A study conducted by the University of Miami has revealed that 35 skyscrapers located on Miami’s barrier islands, including Porsche Design Tower, Faena Hotel, and Trump Tower III, have experienced sinking, or “subsidence,” of up to eight centimetres since 2016. The buildings are situated in the popular coastal regions of Miami Beach, Surfside, Bal Harbor, and Sunny Isles Beach.
The research, which took place over a seven-year period, utilised the Interferometric Synthetic Aperture Radar (InSAR) to measure even the smallest geological shifts. The study found that approximately half of the affected buildings were constructed after 2014, with many showing ongoing subsidence, suggesting a correlation with construction activities.
Causes and Effects of Subsidence
The sinking is attributed to the combination of inconsistent limestone layers and natural groundwater movements, which the study suggests could be worsened by construction activity. According to the researchers, load-induced deformation from construction projects accelerates the geological changes beneath the buildings.
“We attribute the observed subsidence to load-induced, prolonged creep deformation of the sandy layers within the limestone, which is accelerated, if not instigated, by construction activities,” the study stated.
Despite the natural expectation that buildings may settle over time, the uneven sinking observed on these structures is a significant concern. Differential settlement, where parts of the ground sink at different rates, could lead to structural stress, potentially causing long-term damage to the buildings.
Impact on the Community and Further Concerns
The study, which follows the 2021 collapse of the Champlain South Condominium Tower in Surfside, which tragically killed 98 people, underscores the importance of ongoing monitoring for buildings in this region. While the study could not confirm whether subsidence contributed to the collapse, it highlighted the need for enhanced surveillance, particularly in coastal areas prone to corrosion and shifting ground conditions.
“The collapse of Champlain Tower has highlighted the need for monitoring of building stability, especially in coastal areas with corrosive environmental conditions,” the report noted.
Skyscrapers Continue to Rise Despite Risks
While the study provides a cautionary tale, construction continues unabated. Arquitectonica, for example, recently completed the 48-storey Five Park skyscraper in Miami Beach, the tallest building in the city. Additionally, Kengo Kuma and Associates is designing an 18-storey Aman residential tower in the area. Even amid the challenges posed by sinking and rising sea levels, new projects are being pushed forward.
Further research has also pointed to similar issues in Manhattan, where skyscrapers are contributing to the city’s sinking. This growing concern raises questions about the sustainability of high-rise buildings in areas with unstable ground conditions.