Analysis of Railway Subgrade Settlement Deformation in Permafrost Regions Based on Satellite Interferometry

Abstract

SAR differential interferometry is an innovative space-based measurement technology for ground deformation. Under inclement Qinghai-Tibet plateau environment, monitoring and analysis of railway subgrade deformation using satellite interferometry in plateau permafrost region has very important engineering significance for stability evaluation and safety management. In the paper, a brief description of the principle and processing procedure of SAR differential interferometry was given, and the influencing parameters and error analysis were discussed. Then satellite interferometry was applied to measure subgrade deformation in the Beiluhe test site along the Qinghai- Tibet railway with gathered satellite interferometric SAR images. Based on the satellite-interferometry- derived data, the deformation characteristics of six points in different permafrost subgrades (the sliced rock embankment, the crushed rock embankment and railway bridge) along the Qinghai-Tibet railway were analyzed and compared. The analysis results show that settlement is the main behavior of railway subgrade deformation and the deformation amount of railway bridge is less than the sliced or the crushed rock embankment along the Qinghai-Tibet railway in permafrost regions. All these results are in good agreement with the ground measurements and other relevant studies.

Keywords

• Railway subgrade
• Settlement
• SAR differential interferometry
• Deformation monitoring
• Leveling.