Numerical Analysis of Flexible Pipes Buried in Cohesionless Soil

Abstract

Pipelines are an important element of modern infrastructure as they are the carrier of essential transportation materials. The proper knowledge of the soil-pipe interaction mechanism leads to the better performance of the buried pipe system. This paper describes the study of the behavior of a flexible pipe, buried in sandy soil. Numerical analysis was performed using MIDAS GTS NX finite element software. A pipe having an outer diameter of 0.45 m and 10 mm thickness, subjected to the strip surface load was modeled. The strip load was varied from 0 to 100 kPa. Two types of pipe materials, namely; Polyvinyl Chloride (PVC) and High-Density Polyethylene (HDPE) were examined. The analysis was performed in loose, medium dense, and dense sandy soil; with different burial depths of pipe, having embedment ratio 1,2 and 3. The analysis revealed the decreasing nature of pipe deflection with the increase in embedment depth, whereas the crown stress was found to be minimum for the embedment ratio 2. The detailed analysis showing the influence of pipe stiffness, soil stiffness, and pipe burial depth on the vertical pipe deflection and crown stress is presented in this paper.