This study assesses ground subsidence and surface angular distortion along the Lerma–Zinacantepec segment of the Mexico-Toluca Intercity Railway. A multitemporal Interferometric Synthetic Aperture Radar (InSAR) framework using the Short Baseline Subset (SBAS) algorithm processed Sentinel-1 imagery (2022–2024), validated against the MXTO Global Navigation Satellite Systems (GNSS) station ($R^2$ of 0.86 and 0.80 for descending and ascending tracks, respectively). Kinematic vector decomposition revealed a mean vertical ground subsidence rate of −2 cm/year. To evaluate geohazard susceptibility, angular distortion was computed from these decomposed vertical displacements using a fixed 160 m spatial baseline. By explicitly integrating intrinsic InSAR measurement uncertainty into the classification, localized steep gradients initially flagged by mathematical models were discarded as statistically negligible artifacts. Consequently, results show widespread ground stability, with the evaluated 16-km segment falling within low-risk thresholds. Corroborating this, in-situ visual inspections revealed no structural damage induced by differential subsidence. Due to Sentinel-1 pixel-mixing limitations, the measured signals represent ground subsidence rather than direct structural deformation. Future monitoring should integrate higher-resolution SAR sensors or localized structural health instrumentation to isolate the behavior of the railway superstructure from regional subsidence.

In this paper, a practical application of Interferometric Synthetic Aperture Radar (InSAR) technology is implemented in the structural health monitoring (SHM) of bridges. The structural performance and risk assessment of the El Carrizo Bridge, a cable-stayed bridge that suffered severe structural damage due to a vehicular accident back in 2018, are presented. The structure is characterized by a total length of 487 m and a main span of approximately 218 m. The bridge's displacements were monitored using satellite-based InSAR technology. Then, time-series displacement data were analyzed to interpret the structural response during the post-rehabilitation period. Finally, the results indicate that the bridge currently maintains normal operational performance with no identified risks. In summary, InSAR offers a unique, remote approach to evaluating bridge performance through satellite imagery. This technology represents a cost-effective and non-intrusive alternative to traditional in situ sensors, such as accelerometers, gyroscopes, linear variable differential transformers, and strain gauges, which require physical installation/operation and manual maintenance.

Existing bridges represent a significant challenge for structural engineering due to aging, increased traffic demands, and lack of original design information. This paper presents an investigation of the structural behavior of the Miguel Hidalgo Bridge, located in Culiacán, Sinaloa, México, which has remained in service for over a century. A preliminary visual inspection identified deterioration mechanisms, including cracking, exposed reinforcement, damaged bearings, and localized structural deformations. Given the absence of original design documentation, a structural health monitoring (SHM) strategy was implemented to assess its condition. The SHM methodology integrates field instrumentation using accelerometers for operational modal analysis under ambient vibration and GPS receivers for displacement measurements, complemented by a geometric survey and material characterization through non-destructive techniques. These data were used to develop and calibrate a three-dimensional finite element (FE) model, which was employed to evaluate structural performance under service loads in accordance with AASHTO provisions. Results indicate that the bridge satisfies serviceability criteria; however, certain components exhibit deficiencies in load-carrying capacity. These findings highlight the importance of integrating monitoring data with numerical modeling to support decision-making related to maintenance, rehabilitation, and extension of service life in existing bridge infrastructure.