A platform for research: civil engineering, architecture and urbanism
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This paper explores the various mechanisms responsible for the failure of geotextile tubes during filling. Geotextile tubes are designed to withstand the rigors of hydraulic filling. While failures are quite rare, they usually happen during filling or immediately after repeated pumpings. When tubes are used for dewatering slurries, they are generally subject to multiple fillings. Each filling subjects the tube to circumferential and axial stresses which cause elongation of the yarns. Repeated cycles can cause fatigue resulting in rupture. Six geotextile tube fabrics were tested using a modified ASTM D 4595 test which increased the tension to 325 pounds per inch in three cycles. During the third cycle, the geotextile was pulled to failure. The five polypropylene fabrics and one polyester fabric were tested in both the machine and cross machine directions. This paper will compare the stress - strain curves and relate the results to actual failures seen in full scale tube projects. In summary, while failures remain infrequent, they can be minimized even further through a better understanding of the physical properties of the geotextiles that make up the tubes. Standard tube geotextiles have been designed for the rigors of most filling applications, and this includes the seams, both longitudinal and circumferential. Actual field conditions, which include foundation slopes, dissimilar fill materials, and gaps under tubes can be accounted for in the design of the fabric and in the recommended fill height, or in the contractor's construction methodology. For example, when designing tubes to be stacked, the specified fill height should account for the possibility of a gap under the tube. In other words, either a factor of safety should be applied, or the additional step of determining that the tensile strength in the scenario of cyclical stress and void space under the tube is adequate. A very small data set was used in the development of this paper. It is recommended that more testing be accomplished to increase the size of the data set. Based on the above test results which show a loss of tensile strength due to cyclical stress, further analysis should be done to establish a rule of thumb to account for this loss. At a minimum, project owners and engineers should ensure that the design of large dewatering projects, especially stacked tubes on contaminated sites, has addressed the potential for the types of failures identified.
This paper explores the various mechanisms responsible for the failure of geotextile tubes during filling. Geotextile tubes are designed to withstand the rigors of hydraulic filling. While failures are quite rare, they usually happen during filling or immediately after repeated pumpings. When tubes are used for dewatering slurries, they are generally subject to multiple fillings. Each filling subjects the tube to circumferential and axial stresses which cause elongation of the yarns. Repeated cycles can cause fatigue resulting in rupture. Six geotextile tube fabrics were tested using a modified ASTM D 4595 test which increased the tension to 325 pounds per inch in three cycles. During the third cycle, the geotextile was pulled to failure. The five polypropylene fabrics and one polyester fabric were tested in both the machine and cross machine directions. This paper will compare the stress - strain curves and relate the results to actual failures seen in full scale tube projects. In summary, while failures remain infrequent, they can be minimized even further through a better understanding of the physical properties of the geotextiles that make up the tubes. Standard tube geotextiles have been designed for the rigors of most filling applications, and this includes the seams, both longitudinal and circumferential. Actual field conditions, which include foundation slopes, dissimilar fill materials, and gaps under tubes can be accounted for in the design of the fabric and in the recommended fill height, or in the contractor's construction methodology. For example, when designing tubes to be stacked, the specified fill height should account for the possibility of a gap under the tube. In other words, either a factor of safety should be applied, or the additional step of determining that the tensile strength in the scenario of cyclical stress and void space under the tube is adequate. A very small data set was used in the development of this paper. It is recommended that more testing be accomplished to increase the size of the data set. Based on the above test results which show a loss of tensile strength due to cyclical stress, further analysis should be done to establish a rule of thumb to account for this loss. At a minimum, project owners and engineers should ensure that the design of large dewatering projects, especially stacked tubes on contaminated sites, has addressed the potential for the types of failures identified.
Geotextile Tube Failures
Gaffney, Douglas A. (author)
2013
9 Seiten, Bilder, Tabellen, Quellen
Conference paper
Storage medium
English