Abstract: The invention relates to a device (10) for detecting and locating fluid leakage from a hydraulic work, the device being characterized in that it comprises a geotextile fabric (12) made of yarns or fibers and provided with: at least one first optical cable (14) in contact with said geotextile (12) and formed by a protective tube within which at least one multimode optical fiber (141) is placed, said multimode optical fiber (141) being suitable for detecting a temperature variation and transmitting a signal that is modified when temperature varies and at least one second optical cable formed by a sheath receiving tightly at least one monomode optical fiber (142) suitable for detecting a deformation of the geotextile (12) and for transmitting a signal that is modified when the deformation is detected in that said second optical cable being bonded to the geotextile (12). The invention is applicable to detecting and locating leakage from hydraulic works.

Abstract: The invention relates to a device (10) for detecting and locating fluid leakage from a hydraulic work, the device being characterized in that it comprises a geotextile fabric (12) made of yarns or fibers and provided with: at least one first optical cable (14) in contact with said geotextile (12) and formed by a protective tube within which at least one multimode optical fiber (141) is placed, said multimode optical fiber (141) being suitable for detecting a temperature variation and transmitting a signal that is modified when temperature varies and at least one second optical cable formed by a sheath receiving tightly at least one monomode optical fiber (142) suitable for detecting a deformation of the geotextile (12) and for transmitting a signal that is modified when the deformation is detected in that said second optical being bonded to the geotextile (12). The invention is applicable to detecting and locating leakage from hydraulic works.

Abstract: A process for locating and measuring deformation in a civil engineering structure wherein at least one geosynthetic fabric (1) containing a plurality of optical fibers (2a to 2e) in parallel and capable of transmitting signals is applied in the structure or under the structure. The optical fibers contain Bragg gratings (3), evenly spaced in series (4) of N1 consecutive gratings that correspond to the same wavelength. The series is distributed in identical sets, each of which contains N2 consecutive series that correspond to the different wavelengths, and, in at least two optical fibers, the numbers N1 of gratings of a series and the numbers N2 of series (4) of a set (5) are determined to locate the deformations to which the structure is subjected on the one hand and, on the other, to measure the elongation of the said optical fibers where the deformation occurs.

Abstract: The invention concerns a process for locating and measuring deformation in a civil engineering structure, characterised by the fact that at least one geosynthetic fabric (1) containing a plurality of optical fibres (2a to 2e) in parallel and capable of transmitting signals is applied in the said structure or under the said structure, the said optical fibres containing Bragg gratings (3), evenly spaced in series (4) of N1 consecutive gratings that correspond to the same wavelength, the said series being themselves distributed in identical sets, each of which contains N2 consecutive series that correspond to the different wavelengths, and by the fact that, in at least two optical fibres, the numbers N1 of gratings of a series and the numbers N2 of series (4) of a set (5) are determined in such as way that the measurement of the differences between the wavelengths of the incident light transmitted in each of the said optical fibres and the wavelengths of the light reflected by the Bragg gratings enable to locat