Geosynthetic Reinforcement of Buried Flexible Pipes

Buried pipes perform a key role in urban centers, including multiple functions from fluid transport to electric lines conduction. Usually, flexible pipes design is developed by means of approximate formulations derived from the elasticity theory (v.g. Spangler Iowa). Although there are many studies about the interaction between a soil and a buried pipe, several failures are observed in these systems. In order to reduce the pipe deflections and stresses, the system reinforcement with a geosyntethic is proposed. The present paper shows the results of a parametric study about the interaction between a flexible buried pipe (e.g. polyester reinforced with fiberglass pipe – PRFV) with the surrounding soil and a geosynthetic acting as a reinforcement element. For the analysis of the soil-pipe-geosynthetic interaction and behavior, a bidimensional finite element model was built using PLAXIS software. By means of the numeric model, the contribution of the geosynthetic as a function of the soil and pipe stiffness was determined. The influence of the geosynthetic burial depth on the pipe deflection is also analyzed. The maximum geosynthetic contribution is observed for the case of pipe trenches excavated on rigid natural soils backfilled with softly compacted materials in order to avoid pipe damage.