Reinforcement arrangement applicable to the connections of two sections of a power cable, which power cable is a single electric cable used to transmit electrical current at medium, high or extra-high voltage level and it may be installed inside a submarine energy cable, such as inside an umbilical cable, wherein each power cable end includes an inner conducting core end (11,11') of copper or aluminium with one or more concentric polymeric and metallic layers that constitute insulation, screens and covers (12,12'), and wherein the connections of the conducting core ends (11,11') are made by welding so forming a conducting cores welded area, characterised in that: - the reinforcement arrangement comprises a cylindrical body formed by two bodies with a half-round shape (14', 14'') or more than two bodies with round shapes, that are placed joined together and concentrically form a cylindrical body upon the conducting cores welded area of the cable and on the adjacent area of the outside covering of the cable (12,12'); wherein: - the round bodies (14', 14") are joined to the outer part of the cable splice through a structural adhesive; - each round body (14', 14") is made from at least one sheet, which: - is made from a material reinforced with fibres of great mechanical strength which are selected from the group of: carbon fibres, fibreglass, aramid fibres, fibres, graphene metallic fibres, and synthetic fibres, and also - comprises a resin made up of a polymeric matrix, loads, and additives for joining the fibers of great mechanical strength and also for being capable of shaping the structure of the round body; - the at least one sheet is shaped to have the round structure of the round bodies (14', 14''); and - the cylindrical body is of a thickness varying from 0.5 mm to 20 mm. - the reinforcement arrangement comprises a cylindrical body formed by two bodies with a half-round shape (14', 14'') or more than two bodies with round shapes, that are placed joined together and concentrically form a cylindrical body upon the conducting cores welded area of the cable and on the adjacent area of the outside covering of the cable (12,12'); wherein: - the round bodies (14', 14") are joined to the outer part of the cable splice through a structural adhesive; - each round body (14', 14") is made from at least one sheet, which: - is made from a material reinforced with fibres of great mechanical strength which are selected from the group of: carbon fibres, fibreglass, aramid fibres, fibres, graphene metallic fibres, and synthetic fibres, and also - comprises a resin made up of a polymeric matrix, loads, and additives for joining the fibers of great mechanical strength and also for being capable of shaping the structure of the round body; - the at least one sheet is shaped to have the round structure of the round bodies (14', 14''); and - the cylindrical body is of a thickness varying from 0.5 mm to 20 mm. - the round bodies (14', 14") are joined to the outer part of the cable splice through a structural adhesive; - each round body (14', 14") is made from at least one sheet, which: - is made from a material reinforced with fibres of great mechanical strength which are selected from the group of: carbon fibres, fibreglass, aramid fibres, fibres, graphene metallic fibres, and synthetic fibres, and also - comprises a resin made up of a polymeric matrix, loads, and additives for joining the fibers of great mechanical strength and also for being capable of shaping the structure of the round body; - the at least one sheet is shaped to have the round structure of the round bodies (14', 14''); and - the cylindrical body is of a thickness varying from 0.5 mm to 20 mm. - is made from a material reinforced with fibres of great mechanical strength which are selected from the group of: carbon fibres, fibreglass, aramid fibres, fibres, graphene metallic fibres, and synthetic fibres, and also - comprises a resin made up of a polymeric matrix, loads, and additives for joining the fibers of great mechanical strength and also for being capable of shaping the structure of the round body; - the at least one sheet is shaped to have the round structure of the round bodies (14', 14''); and - the cylindrical body is of a thickness varying from 0.5 mm to 20 mm.