AWWA INF52174

A field instrumentation system was successfully installed to monitor the performance of ahigh-density polyethylene (HDPE) sliplined 83-year old 910-mm diameter cast iron water main in Ottawa, Ontario, Canada. This monitoring system included various sensors to measure strains in both pipe walls, the internal hydrostaticpressure, the in-situ soil moisture contents and the temperature profiles in the soil backfill.The work included the insertion of sections of the HDPE pipe with sensors and cablesattached during the rehabilitation of the entire 1.5-km water line. The installation thereforerequired the collaborative effort of the research team, the owner, the consultant and thegeneral contractor for the rehabilitation project. About 50% of the installed strain gauges andabout 95% of the installed thermocouples survived the installation process. The preliminaryresults based on the first four months of data show that the measured strain ranges in the HDPEpipe were within the ranges predicted using the short- and long-term modulus of elasticity ofthe HDPE material. The results have confirmed the assumption that bonding at the interfacesbetween the HDPE and the grout and between the grout and the cast iron pipe was negligible.The results also show that the granular C backfill material above the pipe had littleinsulation capacity and that the soil around the water main is likely to freeze over the winter. Includes 9 references, tables, figures.

Product Details

Edition:

Vol. - No.

Published:

01/01/2000

Number of Pages:

21

File Size:

1 file , 1.9 MB