Deformation monitoring and analysis of the thermal expansion of high-rise buildings in Shanghai Lujiazui using tomography-based persistent scatterer interferometry

We utilize a tomography-based persistent scatterer interferometric synthetic aperture radar (Tomo-PSInSAR) approach for monitoring the deformation performance and analysis of the thermal expansion of 33 high-rise buildings in Shanghai Lujiazui. For the purpose of this study, we use 31 stripmap acquisitions from TerraSAR-X missions spanning from December 2009 to February 2013. Considering that thermal expansion, concrete creep, and shrinkage are three long-term movements that occur in high-rise buildings with concrete structures, we use an extended 4-D SAR phase model, and three parameters (height, deformation velocity, and thermal amplitude) are estimated simultaneously. Additionally, we apply a two-tier network strategy to detect single and double PSs with no need for preliminary removal of the atmospheric phase screen in the study area. The thermal amplitude map demonstrates that the derived thermal amplitude of the buildings is highly related to the building height due to the upward accumulative effect of thermal expansion. The deformation velocity map reveals that the Shanghai World Financial Center is subject to a great deal of deformation during the newly built period due to concrete creep and shrinkage effects, which are height-dependent downward movements. In addition, the deformation rates caused by concrete creep and shrinkage are largest at the beginning and gradually decrease, finally achieving a steady state as time goes to infinity. In contrast, the deformation velocity map shows that the Jin Mao Tower is almost stable during this period. We observe a negative correlation between deformation characteristics and the time of completion of high-rise buildings, inferring that the newly built concrete buildings are more sensitive to concrete creep and shrinkage effects than the older concrete buildings. Our study emphasizes the potential of the Tomo-PSInSAR solution for monitoring the deformation performance and analysis of the thermal expansion of high-rise buildings.