Experimental and numerical simulation of formed-in-place pipe liner for repairing water mains with void

Abstract

The failure pressure of the rehabilitated pressure pipe-lined system is related to several factors including the void in the host pipe. In this paper, the internal pressure resistance test of FIPP (Formed-In-Place Pipe) liner spanning the circular voids of the host pipe is carried out. The relationship among the strain, vertical displacement and internal pressure of the FIPP liner is studied. A three-dimensional finite element model of the host pipeline-FIPP liner system was established based on ABAQUS to investigate the stress distribution disciplinarian of the FIPP lining surface and the stress loading path of critical elements were investigated. Considering the influence of circular voids with different diameters on the failure pressure of FIPP lining pipes, numerical study of DN300 FIPP lining with a wall thickness of 5 mm is carried out. The results show that the hoop stress in the center of the void is always greater than the stress in other positions. Axial rupture is the main failure mode of the FIPP lining under the hoop stress at the center point. The maximum stress criterion is accurate and reliable when used to estimate the failure pressure of the FIPP lining. The larger ratio of void diameter to pipe diameter leads to smaller failure pressure of the lining. These results support further trenchless rehabilitation technology development of FIPP lining design and widespread applications.