Numerical simulations on shapes and materials and deterioration model of flexible sewer systems

Abstract

Flexible pipes have been used widely in the sewer pipe system due to its low cost and easy construction compared to rigid pipes. Mechanical strength of various types of flexible pipes, such as PVC and PE, can be increased by their geometric structures. For example, the double-walled tubes were introduced to enhance the radial strength and their material properties were improved by the addition of reinforcing agent such as glass fiber. However, there have been rarely systematic studies regarding detailed material properties for various types of the structure and material. In this study, we numerically analyzed mechanical properties of flexible pipes with various types by the finite element method. As a result, we find the dependence of the deformation behavior both on the type of material and the structure of the pipe for various circumstances. On the other hand, these simulation results could be useful for estimating pipe deterioration process, since many years of observation are needed to estimate the pipe deterioration process but flexible pipes started being used recently and hence there exists rare observed deterioration data. So, we roughly estimate the deterioration process of flexible pipes in terms of geometric structures and materials.