Radar Interferometry Time Series to Investigate Deformation of Soft Clay Subgrade Settlement—A Case Study of Lungui Highway, China

Abstract

Monitoring surface movement near highways over soft clay subgrades is fundamental for understanding the dynamics of the settlement process and preventing hazards. Earlier studies have demonstrated the accuracy and cost-effectiveness of using time series radar interferometry (InSAR) technique to measure the ground deformation. However, the accuracy of the advanced differential InSAR techniques, including short baseline subset (SBAS) InSAR, is limited by the temporal deformation models used. In this study, a comparison of four widely used time series deformation models in InSAR, namely Multi Velocity Model (MVM), Permanent Velocity Model (PVM), Seasonal Model (SM) and Cubic Polynomial Model (CPM), was conducted to measure the long-term ground deformation after the construction of road embankment over soft clay subgrade. SBAS-InSAR technique with TerraSAR-X satellite imagery were conducted to generate the time series deformation data over the studied highway. In the experiments, three accuracy indices were applied to show the residual phase, mean temporal coherence and the RMS of high-pass deformation, respectively. In addition, the derived time series deformation maps of the highway based on the four selected models and 17 TerraSAR-X images acquired from June 2014 to November 2015 were compared. The leveling data was also used to validate the experimental results. Our results suggested the Seasonal Model is the most suitable model for the selected study site. Consequently, we analyzed two bridges in detail and three single points distributed near the highway. Compared with the ground leveling deformation measurements and results of other models, SM showed better consistency, with the accuracy of deformation to be ±7 mm.

Time Series Deformation Monitoring over Large Infrastructures around Dongting Lake Using X-Band PSI with a Combined Thermal Expansion and Seasonal Model

“…In order to compensate for the unavailability of the external in situ deformation measurements over this area, the residual phase of each interferogram obtained through the TESM was compared with that of LM. According to [31], the fitting accuracy of a deformation model can be reflected by the residue phase (Δϕres in equation ( 1)). The smaller the residual phase is, the higher the accuracy of the selected model is.…”

Mining-Induced Time-Series Deformation Investigation Based on SBAS-InSAR Technique: A Case Study of Drilling Water Solution Rock Salt Mine

“…The deformation component ∆d is of the main interest. The functional relationship between ∆d and the deformation parameters can be written as [25]…”

Can Machine Learning and PS-InSAR Reliably Stand in for Road Profilometric Surveys?

“…The high capabilities of SAR sensors in terms of measurement reliability, accuracy, speed of execution, high coverage, and the possibility of data processing in near real-time and back in time have meant a bursting development of SAR-based products as high-performance NDT in monitoring and inspection activities of linear infrastructures. In the literature, there are several SAR-based applications, mainly PS-InSAR surveys, of infrastructure monitoring activities, e.g., road infrastructures [ 6 , 7 , 8 , 31 , 32 , 33 , 34 , 35 ], rail infrastructures [ 36 , 37 , 38 , 39 , 40 ], airport runways [ 41 ], and bridges [ 42 , 43 , 44 , 45 ]. In these research studies, the common objective is to identify critical infrastructural sections by processing SAR images and comparing these surveys with other techniques (e.g., leveling or GPS surveys).…”

“…In these research studies, the common objective is to identify critical infrastructural sections by processing SAR images and comparing these surveys with other techniques (e.g., leveling or GPS surveys). Furthermore, research has focused on planning activities of infrastructures, exploiting radar interferometry to recognize areas in which it is more appropriate to build infrastructures [ 35 ], and research on prevention activities, where the PS-InSAR survey is inserted in a Pavement Management System perspective [ 32 ].…”