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Title: PIPE FAILURE CAUSED BY IMPROPER GROUNDWATER CONTROL
Accession Number: 00666215
Record Type: Component
Availability: Find a library where document is available Abstract: A sewer collection system installed in a Middle Eastern city incorporated 11 km of fiberglass reinforced plastic mortar (RPM) sewer pipe 500 to 1100 mm in diameter. A short time after installation it was discovered that the pipelines were highly deflected and that some pipe was cracked at the crown. Subsequently a number of the cracked pipes failed, causing large craters and collapse of the roadway. Inspections showed that more than one-half of the RPM pipe system was deflected well over 5%, the limit imposed by the contract documents, with some portions deflected up to about 20% of their original diameter, and that numerous sections of pipe were cracked at the crown. Investigation of the conditions at the sites showed that the deflections and failures resulted mainly from inadequate control of the groundwater during construction and improper attention to the grading of the crushed stone pipe embedment relative to the natural sand materials against which it was placed. During construction the dewatering system did not maintain the groundwater level below the trench bottom, resulting in water washing into the trench through open sheeting joints, carrying sand with it and leaving cavities behind the sheeting. When the sheeting was pulled, the stone embedment lost support and moved into the cavities, allowing high pipe deflections. Migration of fines and the native sands into the voids in the open graded stone is also believed to have contributed to the loss of pipe support gradually after construction.
Supplemental Notes: This paper appears in Transportation Research Record No. 1431, Culvert Distress and Failure Case Histories and Trenchless Technology. Distribution, posting, or copying of this PDF is strictly prohibited without written permission of the Transportation Research Board of the National Academy of Sciences. Unless otherwise indicated, all materials in this PDF are copyrighted by the National Academy of Sciences. Copyright © National Academy of Sciences. All rights reserved
Monograph Title: Culvert distress and failure case history and trenchless technology Monograph Accession #: 01401234
Language: English
Authors: Selig, Ernest TMcGrath, Timothy JPagination: p. 22-26
Publication Date: 1994
Serial: ISBN: 0309055091
Features: Figures
(4)
; References
(2)
TRT Terms: Uncontrolled Terms: Old TRIS Terms: Subject Areas: Bridges and other structures; Geotechnology; Highways; Safety and Human Factors; I20: Design and Planning of Transport Infrastructure; I42: Soil Mechanics
Files: TRIS, TRB
Created Date: Sep 15 1994 12:00AM
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