Reliability Analysis of Deflection of Buried Flexible Pipes

• Published in: Journal of transportation engineering Vol. 132; no. 10; pp. 829 - 836
• Main Authors: Sivakumar Babu, G. L, Srinivasa Murthy, B. R, Seshagiri Rao, R
• Format: Journal Article
• Language: English
• Published: Reston, VA American Society of Civil Engineers 01.10.2006
• Subjects: Applied sciences; Buildings. Public works; Exact sciences and technology; Failure analysis; Pipes; Piping; Reliability; Roads & highways; TECHNICAL PAPERS; Underground construction; Water supply. Pipings. Water treatment; Case study; Flexible pipe; Deflection; Buried pipe; Property of soil; Stiffness; Buried pipes; Measurement method; Safety; Reliability; Computing method; Flexibility
• ISSN: 0733-947X; 1943-5436
• DOI: 10.1061/(ASCE)0733-947X(2006)132:10(829)

The in situ behavior of buried flexible pipes is considerably influenced by uncertainties in external load, pipe, and soil properties. To take care of the uncertainties, while the conventional design methodology incorporates conservative factors of safety, it is desirable that these aspects of variability be incorporated in the design. In this paper, uncertainties in calculation of pipe deflection are reviewed. Soil stiffness and load are considered as random variables. Reliability assessment of deflection of a typical pipe section with typical soil properties is conducted using the point estimate method with respect to two reliability measures, central factor of safety and safety margin. Within the framework of analysis, results show that for flexible pipes, the conventional tolerable deflection limit of 5% of diameter of the pipe with respect to a factor of safety of 4 is conservative.