Modelling the effect of climate change induced soil settling on jointed drinking water distribution pipes

Abstract

Soil settlements related to groundwater lowering are expected to be accelerated by climate change and may damage underground infrastructure networks. A 1D mechanical model, previously developed for continuous pipelines, has been extended towards jointed pipelines to calculate the stresses and joint rotations induced by the soil settlements. From the mechanical model, curve fits were acquired that can be used to estimate the bending moments and joint rotation. The curve fits differ per soil type, joint stiffness, joint position and joint distance. The stresses calculated by the 1D mechanical model and curve fits were validated by means of 3D finite element modelling. Using the curve fits, a probabilistic approach was followed by means of a Monte Carlo method to calculate the probability of failure of the pipeline system. The effect of joints is that the pipe stresses are reduced as the joints absorb a part of the soil displacement. For the probability of failure, the pipe stresses have a larger contribution than the joint rotation, as the joint rotation remains small compared to the maximum allowable joint rotation.