Subsidence caused by Line 7B of Madrid Subway

The Line 7B of the subway of Madrid was inaugurated in May 2007. Since then, it has been fully or partially closed on multiple occasions (almost 3 years in total out of the 15 it has been in operation).

In addition, dozens of homes have been affected, buildings demolished, and many people evacuated from their homes. The economic cost of rehabilitating buildings, relocating people, and carrying out various interventions to remedy the situation has been very high.

Subsidence of the line 7B of the Madrid Metro

In these situations, satellite InSAR technology can provide valuable information. Knowing and objectively quantifying building-by-building damage at any given time is key to making the best decisions in any of the areas of intervention.

Detektia has analyzed the deformations of all buildings in an extensive area around the tunnel route from 2015 to 2021. During this period, despite more than 8 years having passed since the completion of the works, significant deformations and damage are observed in numerous buildings.

The structural health indices derived from the InSAR results allow each building to be classified according to its degree of damage. We have generated indices that quantify differential settlements and deformations, which are what cause cracks and damage to buildings. These indices objectively quantify the structural health of all buildings in an extensive area.

If we delve further into the information, the deformation time series show the exact moment when the damage began, allowing for the precise measurement of the deformations suffered by a specific building to the millimeter.

Displacement of buildings in San Fernando de Henares (Madrid) due to Madrid Metro works on Line 7B

In San Fernando de Henares more than 600 houses have been affected by the works of line 7b. Some buildings have been demolished due to the serious risk of collapse.