A Guide for the Construction Inspection of Large Diameter Water Pipelines

摘要

The construction of large diameter pipelines is a large investment for any water utility. Achieving a quality construction project is critical to the overall performance and reliability of any water transmission system. Quality construction can also insure a longer service life for the pipeline. Therefore, the quality of the constructed pipeline is critical to the success of any water utility. The construction inspection of large diameter pipelines offers many challenges to the Owner's construction inspection teams. Large diameter pipelines typically use more complex pipe materials, bedding and backfill materials, appurtenances, corrosion protection requirements, and construction methods than do smaller diameter pipelines. Often the subtle differences between large diameter pipelines and small diameter pipelines are overlooked by inexperienced inspection teams. This paper includes an explanation of the critical components of large diameter pipeline inspection, and includes a convenient checklist for the field inspectors. The inspection checklist was developed from the author's pipeline design projects, as well as forensic engineering of pipeline failures. The paper focuses on the use of large diameter steel and concrete cylinder pipelines for water transmission service. The checklists cover important inspection and testing procedures such as: 1. Right-of-way clearing and restoration 2. Pipe handling 3. Pipe material inspection before installation 4. Trenching 5. Pipe-laying 6. Bedding and embedment around the pipe 7. Backfill over the pipeline 8. External and internal field joints 9. Internal pipe inspection after installation 10. Inspection of appurtenances 11. Patching of coating and lining 12. Installation through tunnels 13. Hydrostatic, compaction, and non-destructive testing of pipelines.