The construction of underground works (new metro lines. burial of railway lines) may affect the underground water flow and the elevation of the phreatic surface because of the introduction of previously inexistent barriers to the flow. Particularly in urban areas, these changes must be controlled to avoid flooding of basements, differential settlements, cracking in structures, etc.
Principia has carried out this type of studies for new metro lines in cities like Valencia and Sevilla, burial of railway lines in Logroño, Oliva, Costa del Sol, etc., the expansion of the Port of Tarragona, and urban tunnels like that under Plaza de Colón in Barcelona.
The figures show an example. The fist one shows, for one of the cases studied, the expected changes in the phreatic surface in the absence of corrective measures; the second one corresponds to the same case, but after introducing some measures to mitigate the barrier effects to the flow crested by the construction.
