Three-Dimensional Numerical Modeling and Full-Scale Tests of Cured-in-Place Pipe

The results of three-dimensional numerical modeling are compared with the results of full-scale tests on a pipeline reinforced with cured-in-place pipe (CIPP) performed at the Cornell Large-Scale Lifelines Facility. The results pertain to axial elongation to accommodate earthquake-induced ground deformation of a 6-in. (152-mm)-diameter ductile iron (DI) pipeline lined with ALTRA Proven Water Solutions, formerly known as Aqua-Pipe, Generation 1. Full-scale lab tests were designed to evaluate the axial resistance to relative movement between the host pipe and CIPP. A 24-in. (610-mm)-long section of DI pipe was pulled 36 in. (914 mm) across the CIPP under different rates of axial movement and internal pressure. Both the DI pipe and CIPP were modeled as elastic isotropic materials with Young’s modulus and Poisson’s ratio from tensile coupon test results. Three-dimensional, 8-node, linear interpolation, and full integration elements were used for the pipe and the liner in ABAQUS simulations. The number of elements per pipe and liner circumference was 32. Full-scale tests for internal pressures of 30, 45, and 75 psi (0.21, 0.31, and 0.52 MPa) indicated that the CIPP can sustain higher axial loads as internal pressure increases. The experimental results were shown to compare favorably with the numerical results. The numerical models are used to investigate the effects of initial CIPP diameter, changes in diameter with length, and diameter changes as a function of internal pressure. Rate of loading is shown experimentally to have negligible effects on axial load as a function of axial movement.