Response of buried pipeline subjected to reverse faulting: Fid-Bau Portal

Response of buried pipeline subjected to reverse faulting

Fadaee, M. / Farzaneganpour, F. / Anastasopoulos, I.

Abstract The paper studies the interaction of buried pipelines with a reverse fault rupture, employing 3D finite element (FE) modelling. A thoroughly validated strain softening constitutive model is employed to conduct a parametric study, exploring the effect of sediment thickness, pipeline burial depth and thickness. It is shown that the increase of sediment thickness $H$ leads to a reduction of the normalized fault offset $h / H$ at which buckling is initiated. Two contradicting mechanisms are identified: (i) the increase of $H$ leads to a reduction of the intersection angle $α$ of the fault rupture with the pipe, increasing the compressive component; and (ii) it leads to a reduction of localized deformation close to the surface. From our results, the $h / H$ required for initiation of buckling is insensitive to burial depth $H_{p} / D$ , but the one required for pipe rupture increases substantially with increase of $H_{p} / D$ . The increase of the $D / t$ (pipe diameter to wall thickness) ratio leads to a substantial decrease of the $h / H$ at which buckling is initiated, and the same applies to the pipe rupture criteria, which are met at a smaller $h / H$ with the increase of $D / t$ .

Highlights • Sediment thickness, pipe burial depth, and its thickness on response of pipeline subjected to reverse fault are investigated. • Sediment thickness is a key factor in the response of pipeline in case of reverse fault rupture. • Reduction of intersection angle of fault rupture with the pipe by increase of sediment thickness affects the pipe response.