Data di Pubblicazione:
2018
Citazione:
Displacement Monitoring and Health Evaluation of Two Bridges Using Sentinel-1 SAR Images / Q. Huang, O. Monserrat, M. Crosetto, B. Crippa, Y. Wang, J. Jiang, Y. Ding. - In: REMOTE SENSING. - ISSN 2072-4292. - 10:11(2018 Oct 10), p. 1714.
Abstract:
Displacement monitoring of large bridges is an important source of information
concerning their health state. In this paper, a procedure based on satellite Persistent Scatterer
Interferometry (PSI) data is presented to assess bridge health. The proposed approach periodically
assesses the displacements of a bridge in order to detect abnormal displacements at any position of
the bridge. To demonstrate its performances, the displacement characteristics of two bridges, the
Nanjing-Dashengguan High-speed Railway Bridge (NDHRB, 1272 m long) and the Nanjing-
Yangtze River Bridge (NYRB, 1576-m long), are studied. For this purpose, two independent
Sentinel-1 SAR datasets were used, covering a two-year period with 75 and 66 images, respectively,
providing very similar results. During the observed period, the two bridges underwent no actual
displacements: thermal dilation displacements were dominant. For NDHRB, the total thermal
dilation parameter from the PSI analysis was computed using the two different datasets; the
difference of the two computations was 0.09 mm/°C, which, assuming a temperature variation of 30
°C, corresponds to a discrepancy of 2.7 mm over the total bridge length. From the total thermal
dilation parameters, the coefficients of thermal expansion (CTE) were calculated, which were 11.26
× 10−6/°C and 11.19 × 10−6/°C, respectively. These values match the bridge metal properties. For
NYRB, the estimated CTE was 10.46 × 10−6/°C, which also matches the bridge metal properties (11.26
× 10−6/°C). Based on a statistical analysis of the PSI topographic errors of NDHRB, pixels on the
bridge deck were selected, and displacement models covering the entire NDHRB were established
using the two track datasets; the model was validated on the six piers with an absolute mean error
of 0.25 mm/°C. Finally, the health state of NDHRB was evaluated with four more images using the
estimated models, and no abnormal displacements were found.
Tipologia IRIS:
01 - Articolo su periodico
Keywords:
SAR interferometry; displacement monitoring; Sentinel-1; permanent scatterers; thermal
dilation; health monitoring
Elenco autori:
Q. Huang, O. Monserrat, M. Crosetto, B. Crippa, Y. Wang, J. Jiang, Y. Ding
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