Abstract: In order to reinforce a cylindrical pipeline, in particular an underground water supply pipeline, prestressing reinforcements are placed and tensioned around it. In a zone where the pipeline has a radial projection, for example providing a manhole for access to the inside of the pipeline, the prestressing reinforcements are deflected to bypass the radial projection so that the reinforcements, located in the same layer on a side of the pipeline opposite the side having the projection, are distributed in a plurality of layers on this side having the protuberance.

Abstract: The invention concerns a method for repairing a pressurised fluid supply pipeline (1) comprising a series of buried prestressed concrete pipe segments (2, 3, 4) which consists in: providing excavations in the trench, beneath suitably set portions (6, 7) of the pipe (1), cleaning up said pipe portions, installing and tensioning the prestressed reinforcements (12) around said portions of the pipe and filling up the excavations with earth material by compacting said material.

Abstract: The invention addresses the problem of demounting a prestressing cable having a sheath, tendon extending in the sheath and tensioned between two anchoring devices, and a hardened material filling the sheath around the tendons. An energy dissipation device is installed between a zone of the structure and an accessible portion of the cable. The energy dissipation device has a first end applied to a bearing zone and a second end. It is suitable for limiting the force to which it is subjected as a function of the speed of relative displacement between its first and second ends. A first member for retaining the cable is arranged adjacent to the aforesaid portion of the cable. This portion is clamped in a second retaining member engaging the sheath and connected to the second end of the energy dissipation device. The cable can then be severed between the first and second retaining members.

Abstract: The invention addresses the problem of demounting a prestressing cable having a sheath, tendon extending in the sheath and tensioned between two anchoring devices, and a hardened material filling the sheath around the tendons. An energy dissipation device is installed between a zone of the structure and an accessible portion of the cable. The energy dissipation device has a first end applied to a bearing zone and a second end. It is suitable for limiting the force to which it is subjected as a function of the speed of relative displacement between its first and second ends. A first member for retaining the cable is arranged adjacent to the aforesaid portion of the cable. This portion is clamped in a second retaining member engaging the sheath and connected to the second end of the energy dissipation device. The cable can then be severed between the first and second retaining members.