Comparison of Four Sewer Condition Assessment Protocols Based on Field Data

In order to better plan new or update sewer pipe condition assessment protocols, this paper presents systematic comparisons of four of the most widely used sewer condition assessment protocols, including the fourth edition of the Sewer Rehabilitation Manual (SRM-4) in the UK, the Pipeline Assessment and Certification Program (PACP) in America, the Sewer Physical Condition Grading Protocols (SPCCM) in Canada, and the Technical Specification for Inspection and Evaluation of Urban Sewer (TSIEUR) in China. In the qualitative comparison, the defects categories, deduct values, and assessment methods of the four protocols are analyzed. A new concept of defect weight is firstly introduced to make comparisons between protocols applicable and easy; in the quantitative comparison, the protocols are used to evaluate the same 182 sewer pipe segments based on field data and the assessment results are compared. It is found that the main reasons for the different evaluation results are due to the different defect weights and evaluation methods used. Finally, PACP shows obvious advantages and is recommended for asset managers when making new or updating protocols in the future.