The key parts include data acquisition, data transfer, data processing and deformation forecasting.2. The development of the methodology to process single epoch GPS observations for deformation surveys. The deformation model of slopes is established, and the method of the GPS single epoch positioning is used to avoid cycle slip detection and ambiguity resolution, so that the data processing procedure can be simplified greatly.3. The development of Kalman filtering for deformation analysis and deformation forecasting. Kalman filtering is used to estimate slope deformation using the continuous GPS observations.4. The development of the software program for the GPS multi-antenna controller. The software and hardware of the system have been tested. Programs are compiled by language C to implement the function of receiving and sending GPS binary data, and transmitting data from monitoring field to control center.5. The implementation of the steep slope deformation monitoring system for Xiaowan hydropower station using GPS positioning algorithm and software developed in this work. And the deformation information of slopes in 3D has been displayed directly.