STABILITY OF LOOSELY FITTED LINERS USED TO REHABILITATE RIGID PIPES

Lining of rigid pipelines has emerged as a competitive alternative sol ution to conventional pipeline replacement. Due to the nature of the l iner installation process, the final liner may end up being loosely fi tted into the damaged pipeline. The liner should safely carry any exte rnal pressure due to the ground water. This study considers the effect of an initial gap between the circular liner and the circular host pi pe on the critical buckling pressure. The finite-element method is use d for the evaluation of the critical pressure for loosely fitted circu lar liners. The interface between the circular liner and the host pipe s is assumed to be smooth. A brief description of the finite-element m odel and the analysis is given, followed by a parametric study for the effect of gap size and liner thickness-to-radius ratio on the stabili ty of the liner. The results of this study are reported in a form suit able for design purposes. The work includes comparisons between the wr iters' numerical solution and previous theoretical solutions and exper imental work.