Stability assessment of high-speed railway using advanced InSAR technique

High-speed railways play important roles in connecting populated cities. Strict attention to ground subsidence is applied to ensure its transportation safety. Shanghai-Hangzhou high-speed railway is an important part of China's “Four Vertical and Four Horizontal” Passenger Line Network. In this study, TerraSAR-X and ASAR images were employed to recover the surface evolution along the high-speed railway using advanced InSAR technique. A spatial-temporal criterion is updated for PS identification. Nonlinear deformation is modeled and removed by a linear least squares fit. Measurements from TSX and ASAR during a closer period as well as the transverse subsidence profiles showing a fairly consistent agreement. According to the longitudinal subsidence profiles, although the subsidence gradient now is within the guidelines of high-speed railway, the increasing cumulative subsidence can still be a potential threat for the line.