The present invention relates to a micropile or tie (10) for connecting a structure (5) to a soil (2), the micropile or tie comprising: - at least one linear metallic element (11), - at least one external corrosion-protective duct (14), inside which is positioned the linear metallic element (11), said external duct being filled with a hardening material, - a head element (20) threadly connected to an upper end (11a) of the linear metallic element (11), wherein the head element (20) is surrounded by a cover (27, 28) for protection against corrosion, said cover being sealed to the external duct (14) and being filled with a hardening material.