Re-Rounding of Deflected Thermoplastic Pipes
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Ohio University / OhioLINK
2020
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| Online Access: | http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1604928370401047 |
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ndltd-OhioLink-oai-etd.ohiolink.edu-ohiou16049283704010472021-08-03T07:16:31Z Re-Rounding of Deflected Thermoplastic Pipes White, Kevin E. Civil Engineering Engineering Geotechnology Plastics Soil-Structure Interaction Pipeline Remediation Thermoplastic Pipes Culverts High-Density Polyethylene is a frequently utilized thermoplastic for the manufacture of stormwater drainage pipe in both public and private construction projects. Research on thermoplastic pipes shows that thermoplastic pipes, when installed properly, have sufficient structural resistance to withstand soil loads as great as 40 feet of soil cover; however, there continue to be isolated instances of poor field performance and excessive deflection.Installation deformation of thermoplastic pipe is limited by Ohio Department of Transportation specifications to a vertical deflection limit of 7.5 percent of the pipe’s inner vertical diameter. Thermoplastic pipes that have experienced vertical deflection greater than this 7.5 percent limit, without structural defects, are routinely remediated using a technique called re-rounding. Very little is known about the process from a mechanistic perspective. Independent research is needed to thoroughly understand the re-rounding process and to ascertain the impacts of re-rounding on thermoplastic pipe installations.The main objective of this investigation is to validate re-rounding as a viable remediation technique for HDPE pipe exceeding maximum allowable deflection and examine the long-term serviceability of the re-rounded pipe and any overlying pavement. The viability was assessed by investigating the impact of the magnitude of deflection, the quality of the backfill material, and the elapsed time after backfilling, on the resulting performance of re-rounding. A series of three test pipe experiments were conducted to investigate the re-rounding process. Pipes were installed under controlled conditions, including three types of backfill and two target deflection levels. Instrumentation and temporal measurements include the test pipes’ shape, the profile corrugation height, the backfill pressures, backfill stiffness, and the condition of the exhumed pipe.The results of each measure are summarized as follows:•All three ODOT standard backfill materials appear to permit re-rounding to some degree. •The results of the field tests indicate that the upper deflection limit for a pipe to be viable for re-rounding is related mainly to the structural strain capacity of the pipe. •The re-rounding process does not damage the pipe.•A conservative minimum height of cover of 50 in above the pipe will ensure the pavement is not damaged. •Re-rounding appears to be a sustainable remediation technique for the long-term.Finite element analyses were also performed to model the poor installations common with over-deflected pipe and the re-rounding process. The finite element analyses were only partially successful in modeling the pipe during the re-rounding process. 2020 English text Ohio University / OhioLINK http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1604928370401047 http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1604928370401047 unrestricted This thesis or dissertation is protected by copyright: all rights reserved. It may not be copied or redistributed beyond the terms of applicable copyright laws. |
| collection |
NDLTD |
| language |
English |
| sources |
NDLTD |
| topic |
Civil Engineering Engineering Geotechnology Plastics Soil-Structure Interaction Pipeline Remediation Thermoplastic Pipes Culverts |
| spellingShingle |
Civil Engineering Engineering Geotechnology Plastics Soil-Structure Interaction Pipeline Remediation Thermoplastic Pipes Culverts White, Kevin E. Re-Rounding of Deflected Thermoplastic Pipes |
| author |
White, Kevin E. |
| author_facet |
White, Kevin E. |
| author_sort |
White, Kevin E. |
| title |
Re-Rounding of Deflected Thermoplastic Pipes |
| title_short |
Re-Rounding of Deflected Thermoplastic Pipes |
| title_full |
Re-Rounding of Deflected Thermoplastic Pipes |
| title_fullStr |
Re-Rounding of Deflected Thermoplastic Pipes |
| title_full_unstemmed |
Re-Rounding of Deflected Thermoplastic Pipes |
| title_sort |
re-rounding of deflected thermoplastic pipes |
| publisher |
Ohio University / OhioLINK |
| publishDate |
2020 |
| url |
http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1604928370401047 |
| work_keys_str_mv |
AT whitekevine reroundingofdeflectedthermoplasticpipes |
| _version_ |
1719458066701746176 |