Integrated InSAR monitoring and structural assessment of tunnelling‐induced building deformations

Abstract

Summary Structural deformation monitoring is crucial for the identification of early signs of tunnelling‐induced damage to adjacent structures and for the improvement of current damage assessment procedures. Satellite multi‐temporal interferometric synthetic aperture radar (MT‐InSAR) techniques enable measurement of building displacements over time with millimetre‐scale accuracy. Compared to traditional ground‐based monitoring, MT‐InSAR can yield denser and cheaper building observations, representing a cost‐effective monitoring tool. However, without integrating MT‐InSAR techniques and structural assessment, the potential of InSAR monitoring cannot be fully exploited. This integration is particularly demanding for large construction projects, where big datasets need to be processed. In this paper, we present a new automated methodology that integrates MT‐InSAR‐based building deformations and damage assessment procedures to evaluate settlement‐induced damage to buildings adjacent to tunnel excavations. The developed methodology was applied to the buildings along an 8‐km segment of the Crossrail tunnel route in London, using COSMO‐SkyMed MT‐InSAR data from 2011 to 2015. The methodology enabled the identification of damage levels for 858 buildings along the Crossrail twin tunnels, providing an unprecedented number of high quality field observations for building response to settlements. The proposed methodology can be used to improve current damage assessment procedures, for the benefit of future underground excavation projects in urban areas.

Monitoring deformations of infrastructure networks: A fully automated GIS integration and analysis of InSAR time-series

“…The application of MT-InSAR techniques to real case studies and the cross-validation of PS-based results against in-situ measurements have demonstrated the reliability of this approach for health monitoring of different types of assets. Surface deformations can be effectively extracted for individual objects, such as buildings, 30,31,[37][38][39][40]78,79 or linear infrastructure, such as railways, 32,33,80,81 roadways, 56,57,[82][83][84] levees 85,86 and coastal structures. 55 Previous studies have shown the feasibility of these techniques for monitoring the settlement of bridge piers 87 and the structural deformations of bridges.…”

“…In more recent work, 33,34,38,[103][104][105][106] InSAR-derived results from different type of structures have been compared with measurements gathered by in-situ instruments and visual inspections, revealing good agreement between the data and enabling the integration of MT-InSAR measurements with damage assessment procedures. 38,39,[107][108][109][110] However, while these studies demonstrate the potential of MT-InSAR for infrastructure monitoring, handling the large amount of PS data for civil engineering applications is still a challenge. A significant part of the postprocessing phase usually takes place using GIS, with the aim of merging the PS data and geospatial databases related to the structures within the monitored area.…”

“…In more recent work, 33,34,38,103–106 InSAR-derived results from different type of structures have been compared with measurements gathered by in-situ instruments and visual inspections, revealing good agreement between the data and enabling the integration of MT-InSAR measurements with damage assessment procedures. 38,39,107–110…”

“…This makes MT-InSAR techniques an excellent tool for detecting deformations over built-up areas [29][30][31] and civil infrastructure. 15,18,[32][33][34] Recent studies have shown the feasibility of space-borne MT-InSAR techniques to provide accurate spatial information for building monitoring, [35][36][37][38][39][40][41][42][43][44] bridges, 16,45,46 dams, [47][48][49][50] railways [51][52][53][54] and other linear infrastructure, [55][56][57][58][59] demonstrating that remote-sensing data can be effectively utilised in combination with conventional ground-based monitoring systems, such as precise levellings and automated total stations. However, the information obtained from MT-InSAR analysis typically consists of a huge amount of data.…”

“…Geographic Information Systems (GIS) facilitate the integrated analysis of large volumes of multi-disciplinary data, allowing the integration of remote-sensing measurements and civil engineering assessment procedures. 16,39,57,[60][61][62][63] To facilitate a preliminary identification of the most vulnerable infrastructure assets or critical locations along linear infrastructure systems, a methodology based on the fully automated integration of MT-InSAR data and a GIS-based analysis is presented in this paper. The proposed methodology automatically processes large volumes of PS displacement timeseries and road network databases to extract deformation data over a given network, and performs local deformation analysis designed to detect anomalous differential movements between parts of the same piece of infrastructure.…”