Excavation, support and coating of the Leguizamón tunnel in Bolueta belonging to Line 1 of the Bilbao Metro at the “Bolueta – Etxebarri” section, 70 m² section and 130 m in length. Due to the unfavourable and conditions, the tunnel was excavated under the protection of successive micro pile shields, which were divided into 20 m sections, which were completed in a conical format, to allow completion of successive shields. Throughout the length of the tunnel heavy support was used, consisting in HEB-180 trusses every meter and Bernold sheets.
