Case studies

The Great Man Made River project in Libya includes an extensive system of prestressed concrete cylinder pipe (PCCP) of different configurations constructed over a number of years. Severe corrosion activity has been discovered in parts of the pipeline that has led to concerns about the long-term integrity of the pipeline.
In order to get the best and most reliable information on each pipe’s actual condition, the Great Made Man River Authority very early implemented the latest monitoring technologies available on the market such as acoustic monitoring, electromagnetic inspection.

Aware of the need for anticipating the potential deterioration of each pipe section to develop a cost-efficient and long-term maintenance strategy, the Authority decided in 2003 to get an engineering and management tool to ensure the following functions:

• Classification of each pipe section in one of the five pre-determined deterioration categories to prioritise inspection, monitoring & repair.
• Determination of an initial estimation of theoretical remaining life of each pipe section, using known information about the properties of the pipe.
• Adjustment of the remaining life estimation for pipe sections using information provided by visual inspection, acoustic monitoring, remote field eddy current surveys, corrosion surveys and other methods.

Built on a comprehensive database continuously updated of all relevant information on pipe and soil properties, on operation constraints, monitoring and visual inspections, the system will give to GMRA reliable information to anticipate unexpected important repair cost and implement a powerful preventive maintenance strategy.