Integrating WRc and CERIU condition assessment models and classification protocols for sewer pipelines

Adoption of a suitable sewer pipeline condition classification protocol is recognized as an indispensable first step in worldwide sewer rehabilitation industry. Various condition classification systems for sewers have been developed in this regard. These systems differ according to local requirements in which no integrated and unified sewer condition assessment protocol is available. Therefore, an urgent need exists to develop standardized sewer condition assessment procedures. The presented research in this paper aims to review the historical development of different sewer condition classification protocols and develop a combined condition index (CCI) for sewers that integrates the combined effect of structural and operational conditions. To achieve these objectives, unsupervised neural network models have been developed. The CCI is divided into five condition categories ranging from "acceptable" to "critical." An unsupervised, self-organizing, neural network approach is also used to develop the CCI. The opinion of municipal practitioners is utilized to verify the CCI and integrated protocol. The developed integrated models and protocols will assist municipal engineers in developing a unified sewer condition assessment system. An unsupervised neural network methodology is adapted for integrating sewer condition assessment protocols and developing the CCI of sewer pipelines. The protocols developed by the Water Research Centre (WRc), United Kingdom, and the Centre for Expertise and Research on Infrastructures in Urban Areas (CERIU), Canada, have been used for the modeling process.