The influences of soil and nearby structures on dispersion characteristics of wave propagating along buried plastic pipes

Water loss in distribution systems is a global problem for the water industry and governments. According to the international water supply association (IWSA), as a result of leaks from distribution pipes, 20% to 30% of water is lost while transit from treatment plants to consumers. Although governments have tried to push water industry to reduce the water leaks, a lot of experts have pointed out that a wide use of plastic pipes instead of metal pipes in recent years has caused difficulties in the detection of leaks using current acoustic technology. Leaks from plastic pipes are much quieter than traditional metal pipes and comparing to metal pipes the plastic pipes have very different coupling characteristics with soil, water and surrounding structures, such as other pipes, road surface and building foundations. The dispersion characteristics of wave propagating along buried plastic pipe is investigated in this paper using finite element and boundary element based models (COMSOL and WANDS). Both empty and water-filled pipes were considered. Influences from nearby pipes and building foundation were carefully studied. The results showed that soil condition and surrounding structures have significant influences on the wave’s dispersion characteristics