Principal, Simpson Gumpertz & Heger Inc., Consulting Engineers, Arlington, MA
Principal, E.T. Selig, Inc., Hadley, MA
Geotechnical Engineer, GFJ (Pty) Ltd., Consulting Engineers and Project Managers, Hatfield,
Pages: 16 Published: Jan 2000
Full-scale field tests were conducted on the campus of the University of Massachusetts, Amherst, to evaluate the pipe-soil interactions that take place as pipes are buried and backfilled. The program included concrete, polyethylene, and corrugated steel pipe. This paper focuses on the data from the concrete pipe tests, and assesses it in light of the assumptions of the SIDD design approach adopted by ASCE and AASHTO.
Tests included two types of soil backfill, three compaction levels, three trench widths, varying haunching effort and one test with controlled low strength material. Eleven tests were conducted with 900 mm (36 in.) inside diameter pipe and three installations with 1500 mm (60 in.) inside diameter pipe. Primary measurements on the concrete pipe during backfilling and compaction included pipe-soil interface pressures, soil density, and soil stresses.
Results show significant variations in pipe behavior as a result of installation practices and generally confirm the assumptions of the SIDD design method. Compaction of backfill in the region from the springline to 45 to 60 degrees below the springline has a significant positive effect in mitigating poor bedding and haunching conditions, and the use of soft bedding is effective in reducing invert pressures on the Pipe.
reinforced concrete pipe, pipe, backfill, compaction, instrumentation
Paper ID: STP14999S