An analysis of the categories regarding the probability of an operational failure of sewers

摘要

The aim of the paper is to present proposals for the determination of the operational failure probability categories of sewers. It includes the results of a review of eleven classifications for assessing the technical condition of sewer pipes used in some countries in Europe, North America, Asia and Australia. The result of the analysis is to indicate differences between the recommendations formulated in the guidelines, resulting from the types of defects and the accepted classes. The key conclusion highlights that the application of different classification methods to assess the operational state of sewer pipes contributes to the receiving of discrepancies in their assessment. Consequently, different priorities are indicated for subsequent inspection and maintenance as well as contradictory forecasts of potential failures. The original element of the work is to present discrepancies in the assessment of three types of defects (roots, sediments, protruding connections) occurring in sewers, assessed according to selected classifications, as well as proving the necessity to undertake work aimed at determining correct recommendations, and enabling a reliable assessment of the operational condition.