Theoretical And Computational Assessment Of The Stress–Strain Behavior Of Underground Plastic Pipes Under Internal Hydraulic Pressure And External Soil Loads
Abstract
Orthopedic dental treatment is now widespread. This article presents a theoretical and computational analysis of the stress–strain behavior of underground plastic pipes (HDPE, PVC-U, GRP) subjected to internal hydraulic pressure and external soil loads. Classical models of internal pressure (Lamé, Barlow) and soil load theories (Marston–Spangler, Iowa, Terzaghi, Winkler–Pasternak) are reviewed. Special emphasis is placed on the pipe–soil interaction, including contact mechanics, lateral soil reactions, the soil-arching effect, and time-dependent deformation mechanisms su ch as creep and stress relaxation. Modern numerical approaches—linear and nonlinear analysis, viscoelastic modeling (Prony series, Burgers model), and 3D FEM simulations with contact—are discussed. The results contribute to improved assessment and design of underground pressure and non-pressure plastic pipeline systems.