Macdonald, B, Iannacone, JP, Falorni, G & Gianniaco, C 2015, 'InSAR-derived time series analysis of tunnel construction-induced ground deformation in urban landscapes', in PM Dight (ed.), FMGM 2015: Proceedings of the Ninth Symposium on Field Measurements in Geomechanics, Australian Centre for Geomechanics, Perth, pp. 315-328, https://doi.org/10.36487/ACG_rep/1508_19_Macdonald
(https://papers.acg.uwa.edu.au/p/1508_19_Macdonald/)
Abstract: Transportation corridors have reached capacity in many municipalities worldwide. To provide the extra capacity to serve growing populations, civic planners have turned to tunnelling for utility services and public transport. These tunnels are located under established urban and downtown core infrastructure. Tunnelling methods include cut-and-cover, traditional tunnel excavation and tunnel boring machines (TBM). Each method can have a different effect on the surface stability of the established in situ infrastructure depending on depth and substrate materials. Interferometric synthetic aperture radar (InSAR) is well suited to monitor the surface displacement resulting from these tunnelling activities. The advances in satellite radar coverage and InSAR processing techniques have led to millimetre accuracy in capturing ground displacement. City landscapes provide good radar targets with sample point densities ranging in the 10s of thousands per square kilometre without the need for ground instrumentation. Three tunnel monitoring case studies are presented showing monitoring of cut-and-cover, traditional excavation and TBM projects. The results over one metro line, one inter-urban rail line and one water utilities project are presented. InSAR provided an effective solution to analyse the evolution of the surface topography and the impact on infrastructure during the different stages of the tunnel projects. In each case, a strong spatial and temporal correlation between the settlement initiation and the timing of tunnel excavation was examined. The full coverage of the monitoring area also identified deformation in areas that were not adjacent to the excavation work, nor expected.