An experimental study on investigating the impacts of a localised saturated zone around an intact buried pipe on a pavement

The interdependencies between road, the ground and buried utilities within an urban infrastructure system complicate the management of an urban infrastructure system. Consequently, it is crucial to adopt a comprehensive approach to infrastructure maintenance, by considering the interdependencies within the entire system. Understanding the correlation between these components can help identify the main causes of failure leading to more efficient management practices. While various studies have investigated the effect of traffic loads on buried pipes, fewer studies have examined how a localised saturated zone around an intact buried pipe influences road surface deterioration. In this study, laboratory experiments were conducted to investigate the coupled response of the pavement, soil, and pipe under cyclic loading when such a localised saturated zone was introduced. The results showed that localised surface depression of the road was exacerbated when a saturated zone was present around the intact buried pipe, which indicates a greater potential for accelerated pavement deterioration. The study is intended as a comparative reduced-scale physical model for mechanism interpretation rather than a direct prototype prediction. The findings suggest that localised saturation around buried utilities may contribute to accelerated pavement deterioration and may therefore be relevant to condition assessment and maintenance prioritisation.