Table of Contents

Pipeline Condition Assessment




Pipe failures occur when the pipe cannot contain the fluid internally within the pipe–either the strength is too low (from wrong material selection, fatigue, stress corrosion, etc.) or the stress is too high (overloads, loss of wall thickness etc.) resulting in an interference zone between loads and strengths. Such factors lead to condition deterioration of pipelines. While the pipe is above ground such failures are assessable but if the pipe is underground its condition assessment is a difficult process and at times almost impossible. Another point to remember is that the condition deterioration is a continuous process which gets accelerates with the age and other external or internal conditions. So a pipe with a small crack one day can be a completely collapsed pipe five years down the line. This process can be arrested with proper repair and maintenance on a regular basis. The decision to repair and maintain heavily banks upon the present condition and therefore the need to assess the pipe condition.


Present day subsurface networks in India are leading the life of neglect since they are out of sight as well as mind. Networks are dogged with the situations of Hydraulic Failures, Structural Failures, Environmental Failures, & Operational Failures on a regular basis and need substantial repairs and maintenance actions to contain the situations. Ways and means to assess their conditions are, in the first place not applied and even if applied are too simplistic where the results are just suspect. Present day repair and maintenance of subsurface pipelines is mostly of emergency nature where the maintenance is done only to repair the damaged parts. This practice needs to be changed and a system to evaluate the pipeline condition on a regular basis needs to be evolved. Non – destructive and non – invasive condition assessment methods play a vital role in such project planning and execution and therefore quite important.


The compilation in your hands discusses some of such methods where the subsurface pipelines are assessed on the basic engineering principles like direct and indirect assessments methods. Condition grading and recording is another important facet of condition assessment process as without them it is almost impossible to conclude the assessment process and thereafter the rehabilitation or renewal process.


Importance of these methods to Trenchless fraternity is quite obvious since two of the major sectors of Trenchless Industry viz. rehabilitation and renewal are dependent entirely on the findings of condition assessment process and therefore this compilation.


Intent of this book is to provide the readers with the information about all the above issues so that they are better equipped to deal with the pipeline failures, consequences of failures and their management cycle. Information provided here is only of informative nature. As the methods discussed herein are specialized processes it is advisable to consult experts prior to applying any of these methods as they may or may not be suitable for any given set of parameters connected to any particular pipeline. The principles behind the process are dealt herewith but the complete analysis would need a deeper study.



Prof Niranjan Swarup

Executive Director

Indian Society for Trenchless Technology



Table of Contents



Pipeline Failures

01 – 12


Uniform Defect Codes

13 – 22


Subsurface Utility Engineering

23 – 32


Review of Pipe Failure Detection & Location Techniques

33 – 46


Direct Condition Assessment Methods

47 – 58


Indirect Condition Assessment Methods

59 – 64


Network Condition Survey & Recording

65 – 120


Safety Issues

121 – 152


Life Cycle of Subsurface Networks

153 – 166


Sewer System Evaluation & Management

167 – 172


References & Acknowledgements

173 – 174


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