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Title Material Characterization and Testing of Cured-in-Place Pipe to Resist Earthquake Related Ground Deformation
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Publication Date
Date Accessioned
Degree M.S., Civil and Environmental Engineering
Discipline/Department Civil and Environmental Engineering
Degree Level masters
University/Publisher Cornell University
Abstract This thesis summarizes the testing procedures and key results of full-scale tests on Cured-In-Place Pipe (CIPP) to evaluate its performance under earthquake induced ground deformation. The CIPP used in this work is commercially available as Aqua-pipe, manufactured by Sanexen Environmental Services, Inc. to rehabilitate water mains. The investigation covered in this work includes tensile coupon tests, direct tension tests, friction tests, and direct shear tests. The test results improve the understanding and characterization of the axial force vs. displacement relationship for CIPP movement relative to the host pipe, lining/pipe interface friction, and the effects of geometry, internal pressure, and repeated loading on the axial force vs. relative displacement relationship. The direct tension test results show that the mobilization of axial force is affected by Mode II fracture propagation, friction between the exterior surface of the lining and interior surface of the host pipe, and geometric resistance generated by the relative movement of the lining within a host pipe of variable inside diameter. The most important finding from the direct tension tests is that substantial additional axial forces may be mobilized after debonding as the lining is affected by geometric interference caused by movement through a pipe with variable internal diameter. The test results provide a first-time confirmation of this loading mechanism. The friction tests show that the axial load response is independent of loading rate, with a similar load range and maximum load for the tests conducted at 1 in. (25 mm)/min, 10 in. (250 mm)/min, and 100 in. (2500 mm)/min. The first friction test, done under no pressure, developed larger axial forces due to the greater frictional resistance between the lining and pipe than in a subsequent test under the same testing conditions and geometry. The difference in the axial loads show that over-cleaned field pipes or new ductile iron pipes can have a greater frictional resistance between the lining and pipe than properly cleaned or previously loaded pipes. The most important result from the friction tests involves the influence of internal pressure on axial load response. As the internal pressure increased, the axial load for a given displacement increased linearly. Regressions of axial load vs. internal pressure at the same levels of displacement show a clear linear relationship with similar slopes. The results of the direct shear tests for new ductile iron and field cast iron pipes show a coefficient of friction of 0.61. This value represents the relatively smooth debonded lining surface conditions representative of the CIPP cleaning and lining process for old cast iron water mains. It also represents the interface between the lining and new ductile iron pipe after repeated displacements. The test results show that a coefficient of friction of 0.84 is a good estimate for lining/pipe interfaces that are rough and irregular.
Subjects/Keywords Civil engineering; cured-in-place; deformation; pipeline; earthquake
Contributors O'Rourke, Thomas Denis (chair); Stewart, Harry Eaton (committee member)
Language en
Country of Publication us
Record ID handle:1813/67679
Repository cornell
Date Retrieved
Date Indexed 2020-09-09
Grantor Cornell University
Issued Date 2019-08-30 00:00:00

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